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  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    2. 

  2. <html>
    3. 

  3. <head>
    4. 

  4.   <meta http-equiv="Content-Type" content="text/html">
    5. 

  5.   <title>Erubis Users' Guide</title>
    6. 

  6.   <meta name="generator" content="kwaser">
    7. 

  7.   <meta http-equiv="Content-Style-Type" content="text/css">
    8. 

  8.   <link rel="stylesheet" href="docstyle.css" type="text/css">
    9. 

  9.  </head>
    10. 

  10.  <body>
    11. 

  11. 

  12.   <blockquote>
    13. 

  13.    <div class="mainbody">
    14. 

  14. 

  15.     <div align="left"><h1>Erubis Users' Guide</h1></div>
    16. 

  16.     <div align="left">
    17. 

  17.       release:     2.6.6<br>
    18. 

  18.       last update: $Date$<br>
    19. 

  19.     </div>
    20. 

  20. 

  21. <p>release: 2.6.6
    22. 

  22. </p>
    23. 

  23. <a name="preface"></a>
    24. 

  24. <h2 class="section1">Preface</h2>
    25. 

  25. <p>Erubis is an implementation of eRuby.
    26. 

  26. It has the following features.
    27. 

  27. </p>
    28. 

  28. <ul type="disc">
    29. 

  29. <li>Very fast, almost three times faster than ERB and about ten percent faster than eruby (implemented in C)
    30. 

  30. </li>
    31. 

  31. <li>File caching of converted Ruby script support
    32. 

  32. </li>
    33. 

  33. <li>Auto escaping support
    34. 

  34. </li>
    35. 

  35. <li>Auto trimming spaces around '&lt;% %&gt;'
    36. 

  36. </li>
    37. 

  37. <li>Embedded pattern changeable (default '&lt;% %&gt;')
    38. 

  38. </li>
    39. 

  39. <li>Enable to handle Processing Instructions (PI) as embedded pattern (ex. '&lt;?rb ... ?&gt;')
    40. 

  40. </li>
    41. 

  41. <li>Multi-language support (Ruby/PHP/C/Java/Scheme/Perl/Javascript)
    42. 

  42. </li>
    43. 

  43. <li>Context object available and easy to combine eRuby template with YAML datafile
    44. 

  44. </li>
    45. 

  45. <li>Print statement available
    46. 

  46. </li>
    47. 

  47. <li>Easy to expand and customize in subclass
    48. 

  48. </li>
    49. 

  49. <li><a href="#rails">Ruby on Rails support</a>
    50. 

  50. </li>
    51. 

  51. <li>mod_ruby support|#topcs-modruby
    52. 

  52. </li>
    53. 

  53. </ul>
    54. 

  54. <p>Erubis is implemented in pure Ruby.  It requires Ruby 1.8 or higher.
    55. 

  55. Erubis now supports Ruby 1.9.
    56. 

  56. </p>
    57. 

  57. <a name="toc"></a>
    58. 

  58. <h3 class="section2">Table of Contents</h3>
    59. 

  59. <ul>
    60. 

  60.   <li><a href="#preface">Preface</a>
    61. 

  61.   <ul>
    62. 

  62.     <li><a href="#toc">Table of Contents</a>
    63. 

  63.     </li>
    64. 

  64.   </ul>
    65. 

  65.   </li>
    66. 

  66.   <li><a href="#install">Installation</a>
    67. 

  67.   </li>
    68. 

  68.   <li><a href="#tutorial">Tutorial</a>
    69. 

  69.   <ul>
    70. 

  70.     <li><a href="#tut-basic">Basic Example</a>
    71. 

  71.     </li>
    72. 

  72.     <li><a href="#tut-trim">Trimming Spaces</a>
    73. 

  73.     </li>
    74. 

  74.     <li><a href="#tut-escape">Escape</a>
    75. 

  75.     </li>
    76. 

  76.     <li><a href="#tut-pattern">Embedded Pattern</a>
    77. 

  77.     </li>
    78. 

  78.     <li><a href="#tut-context">Context Object</a>
    79. 

  79.     </li>
    80. 

  80.     <li><a href="#tut-datafile">Context Data File</a>
    81. 

  81.     </li>
    82. 

  82.     <li><a href="#tut-datastr">Context Data String</a>
    83. 

  83.     </li>
    84. 

  84.     <li><a href="#tut-preamble">Preamble and Postamble</a>
    85. 

  85.     </li>
    86. 

  86.     <li><a href="#tut-pi">Processing Instruction (PI) Converter</a>
    87. 

  87.     </li>
    88. 

  88.     <li><a href="#tut-notext">Retrieve Ruby Code</a>
    89. 

  89.     </li>
    90. 

  90.   </ul>
    91. 

  91.   </li>
    92. 

  92.   <li><a href="#enhancer">Enhancer</a>
    93. 

  93.   <ul>
    94. 

  94.     <li><a href="#escape-enhancer">EscapeEnhancer</a>
    95. 

  95.     </li>
    96. 

  96.     <li><a href="#stdout-enhancer">StdoutEnhancer</a>
    97. 

  97.     </li>
    98. 

  98.     <li><a href="#printout-enhancer">PrintOutEnhancer</a>
    99. 

  99.     </li>
    100. 

  100.     <li><a href="#printenabled-enhancer">PrintEnabledEnhancer</a>
    101. 

  101.     </li>
    102. 

  102.     <li><a href="#array-enhancer">ArrayEnhancer</a>
    103. 

  103.     </li>
    104. 

  104.     <li><a href="#arraybuffer-enhancer">ArrayBufferEnhancer</a>
    105. 

  105.     </li>
    106. 

  106.     <li><a href="#stringbuffer-enhancer">StringBufferEnhancer</a>
    107. 

  107.     </li>
    108. 

  108.     <li><a href="#erbout-enhancer">ErboutEnhancer</a>
    109. 

  109.     </li>
    110. 

  110.     <li><a href="#notext-enhancer">NoTextEnhancer</a>
    111. 

  111.     </li>
    112. 

  112.     <li><a href="#nocode-enhancer">NoCodeEnhancer</a>
    113. 

  113.     </li>
    114. 

  114.     <li><a href="#simplify-enhancer">SimplifyEnhancer</a>
    115. 

  115.     </li>
    116. 

  116.     <li><a href="#bipattern-enhancer">BiPatternEnhancer</a>
    117. 

  117.     </li>
    118. 

  118.     <li><a href="#percentline-enhancer">PercentLineEnhancer</a>
    119. 

  119.     </li>
    120. 

  120.     <li><a href="#headerfooter-enhancer">HeaderFooterEnhancer</a>
    121. 

  121.     </li>
    122. 

  122.     <li><a href="#interpolation-enhancer">InterpolationEnhancer</a>
    123. 

  123.     </li>
    124. 

  124.     <li><a href="#deleteindent-enhancer">DeleteIndentEnhancer</a>
    125. 

  125.     </li>
    126. 

  126.   </ul>
    127. 

  127.   </li>
    128. 

  128.   <li><a href="#lang">Multi-Language Support</a>
    129. 

  129.   <ul>
    130. 

  130.     <li><a href="#lang-php">PHP</a>
    131. 

  131.     </li>
    132. 

  132.     <li><a href="#lang-c">C</a>
    133. 

  133.     </li>
    134. 

  134.     <li><a href="#lang-java">Java</a>
    135. 

  135.     </li>
    136. 

  136.     <li><a href="#lang-scheme">Scheme</a>
    137. 

  137.     </li>
    138. 

  138.     <li><a href="#lang-perl">Perl</a>
    139. 

  139.     </li>
    140. 

  140.     <li><a href="#lang-javascript">JavaScript</a>
    141. 

  141.     </li>
    142. 

  142.   </ul>
    143. 

  143.   </li>
    144. 

  144.   <li><a href="#rails">Ruby on Rails Support</a>
    145. 

  145.   <ul>
    146. 

  146.     <li><a href="#rails-settings">Settings</a>
    147. 

  147.     </li>
    148. 

  148.     <li><a href="#rails-preprocessing">Preprosessing</a>
    149. 

  149.     </li>
    150. 

  150.     <li><a href="#rails-formhelpers">Form Helpers for Preprocessing</a>
    151. 

  151.     </li>
    152. 

  152.     <li><a href="#rails-others">Others</a>
    153. 

  153.     </li>
    154. 

  154.   </ul>
    155. 

  155.   </li>
    156. 

  156.   <li><a href="#topics">Other Topics</a>
    157. 

  157.   <ul>
    158. 

  158.     <li><a href="#'&lt;%= =%&gt;' and '&lt;%= -%&gt;'">'&lt;%= =%&gt;' and '&lt;%= -%&gt;'</a>
    159. 

  159.     </li>
    160. 

  160.     <li><a href="#'&lt;%% %&gt;' and '&lt;%%= %&gt;'">'&lt;%% %&gt;' and '&lt;%%= %&gt;'</a>
    161. 

  161.     </li>
    162. 

  162.     <li><a href="#topics-context-vs-binding">evaluate(context) v.s. result(binding)</a>
    163. 

  163.     </li>
    164. 

  164.     <li><a href="#topics-fasteruby">Class Erubis::FastEruby</a>
    165. 

  165.     </li>
    166. 

  166.     <li><a href="#topics-syntax">Syntax Checking</a>
    167. 

  167.     </li>
    168. 

  168.     <li><a href="#topics-caching">File Caching</a>
    169. 

  169.     </li>
    170. 

  170.     <li><a href="#topics-tinyeruby">Erubis::TinyEruby class</a>
    171. 

  171.     </li>
    172. 

  172.     <li><a href="#topics-php">NoTextEnhancer and NoCodeEnhancer in PHP</a>
    173. 

  173.     </li>
    174. 

  174.     <li><a href="#topcs-modruby">Helper Class for mod_ruby</a>
    175. 

  175.     </li>
    176. 

  176.     <li><a href="#topics-defmethod">Define method</a>
    177. 

  177.     </li>
    178. 

  178.     <li><a href="#topics-benchmark">Benchmark</a>
    179. 

  179.     </li>
    180. 

  180.   </ul>
    181. 

  181.   </li>
    182. 

  182.   <li><a href="#command">Command Reference</a>
    183. 

  183.   <ul>
    184. 

  184.     <li><a href="#command-usage">Usage</a>
    185. 

  185.     </li>
    186. 

  186.     <li><a href="#command-options">Options</a>
    187. 

  187.     </li>
    188. 

  188.     <li><a href="#command-props">Properties</a>
    189. 

  189.     </li>
    190. 

  190.   </ul>
    191. 

  191.   </li>
    192. 

  192. </ul>
    193. 

  193. <br>
    194. 

  194. 

  195. 

  196. <br>
    197. 

  197. 

  198. 

  199. <a name="install"></a>
    200. 

  200. <h2 class="section1">Installation</h2>
    201. 

  201. <ul type="disc">
    202. 

  202. <li>If you have installed RubyGems, just type <code>gem install --remote erubis</code>.
    203. 

  203. <pre class="terminal">$ sudo gem install --remote erubis
    204. 

  204. </pre>
    205. 

  205. </li>
    206. 

  206. </ul>
    207. 

  207. <ul type="disc">
    208. 

  208. <li>Else install <a href="http://rubyforge.org/projects/erubis/">abstract</a> at first,
    209. 

  209.    and download erubis_X.X.X.tar.bz2 and install it by setup.rb.
    210. 

  210. <pre class="terminal">$ tar xjf abstract_X.X.X.tar.bz2
    211. 

  211. $ cd abstract_X.X.X/
    212. 

  212. $ sudo ruby setup.rb
    213. 

  213. $ cd ..
    214. 

  214. $ tar xjf erubis_X.X.X.tar.bz2
    215. 

  215. $ cd erubis_X.X.X/
    216. 

  216. $ sudo ruby setup.rb
    217. 

  217. </pre>
    218. 

  218. </li>
    219. 

  219. </ul>
    220. 

  220. <ul type="disc">
    221. 

  221. <li>(Optional) 'contrib/inline-require' enables you to merge 'lib/**/*.rb' into 'bin/erubis'.
    222. 

  222. <pre class="terminal">$ tar xjf erubis_X.X.X.tar.bz2
    223. 

  223. $ cd erubis_X.X.X/
    224. 

  224. $ unset RUBYLIB
    225. 

  225. $ contrib/inline-require -I lib bin/erubis &gt; contrib/erubis
    226. 

  226. </pre>
    227. 

  227. </li>
    228. 

  228. </ul>
    229. 

  229. <br>
    230. 

  230. 

  231. 

  232. <a name="tutorial"></a>
    233. 

  233. <h2 class="section1">Tutorial</h2>
    234. 

  234. <a name="tut-basic"></a>
    235. 

  235. <h3 class="section2">Basic Example</h3>
    236. 

  236. <p>Here is a basic example of Erubis.
    237. 

  237. </p>
    238. 

  238. <a name="example1.eruby"></a>
    239. 

  239. <div class="program_caption">
    240. 

  240. example1.eruby</div>
    241. 

  241. <pre class="program">&lt;ul&gt;
    242. 

  242.   <strong>&lt;% for item in list %&gt;</strong>
    243. 

  243.   &lt;li&gt;<strong>&lt;%= item %&gt;</strong>&lt;/li&gt;
    244. 

  244.   <strong>&lt;% end %&gt;</strong>
    245. 

  245.   <strong>&lt;%# here is ignored because starting with '#' %&gt;</strong>
    246. 

  246. &lt;/ul&gt;
    247. 

  247. </pre>
    248. 

  248. <a name="example1.rb"></a>
    249. 

  249. <div class="program_caption">
    250. 

  250. example1.rb</div>
    251. 

  251. <pre class="program">require 'erubis'
    252. 

  252. input = File.read('example1.eruby')
    253. 

  253. eruby = <strong>Erubis::Eruby.new(input)</strong>    # create Eruby object
    254. 

  254. 

  255. puts "---------- script source ---"
    256. 

  256. puts <strong>eruby.src</strong>                      # print script source
    257. 

  257. 

  258. puts "---------- result ----------"
    259. 

  259. list = ['aaa', 'bbb', 'ccc']
    260. 

  260. puts <strong>eruby.result(binding())</strong>        # get result
    261. 

  261. ## or puts eruby.result(<strong>:list=&gt;list</strong>)  # or pass Hash instead of Binding
    262. 

  262. 

  263. ## # or
    264. 

  264. ## eruby = Erubis::Eruby.new
    265. 

  265. ## input = File.read('example1.eruby')
    266. 

  266. ## src = eruby.convert(input)
    267. 

  267. ## eval src
    268. 

  268. </pre>
    269. 

  269. <a name="example1.result"></a>
    270. 

  270. <div class="terminal_caption">
    271. 

  271. output</div>
    272. 

  272. <pre class="terminal">$ ruby example1.rb
    273. 

  273. ---------- script source ---
    274. 

  274. _buf = ''; _buf &lt;&lt; '&lt;ul&gt;
    275. 

  275. ';   for item in list 
    276. 

  276.  _buf &lt;&lt; '  &lt;li&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/li&gt;
    277. 

  277. ';   end 
    278. 

    279. 

  279.  _buf &lt;&lt; '&lt;/ul&gt;
    280. 

  280. ';
    281. 

  281. _buf.to_s
    282. 

  282. ---------- result ----------
    283. 

  283. &lt;ul&gt;
    284. 

  284.   &lt;li&gt;aaa&lt;/li&gt;
    285. 

  285.   &lt;li&gt;bbb&lt;/li&gt;
    286. 

  286.   &lt;li&gt;ccc&lt;/li&gt;
    287. 

  287. &lt;/ul&gt;
    288. 

  288. </pre>
    289. 

  289. <p>Erubis has command 'erubis'.  Command-line option '-x' shows the compiled source code of eRuby script.
    290. 

  290. </p>
    291. 

  291. <a name="example1_x.result"></a>
    292. 

  292. <div class="terminal_caption">
    293. 

  293. example of command-line option '-x'</div>
    294. 

  294. <pre class="terminal">$ erubis <strong>-x</strong> example1.eruby
    295. 

  295. _buf = ''; _buf &lt;&lt; '&lt;ul&gt;
    296. 

  296. ';   for item in list 
    297. 

  297.  _buf &lt;&lt; '  &lt;li&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/li&gt;
    298. 

  298. ';   end 
    299. 

    300. 

  300.  _buf &lt;&lt; '&lt;/ul&gt;
    301. 

  301. ';
    302. 

  302. _buf.to_s
    303. 

  303. </pre>
    304. 

  304. <br>
    305. 

  305. 

  306. 

  307. <a name="tut-trim"></a>
    308. 

  308. <h3 class="section2">Trimming Spaces</h3>
    309. 

  309. <p>Erubis deletes spaces around '&lt;% %&gt;' automatically, while it leaves spaces around '&lt;%= %&gt;'.
    310. 

  310. </p>
    311. 

  311. <a name="example2.eruby.comment_filter"></a>
    312. 

  312. <div class="program_caption">
    313. 

  313. example2.eruby</div>
    314. 

  314. <pre class="program">&lt;ul&gt;
    315. 

  315.   &lt;% for item in list %&gt;      # trimmed
    316. 

  316.   &lt;li&gt;
    317. 

  317.     &lt;%= item %&gt;               # not trimmed
    318. 

  318.   &lt;/li&gt;
    319. 

  319.   &lt;% end %&gt;                   # trimmed
    320. 

  320. &lt;/ul&gt;
    321. 

  321. </pre>
    322. 

  322. <a name="example2_x.result"></a>
    323. 

  323. <div class="terminal_caption">
    324. 

  324. compiled source code</div>
    325. 

  325. <pre class="terminal">$ erubis -x example2.eruby
    326. 

  326. _buf = ''; _buf &lt;&lt; '&lt;ul&gt;
    327. 

  327. ';   for item in list 
    328. 

  328.  _buf &lt;&lt; '  &lt;li&gt;
    329. 

  329.     '; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '
    330. 

  330. '; _buf &lt;&lt; '  &lt;/li&gt;
    331. 

  331. ';   end 
    332. 

  332.  _buf &lt;&lt; '&lt;/ul&gt;
    333. 

  333. ';
    334. 

  334. _buf.to_s
    335. 

  335. </pre>
    336. 

  336. <p>If you want leave spaces around '&lt;% %&gt;', add command-line property '--trim=false'.
    337. 

  337. </p>
    338. 

  338. <a name="example2_trim.result"></a>
    339. 

  339. <div class="terminal_caption">
    340. 

  340. compiled source code with command-line property '--trim=false'</div>
    341. 

  341. <pre class="terminal">$ erubis -x <strong>--trim=false</strong> example2.eruby
    342. 

  342. _buf = ''; _buf &lt;&lt; '&lt;ul&gt;
    343. 

  343. '; _buf &lt;&lt; '  '; for item in list ; _buf &lt;&lt; '
    344. 

  344. '; _buf &lt;&lt; '  &lt;li&gt;
    345. 

  345.     '; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '
    346. 

  346. '; _buf &lt;&lt; '  &lt;/li&gt;
    347. 

  347. '; _buf &lt;&lt; '  '; end ; _buf &lt;&lt; '
    348. 

  348. '; _buf &lt;&lt; '&lt;/ul&gt;
    349. 

  349. ';
    350. 

  350. _buf.to_s
    351. 

  351. </pre>
    352. 

  352. <p>Or add option <code>:trim=&gt;false</code> to Erubis::Eruby.new().
    353. 

  353. </p>
    354. 

  354. <a name="example2.rb"></a>
    355. 

  355. <div class="program_caption">
    356. 

  356. example2.rb</div>
    357. 

  357. <pre class="program">require 'erubis'
    358. 

  358. input = File.read('example2.eruby')
    359. 

  359. eruby = Erubis::Eruby.new(input<strong>, :trim=&gt;false</strong>)
    360. 

  360. 

  361. puts "----- script source ---"
    362. 

  362. puts eruby.src                            # print script source
    363. 

  363. 

  364. puts "----- result ----------"
    365. 

  365. list = ['aaa', 'bbb', 'ccc']
    366. 

  366. puts eruby.result(binding())              # get result
    367. 

  367. </pre>
    368. 

  368. <a name="example2.result"></a>
    369. 

  369. <div class="terminal_caption">
    370. 

  370. output</div>
    371. 

  371. <pre class="terminal">$ ruby example2.rb
    372. 

  372. ----- script source ---
    373. 

  373. _buf = ''; _buf &lt;&lt; '&lt;ul&gt;
    374. 

  374. '; <strong>_buf &lt;&lt; '  ';</strong> for item in list ; _buf &lt;&lt; '
    375. 

  375. '; _buf &lt;&lt; '  &lt;li&gt;
    376. 

  376.     '; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '
    377. 

  377. '; _buf &lt;&lt; '  &lt;/li&gt;
    378. 

  378. '; <strong>_buf &lt;&lt; '  ';</strong> end ; _buf &lt;&lt; '
    379. 

  379. '; _buf &lt;&lt; '&lt;/ul&gt;
    380. 

  380. ';
    381. 

  381. _buf.to_s
    382. 

  382. ----- result ----------
    383. 

  383. &lt;ul&gt;
    384. 

  384.   
    385. 

  385.   &lt;li&gt;
    386. 

  386.     aaa
    387. 

  387.   &lt;/li&gt;
    388. 

  388.   
    389. 

  389.   &lt;li&gt;
    390. 

  390.     bbb
    391. 

  391.   &lt;/li&gt;
    392. 

  392.   
    393. 

  393.   &lt;li&gt;
    394. 

  394.     ccc
    395. 

  395.   &lt;/li&gt;
    396. 

  396.   
    397. 

  397. &lt;/ul&gt;
    398. 

  398. </pre>
    399. 

  399. <br>
    400. 

  400. 

  401. 

  402. <a name="tut-escape"></a>
    403. 

  403. <h3 class="section2">Escape</h3>
    404. 

  404. <p>Erubis has ability to escape (sanitize) expression.
    405. 

  405. Erubis::Eruby class act as the following:
    406. 

  406. </p>
    407. 

  407. <ul type="disc">
    408. 

  408. <li><code>&lt;%= <em>expr</em> %&gt;</code> -  not escaped.
    409. 

  409. </li>
    410. 

  410. <li><code>&lt;%== <em>expr</em> %&gt;</code> - escaped.
    411. 

  411. </li>
    412. 

  412. <li><code>&lt;%=== <em>expr</em> %&gt;</code> - out to $stderr.
    413. 

  413. </li>
    414. 

  414. <li><code>&lt;%==== <em>expr</em> %&gt;</code> - ignored.
    415. 

  415. </li>
    416. 

  416. </ul>
    417. 

  417. <p>Erubis::EscapedEruby<sup>(<a href="#fnref:1" name="fnlink:1">*1</a>)</sup> class handle '&lt;%= %&gt;' as escaped and '&lt;%== %&gt;' as not escaped.
    418. 

  418. It means that using Erubis::EscapedEruby you can escape expression by default.
    419. 

  419. Also Erubis::XmlEruby class (which is equivalent to Erubis::EscapedEruby) is provided for compatibility with Erubis 1.1.
    420. 

  420. </p>
    421. 

  421. <a name="example3.eruby"></a>
    422. 

  422. <div class="program_caption">
    423. 

  423. example3.eruby</div>
    424. 

  424. <pre class="program">&lt;% for item in list %&gt;
    425. 

  425.   &lt;p&gt;<strong>&lt;%=</strong> item <strong>%&gt;</strong>&lt;/p&gt;
    426. 

  426.   &lt;p&gt;<strong>&lt;%==</strong> item <strong>%&gt;</strong>&lt;/p&gt;
    427. 

  427.   &lt;p&gt;<strong>&lt;%===</strong> item <strong>%&gt;</strong>&lt;/p&gt;
    428. 

  428. 

  429. &lt;% end %&gt;
    430. 

  430. </pre>
    431. 

  431. <a name="example3.rb"></a>
    432. 

  432. <div class="program_caption">
    433. 

  433. example3.rb</div>
    434. 

  434. <pre class="program">require 'erubis'
    435. 

  435. input = File.read('example3.eruby')
    436. 

  436. eruby = Erubis::<strong>EscapedEruby</strong>.new(input)    # or Erubis::XmlEruby
    437. 

  437. 

  438. puts "----- script source ---"
    439. 

  439. puts eruby.src                             # print script source
    440. 

  440. 

  441. puts "----- result ----------"
    442. 

  442. <strong>list = ['&lt;aaa&gt;', 'b&amp;b', '"ccc"']</strong>
    443. 

  443. puts eruby.result(binding())               # get result
    444. 

  444. </pre>
    445. 

  445. <a name="example3.result.split_filter"></a>
    446. 

  446. <div class="terminal_caption">
    447. 

  447. output</div>
    448. 

  448. <pre class="terminal">$ ruby example3.rb 2&gt; stderr.log
    449. 

  449. ----- script source ---
    450. 

  450. _buf = ''; for item in list 
    451. 

  451.  _buf &lt;&lt; '  &lt;p&gt;'; <strong>_buf &lt;&lt; Erubis::XmlHelper.escape_xml( item )</strong>; _buf &lt;&lt; '&lt;/p&gt;
    452. 

  452.   &lt;p&gt;'; <strong>_buf &lt;&lt; ( item ).to_s</strong>; _buf &lt;&lt; '&lt;/p&gt;
    453. 

  453.   &lt;p&gt;'; <strong>$stderr.puts("*** debug: item=#{(item).inspect}")</strong>; _buf &lt;&lt; '&lt;/p&gt;
    454. 

  454. 

  455. '; end 
    456. 

  456. _buf.to_s
    457. 

  457. ----- result ----------
    458. 

  458.   &lt;p&gt;<strong>&amp;lt;aaa&amp;gt;</strong>&lt;/p&gt;
    459. 

  459.   &lt;p&gt;&lt;aaa&gt;&lt;/p&gt;
    460. 

  460.   &lt;p&gt;&lt;/p&gt;
    461. 

  461. 

  462.   &lt;p&gt;<strong>b&amp;amp;b</strong>&lt;/p&gt;
    463. 

  463.   &lt;p&gt;b&amp;b&lt;/p&gt;
    464. 

  464.   &lt;p&gt;&lt;/p&gt;
    465. 

  465. 

  466.   &lt;p&gt;<strong>&amp;quot;ccc&amp;quot;</strong>&lt;/p&gt;
    467. 

  467.   &lt;p&gt;"ccc"&lt;/p&gt;
    468. 

  468.   &lt;p&gt;&lt;/p&gt;
    469. 

  469. 

  470. $ cat stderr.log
    471. 

  471. *** debug: item="&lt;aaa&gt;"
    472. 

  472. *** debug: item="b&amp;b"
    473. 

  473. *** debug: item="\"ccc\""
    474. 

  474. </pre>
    475. 

  475. <p>The command-line option '-e' will do the same action as Erubis::EscapedEruby.
    476. 

  476. This option is available for any language.
    477. 

  477. </p>
    478. 

  478. <a name="example3_e.result"></a>
    479. 

  479. <pre class="terminal">$ erubis -l ruby <strong>-e</strong> example3.eruby
    480. 

  480. _buf = ''; for item in list 
    481. 

  481.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    482. 

  482.   &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    483. 

  483.   &lt;p&gt;'; $stderr.puts("*** debug: item=#{(item).inspect}"); _buf &lt;&lt; '&lt;/p&gt;
    484. 

  484. 

  485. '; end 
    486. 

  486. _buf.to_s
    487. 

  487. </pre>
    488. 

  488. <p>Escaping function (default 'Erubis::XmlHelper.escape_xml()') can be changed by command-line property '--escapefunc=xxx' or by overriding Erubis::Eruby#escaped_expr() in subclass.
    489. 

  489. </p>
    490. 

  490. <div class="program_caption">
    491. 

  491. example to override Erubis::Eruby#escaped_expr()</div>
    492. 

  492. <pre class="program">class CGIEruby &lt; Erubis::Eruby
    493. 

  493.   def <strong>escaped_expr(code)</strong>
    494. 

  494.     return "CGI.escapeHTML((#{code.strip}).to_s)"
    495. 

  495.     #return "h(#{code.strip})"
    496. 

  496.   end
    497. 

  497. end
    498. 

  498. 

  499. class LatexEruby &lt; Erubi::Eruby
    500. 

  500.   def <strong>escaped_expr(code)</strong>
    501. 

  501.     return "(#{code}).gsub(/[%\\]/,'\\\\\&amp;')"
    502. 

  502.   end
    503. 

  503. end
    504. 

  504. </pre>
    505. 

  505. <div class="footnote">
    506. 

  506.  <dl compact>
    507. 

  507.   <dt>(<a name="fnref:1" href="#fnlink:1">*1</a>)</dt>
    508. 

  508.   <dd>Erubis::EscapedEruby class includes Erubis::EscapeEnhancer which swtches the action of '&lt;%= %&gt;' and '&lt;%== %&gt;'.</dd>
    509. 

  509.  </dl>
    510. 

  510. </div>
    511. 

  511. <br>
    512. 

  512. 

  513. 

  514. <a name="tut-pattern"></a>
    515. 

  515. <h3 class="section2">Embedded Pattern</h3>
    516. 

  516. <p>You can change embedded pattern '<code>&lt;% %&gt;</code>' to another by command-line option '-p' or option '<code>:pattern=&gt;...</code>' of Erubis::Eruby.new().
    517. 

  517. </p>
    518. 

  518. <a name="example4.eruby"></a>
    519. 

  519. <div class="program_caption">
    520. 

  520. example4.eruby</div>
    521. 

  521. <pre class="program"><strong>&lt;!--%</strong> for item in list <strong>%--&gt;</strong>
    522. 

  522.   &lt;p&gt;<strong>&lt;!--%=</strong> item <strong>%--&gt;</strong>&lt;/p&gt;
    523. 

  523. <strong>&lt;!--%</strong> end <strong>%--&gt;</strong>
    524. 

  524. </pre>
    525. 

  525. <a name="example4_x.result"></a>
    526. 

  526. <div class="terminal_caption">
    527. 

  527. compiled source code with command-line option '-p'</div>
    528. 

  528. <pre class="terminal">$ erubis -x <strong>-p '&lt;!--% %--&gt;'</strong> example4.eruby
    529. 

  529. _buf = ''; for item in list 
    530. 

  530.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    531. 

  531. '; end 
    532. 

  532. _buf.to_s
    533. 

  533. </pre>
    534. 

  534. <a name="example4.rb"></a>
    535. 

  535. <div class="program_caption">
    536. 

  536. example4.rb</div>
    537. 

  537. <pre class="program">require 'erubis'
    538. 

  538. input = File.read('example4.eruby')
    539. 

  539. eruby = Erubis::Eruby.new(input<strong>, :pattern=&gt;'&lt;!--% %--&gt;'</strong>)
    540. 

  540.                                       # or '&lt;(?:!--)?% %(?:--)?&gt;'
    541. 

  541. 

  542. puts "---------- script source ---"
    543. 

  543. puts eruby.src                            # print script source
    544. 

  544. 

  545. puts "---------- result ----------"
    546. 

  546. list = ['aaa', 'bbb', 'ccc']
    547. 

  547. puts eruby.result(binding())              # get result
    548. 

  548. </pre>
    549. 

  549. <a name="example4.result"></a>
    550. 

  550. <div class="terminal_caption">
    551. 

  551. output</div>
    552. 

  552. <pre class="terminal">$ ruby example4.rb
    553. 

  553. ---------- script source ---
    554. 

  554. _buf = ''; for item in list 
    555. 

  555.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    556. 

  556. '; end 
    557. 

  557. _buf.to_s
    558. 

  558. ---------- result ----------
    559. 

  559.   &lt;p&gt;aaa&lt;/p&gt;
    560. 

  560.   &lt;p&gt;bbb&lt;/p&gt;
    561. 

  561.   &lt;p&gt;ccc&lt;/p&gt;
    562. 

  562. </pre>
    563. 

  563. <p>It is able to specify regular expression with :pattern option.
    564. 

  564. Notice that you must use '<code>(?: )</code>' instead of '<code>( )</code>' for grouping.
    565. 

  565. For example, '<code>&lt;(!--)?% %(--)?&gt;</code>' will not work while '<code>&lt;(?:!--)?% %(?:--)?&gt;</code>' will work.
    566. 

  566. </p>
    567. 

  567. <br>
    568. 

  568. 

  569. 

  570. <a name="tut-context"></a>
    571. 

  571. <h3 class="section2">Context Object</h3>
    572. 

  572. <p>Context object is a set of data which are used in eRuby script.
    573. 

  573. Using context object makes clear which data to be used.
    574. 

  574. In Erubis, Hash object and Erubis::Context object are available as context object.
    575. 

  575. </p>
    576. 

  576. <p>Context data can be accessible via instance variables in eRuby script.
    577. 

  577. </p>
    578. 

  578. <a name="example5.eruby"></a>
    579. 

  579. <div class="program_caption">
    580. 

  580. example5.eruby</div>
    581. 

  581. <pre class="program">&lt;span&gt;&lt;%= <strong>@val</strong> %&gt;&lt;/span&gt;
    582. 

  582. &lt;ul&gt;
    583. 

  583.  &lt;% for item in <strong>@list</strong> %&gt;
    584. 

  584.   &lt;li&gt;&lt;%= item %&gt;&lt;/li&gt;
    585. 

  585.  &lt;% end %&gt;
    586. 

  586. &lt;/ul&gt;
    587. 

  587. </pre>
    588. 

  588. <a name="example5.rb"></a>
    589. 

  589. <div class="program_caption">
    590. 

  590. example5.rb</div>
    591. 

  591. <pre class="program">require 'erubis'
    592. 

  592. input = File.read('example5.eruby')
    593. 

  593. eruby = Erubis::Eruby.new(input)      # create Eruby object
    594. 

  594. 

  595. ## create context object
    596. 

  596. ## (key means var name, which may be string or symbol.)
    597. 

  597. <strong>context = {
    598. 

  598.   :val   =&gt; 'Erubis Example',
    599. 

  599.   'list' =&gt; ['aaa', 'bbb', 'ccc'],
    600. 

  600. }</strong>
    601. 

  601. ## or
    602. 

  602. # context = Erubis::Context.new()
    603. 

  603. # context['val'] = 'Erubis Example'
    604. 

  604. # context[:list] = ['aaa', 'bbb', 'ccc'],
    605. 

  605. 

  606. puts <strong>eruby.evaluate(context)</strong>         # get result
    607. 

  607. </pre>
    608. 

  608. <a name="example5.result"></a>
    609. 

  609. <div class="terminal_caption">
    610. 

  610. output</div>
    611. 

  611. <pre class="terminal">$ ruby example5.rb
    612. 

  612. &lt;span&gt;Erubis Example&lt;/span&gt;
    613. 

  613. &lt;ul&gt;
    614. 

  614.   &lt;li&gt;aaa&lt;/li&gt;
    615. 

  615.   &lt;li&gt;bbb&lt;/li&gt;
    616. 

  616.   &lt;li&gt;ccc&lt;/li&gt;
    617. 

  617. &lt;/ul&gt;
    618. 

  618. </pre>
    619. 

  619. <p>The difference between Erubis#result(binding) and Erubis#evaluate(context) is that the former invokes 'eval @src, binding' and the latter invokes 'context.instance_eval @src'.
    620. 

  620. This means that data is passed into eRuby script via local variables when Eruby::binding() is called, or passed via instance variables when Eruby::evaluate() is called.
    621. 

  621. </p>
    622. 

  622. <p>Here is the definition of Erubis#result() and Erubis#evaluate().
    623. 

  623. </p>
    624. 

  624. <div class="program_caption">
    625. 

  625. definition of result(binding) and evaluate(context)</div>
    626. 

  626. <pre class="program">def result(_binding=TOPLEVEL_BINDING)
    627. 

  627.   if _binding.is_a?(Hash)
    628. 

  628.     # load hash data as local variable
    629. 

  629.     _h = _binding
    630. 

  630.     _binding = binding()
    631. 

  631.     eval _h.collect{|k,v| "#{k} = _h[#{k.inspect}];"}.join, _binding
    632. 

  632.   end
    633. 

  633.   return <strong>eval(@src, _binding)</strong>
    634. 

  634. end
    635. 

  635. 

  636. def evaluate(_context=Erubis::Context.new)
    637. 

  637.   if _context.is_a?(Hash)
    638. 

  638.     # convert hash object to Context object
    639. 

  639.     _hash = _context
    640. 

  640.     _context = Erubis::Context.new
    641. 

  641.     _hash.each {|k, v| _context[k] = v }
    642. 

  642.   end
    643. 

  643.   return <strong>_context.instance_eval(@src)</strong>
    644. 

  644. end
    645. 

  645. </pre>
    646. 

  646. <p>instance_eval() is defined at Object class so it is able to use any object as a context object as well as Hash or Erubis::Context.
    647. 

  647. </p>
    648. 

  648. <a name="example6.rb"></a>
    649. 

  649. <div class="program_caption">
    650. 

  650. example6.rb</div>
    651. 

  651. <pre class="program">class MyData
    652. 

  652.   attr_accessor :val, :list
    653. 

  653. end
    654. 

  654. 

  655. ## any object can be a context object
    656. 

  656. <strong>mydata = MyData.new</strong>
    657. 

  657. <strong>mydata.val = 'Erubis Example'</strong>
    658. 

  658. <strong>mydata.list = ['aaa', 'bbb', 'ccc']</strong>
    659. 

  659. 

  660. require 'erubis'
    661. 

  661. eruby = Erubis::Eruby.new(File.read('example5.eruby'))
    662. 

  662. puts eruby.evaluate(<strong>mydata</strong>)
    663. 

  663. </pre>
    664. 

  664. <a name="example6.result"></a>
    665. 

  665. <div class="terminal_caption">
    666. 

  666. output</div>
    667. 

  667. <pre class="terminal">$ ruby example6.rb
    668. 

  668. &lt;span&gt;Erubis Example&lt;/span&gt;
    669. 

  669. &lt;ul&gt;
    670. 

  670.   &lt;li&gt;aaa&lt;/li&gt;
    671. 

  671.   &lt;li&gt;bbb&lt;/li&gt;
    672. 

  672.   &lt;li&gt;ccc&lt;/li&gt;
    673. 

  673. &lt;/ul&gt;
    674. 

  674. </pre>
    675. 

  675. <p>It is recommended to use 'Erubis::Eruby#evaluate(context)' rather than 'Erubis::Eruby#result(binding())' because the latter has some problems.
    676. 

  676. See <a href="#topics-context-vs-binding">evaluate(context) v.s. result(binding)</a> section for details.
    677. 

  677. </p>
    678. 

  678. <br>
    679. 

  679. 

  680. 

  681. <a name="tut-datafile"></a>
    682. 

  682. <h3 class="section2">Context Data File</h3>
    683. 

  683. <p>Command-line option '-f' specifies context data file.
    684. 

  684. Erubis load context data file and use it as context data.
    685. 

  685. Context data file can be YAML file ('*.yaml' or '*.yml') or Ruby script ('*.rb').
    686. 

  686. </p>
    687. 

  687. <a name="example7.eruby"></a>
    688. 

  688. <div class="program_caption">
    689. 

  689. example7.eruby</div>
    690. 

  690. <pre class="program">&lt;h1&gt;&lt;%= <strong>@title</strong> %&gt;&lt;/h1&gt;
    691. 

  691. &lt;ul&gt;
    692. 

  692.  &lt;% for user in <strong>@users</strong> %&gt;
    693. 

  693.   &lt;li&gt;
    694. 

  694.     &lt;a href="mailto:&lt;%= user['mail']%&gt;"&gt;&lt;%= user['name'] %&gt;&lt;/a&gt;
    695. 

  695.   &lt;/li&gt;
    696. 

  696.  &lt;% end %&gt;
    697. 

  697. &lt;/ul&gt;
    698. 

  698. </pre>
    699. 

  699. <a name="context.yaml"></a>
    700. 

  700. <div class="program_caption">
    701. 

  701. context.yaml</div>
    702. 

  702. <pre class="program"><strong>title:</strong> Users List
    703. 

  703. <strong>users:</strong>
    704. 

  704.   - name:  foo
    705. 

  705.     mail:  foo@mail.com
    706. 

  706.   - name:  bar
    707. 

  707.     mail:  bar@mail.net
    708. 

  708.   - name:  baz
    709. 

  709.     mail:  baz@mail.org
    710. 

  710. </pre>
    711. 

  711. <a name="context.rb"></a>
    712. 

  712. <div class="program_caption">
    713. 

  713. context.rb</div>
    714. 

  714. <pre class="program">@title = 'Users List'
    715. 

  715. @users = [
    716. 

  716.    { 'name'=&gt;'foo', 'mail'=&gt;'foo@mail.com' },
    717. 

  717.    { 'name'=&gt;'bar', 'mail'=&gt;'bar@mail.net' },
    718. 

  718.    { 'name'=&gt;'baz', 'mail'=&gt;'baz@mail.org' },
    719. 

  719. ]
    720. 

  720. </pre>
    721. 

  721. <a name="example7.result.split_filter"></a>
    722. 

  722. <div class="terminal_caption">
    723. 

  723. example of command-line option '-f'</div>
    724. 

  724. <pre class="terminal">$ erubis <strong>-f context.yaml</strong> example7.eruby
    725. 

  725. &lt;h1&gt;Users List&lt;/h1&gt;
    726. 

  726. &lt;ul&gt;
    727. 

  727.   &lt;li&gt;
    728. 

  728.     &lt;a href="mailto:foo@mail.com"&gt;foo&lt;/a&gt;
    729. 

  729.   &lt;/li&gt;
    730. 

  730.   &lt;li&gt;
    731. 

  731.     &lt;a href="mailto:bar@mail.net"&gt;bar&lt;/a&gt;
    732. 

  732.   &lt;/li&gt;
    733. 

  733.   &lt;li&gt;
    734. 

  734.     &lt;a href="mailto:baz@mail.org"&gt;baz&lt;/a&gt;
    735. 

  735.   &lt;/li&gt;
    736. 

  736. &lt;/ul&gt;
    737. 

  737. $ erubis <strong>-f context.rb</strong> example7.eruby
    738. 

  738. &lt;h1&gt;Users List&lt;/h1&gt;
    739. 

  739. &lt;ul&gt;
    740. 

  740.   &lt;li&gt;
    741. 

  741.     &lt;a href="mailto:foo@mail.com"&gt;foo&lt;/a&gt;
    742. 

  742.   &lt;/li&gt;
    743. 

  743.   &lt;li&gt;
    744. 

  744.     &lt;a href="mailto:bar@mail.net"&gt;bar&lt;/a&gt;
    745. 

  745.   &lt;/li&gt;
    746. 

  746.   &lt;li&gt;
    747. 

  747.     &lt;a href="mailto:baz@mail.org"&gt;baz&lt;/a&gt;
    748. 

  748.   &lt;/li&gt;
    749. 

  749. &lt;/ul&gt;
    750. 

  750. </pre>
    751. 

  751. <p>Command-line option '-S' converts keys of mapping in YAML data file from string into symbol.
    752. 

  752. Command-line option '-B' invokes 'Erubis::Eruby#result(binding())' instead of 'Erubis::Eruby#evaluate(context)'.
    753. 

  753. </p>
    754. 

  754. <br>
    755. 

  755. 

  756. 

  757. <a name="tut-datastr"></a>
    758. 

  758. <h3 class="section2">Context Data String</h3>
    759. 

  759. <p>Command-line option '-c <em>str</em>' enables you to specify context data in command-line.
    760. 

  760. <em>str</em> can be YAML flow-style or Ruby code.
    761. 

  761. </p>
    762. 

  762. <a name="example8.eruby"></a>
    763. 

  763. <div class="program_caption">
    764. 

  764. example8.eruby</div>
    765. 

  765. <pre class="program">&lt;h1&gt;&lt;%= @title %&gt;&lt;/h1&gt;
    766. 

  766. &lt;ul&gt;
    767. 

  767. &lt;% for item in @list %&gt;
    768. 

  768.  &lt;li&gt;&lt;%= item %&gt;&lt;/li&gt;
    769. 

  769. &lt;% end %&gt;
    770. 

  770. &lt;/ul&gt;
    771. 

  771. </pre>
    772. 

  772. <a name="example8_yaml.result"></a>
    773. 

  773. <div class="terminal_caption">
    774. 

  774. example of YAML flow style</div>
    775. 

  775. <pre class="terminal">$ erubis <strong>-c '{title: Example, list: [AAA, BBB, CCC]}'</strong> example8.eruby
    776. 

  776. &lt;h1&gt;Example&lt;/h1&gt;
    777. 

  777. &lt;ul&gt;
    778. 

  778.  &lt;li&gt;AAA&lt;/li&gt;
    779. 

  779.  &lt;li&gt;BBB&lt;/li&gt;
    780. 

  780.  &lt;li&gt;CCC&lt;/li&gt;
    781. 

  781. &lt;/ul&gt;
    782. 

  782. </pre>
    783. 

  783. <a name="example8_ruby.result"></a>
    784. 

  784. <div class="terminal_caption">
    785. 

  785. example of Ruby code</div>
    786. 

  786. <pre class="terminal">$ erubis <strong>-c '@title="Example"; @list=%w[AAA BBB CCC]'</strong> example8.eruby
    787. 

  787. &lt;h1&gt;Example&lt;/h1&gt;
    788. 

  788. &lt;ul&gt;
    789. 

  789.  &lt;li&gt;AAA&lt;/li&gt;
    790. 

  790.  &lt;li&gt;BBB&lt;/li&gt;
    791. 

  791.  &lt;li&gt;CCC&lt;/li&gt;
    792. 

  792. &lt;/ul&gt;
    793. 

  793. </pre>
    794. 

  794. <br>
    795. 

  795. 

  796. 

  797. <a name="tut-preamble"></a>
    798. 

  798. <h3 class="section2">Preamble and Postamble</h3>
    799. 

  799. <p>The first line ('_buf = '';') in the compiled source code is called preamble
    800. 

  800. and the last line ('_buf.to_s') is called postamble.
    801. 

  801. </p>
    802. 

  802. <p>Command-line option '-b' skips the output of preamble and postamble.
    803. 

  803. </p>
    804. 

  804. <a name="example9.eruby"></a>
    805. 

  805. <div class="program_caption">
    806. 

  806. example9.eruby</div>
    807. 

  807. <pre class="program">&lt;% for item in @list %&gt;
    808. 

  808.  &lt;b&gt;&lt;%= item %&gt;&lt;/b&gt;
    809. 

  809. &lt;% end %&gt;
    810. 

  810. </pre>
    811. 

  811. <a name="example9.result.split_filter"></a>
    812. 

  812. <div class="terminal_caption">
    813. 

  813. compiled source code with and without command-line option '-b'</div>
    814. 

  814. <pre class="terminal">$ erubis -x example9.eruby
    815. 

  815. <strong>_buf = '';</strong> for item in @list 
    816. 

  816.  _buf &lt;&lt; ' &lt;b&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/b&gt;
    817. 

  817. '; end 
    818. 

  818. <strong>_buf.to_s</strong>
    819. 

  819. $ erubis -x <strong>-b</strong> example9.eruby
    820. 

  820.  for item in @list 
    821. 

  821.  _buf &lt;&lt; ' &lt;b&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/b&gt;
    822. 

  822. '; end 
    823. 

  823. </pre>
    824. 

  824. <p>Erubis::Eruby.new option '<code>:preamble=&gt;false</code>' and '<code>:postamble=&gt;false</code>' also suppress output of preamble or postamle.
    825. 

  825. </p>
    826. 

  826. <a name="example9.rb"></a>
    827. 

  827. <div class="program_caption">
    828. 

  828. example9.rb</div>
    829. 

  829. <pre class="program">require 'erubis'
    830. 

  830. input = File.read('example9.eruby')
    831. 

  831. eruby1 = Erubis::Eruby.new(input)
    832. 

  832. eruby2 = Erubis::Eruby.new(input, <strong>:preamble=&gt;false, :postamble=&gt;false</strong>)
    833. 

  833. 

  834. puts eruby1.src   # print preamble and postamble
    835. 

  835. puts "--------------"
    836. 

  836. puts eruby2.src   # don't print preamble and postamble
    837. 

  837. </pre>
    838. 

  838. <a name="example9.result"></a>
    839. 

  839. <div class="terminal_caption">
    840. 

  840. output</div>
    841. 

  841. <pre class="terminal">$ ruby example9.rb
    842. 

  842. _buf = ''; for item in @list 
    843. 

  843.  _buf &lt;&lt; ' &lt;b&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/b&gt;
    844. 

  844. '; end 
    845. 

  845. _buf.to_s
    846. 

  846. --------------
    847. 

  847.  for item in @list 
    848. 

  848.  _buf &lt;&lt; ' &lt;b&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/b&gt;
    849. 

  849. '; end 
    850. 

  850. </pre>
    851. 

  851. <br>
    852. 

  852. 

  853. 

  854. <a name="tut-pi"></a>
    855. 

  855. <h3 class="section2">Processing Instruction (PI) Converter</h3>
    856. 

  856. <p>Erubis can parse Processing Instructions (PI) as embedded pattern.
    857. 

  857. </p>
    858. 

  858. <ul type="disc">
    859. 

  859. <li>'<code>&lt;?rb <em>...</em> ?&gt;</code>' represents Ruby statement.
    860. 

  860. </li>
    861. 

  861. <li>'<code>@{<em>...</em>}@</code>' represents escaped expression value.
    862. 

  862. </li>
    863. 

  863. <li>'<code>@!{<em>...</em>}@</code>' represents normal expression value.
    864. 

  864. </li>
    865. 

  865. <li>'<code>@!!{<em>...</em>}@</code>' prints expression value to standard output.
    866. 

  866. </li>
    867. 

  867. <li>(experimental) '<code>&lt;%= <em>...</em> %&gt;</code>' is also available to print expression value.
    868. 

  868. </li>
    869. 

  869. </ul>
    870. 

  870. <p>This is more useful than basic embedded pattern ('<code>&lt;% ... &gt;</code>') because PI doesn't break XML or HTML at all.
    871. 

  871. For example the following XHTML file is well-formed and HTML validator got no errors on this example.
    872. 

  872. </p>
    873. 

  873. <a name="example10.xhtml"></a>
    874. 

  874. <div class="program_caption">
    875. 

  875. example10.xhtml</div>
    876. 

  876. <pre class="program">&lt;?xml version="1.0" ?&gt;
    877. 

  877. <strong>&lt;?rb
    878. 

  878.   lang = 'en'
    879. 

  879.   list = ['&lt;aaa&gt;', 'b&amp;b', '"ccc"']
    880. 

  880. ?&gt;</strong>
    881. 

  881. &lt;html lang="<strong>@!{lang}@</strong>"&gt;
    882. 

  882.  &lt;body&gt;
    883. 

  883.   &lt;ul&gt;
    884. 

  884.   <strong>&lt;?rb for item in list ?&gt;</strong>
    885. 

  885.    &lt;li&gt;<strong>@{item}@</strong>&lt;/li&gt;
    886. 

  886.   <strong>&lt;?rb end ?&gt;</strong>
    887. 

  887.   &lt;/ul&gt;
    888. 

  888.  &lt;/body&gt;
    889. 

  889. &lt;/html&gt;
    890. 

  890. </pre>
    891. 

  891. <p>If the command-line property '--pi=<em>name</em>' is specified, erubis command parses input with PI converter.
    892. 

  892. If <em>name</em> is omitted then the following name is used according to '-l <em>lang</em>'.
    893. 

  893. </p>
    894. 

  894. <div align="center">
    895. 

  895. <table class="table1" border="1" cellspacing="0">
    896. 

  896.  <tr class="tr1">
    897. 

  897.   <th class="th1">'-l' option</th>
    898. 

  898.   <th class="th1">PI name</th>
    899. 

  899.  </tr>
    900. 

  900.  <tr class="tr1">
    901. 

  901.   <td class="td1">-l ruby</td>
    902. 

  902.   <td class="td1">&lt;?rb ... ?&gt;</td>
    903. 

  903.  </tr>
    904. 

  904.  <tr class="tr1">
    905. 

  905.   <td class="td1">-l php</td>
    906. 

  906.   <td class="td1">&lt;?php ... ?&gt;</td>
    907. 

  907.  </tr>
    908. 

  908.  <tr class="tr1">
    909. 

  909.   <td class="td1">-l perl</td>
    910. 

  910.   <td class="td1">&lt;?perl ... ?&gt;</td>
    911. 

  911.  </tr>
    912. 

  912.  <tr class="tr1">
    913. 

  913.   <td class="td1">-l java</td>
    914. 

  914.   <td class="td1">&lt;?java ... ?&gt;</td>
    915. 

  915.  </tr>
    916. 

  916.  <tr class="tr1">
    917. 

  917.   <td class="td1">-l javascript</td>
    918. 

  918.   <td class="td1">&lt;?js ... ?&gt;</td>
    919. 

  919.  </tr>
    920. 

  920.  <tr class="tr1">
    921. 

  921.   <td class="td1">-l scheme</td>
    922. 

  922.   <td class="td1">&lt;?scheme ... ?&gt;</td>
    923. 

  923.  </tr>
    924. 

  924. </table>
    925. 

  925. </div>
    926. 

  926. <a name="example10_x.result"></a>
    927. 

  927. <div class="terminal_caption">
    928. 

  928. output</div>
    929. 

  929. <pre class="terminal">$ erubis -x <strong>--pi</strong> example10.xhtml
    930. 

  930. _buf = ''; _buf &lt;&lt; '&lt;?xml version="1.0" ?&gt;
    931. 

  931. ';
    932. 

  932.   lang = 'en'
    933. 

  933.   list = ['&lt;aaa&gt;', 'b&amp;b', '"ccc"']
    934. 

  934. 

  935.  _buf &lt;&lt; '&lt;html lang="'; _buf &lt;&lt; (lang).to_s; _buf &lt;&lt; '"&gt;
    936. 

  936.  &lt;body&gt;
    937. 

  937.   &lt;ul&gt;
    938. 

  938. ';   for item in list 
    939. 

  939.  _buf &lt;&lt; '   &lt;li&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml(item); _buf &lt;&lt; '&lt;/li&gt;
    940. 

  940. ';   end 
    941. 

  941.  _buf &lt;&lt; '  &lt;/ul&gt;
    942. 

  942.  &lt;/body&gt;
    943. 

  943. &lt;/html&gt;
    944. 

  944. ';
    945. 

  945. _buf.to_s
    946. 

  946. </pre>
    947. 

  947. <p>Expression character can be changeable by command-line property '--embchar=<em>char</em>. Default is '<code>@</code>'.
    948. 

  948. </p>
    949. 

  949. <p>Use Erubis::PI::Eruby instead of Erubis::Eruby if you want to use PI as embedded pattern.
    950. 

  950. </p>
    951. 

  951. <a name="example10.rb"></a>
    952. 

  952. <div class="program_caption">
    953. 

  953. example10.rb</div>
    954. 

  954. <pre class="program">require 'erubis'
    955. 

  955. input = File.read('example10.xhtml')
    956. 

  956. eruby = Erubis::PI::Eruby.new(input)
    957. 

  957. print eruby.src
    958. 

  958. </pre>
    959. 

  959. <a name="example10.result"></a>
    960. 

  960. <div class="terminal_caption">
    961. 

  961. output</div>
    962. 

  962. <pre class="terminal">$ ruby example10.rb
    963. 

  963. _buf = ''; _buf &lt;&lt; '&lt;?xml version="1.0" ?&gt;
    964. 

  964. ';
    965. 

  965.   lang = 'en'
    966. 

  966.   list = ['&lt;aaa&gt;', 'b&amp;b', '"ccc"']
    967. 

  967. 

  968.  _buf &lt;&lt; '&lt;html lang="'; _buf &lt;&lt; (lang).to_s; _buf &lt;&lt; '"&gt;
    969. 

  969.  &lt;body&gt;
    970. 

  970.   &lt;ul&gt;
    971. 

  971. ';   for item in list 
    972. 

  972.  _buf &lt;&lt; '   &lt;li&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml(item); _buf &lt;&lt; '&lt;/li&gt;
    973. 

  973. ';   end 
    974. 

  974.  _buf &lt;&lt; '  &lt;/ul&gt;
    975. 

  975.  &lt;/body&gt;
    976. 

  976. &lt;/html&gt;
    977. 

  977. ';
    978. 

  978. _buf.to_s
    979. 

  979. </pre>
    980. 

  980. <p><strong>(experimental)</strong> Erubis supports '&lt;%= ... %&gt;' pattern with PI pattern.
    981. 

  981. </p>
    982. 

  982. <div class="program_caption">
    983. 

  983. example of Rails view template</div>
    984. 

  984. <pre class="program">&lt;table&gt;
    985. 

  985.   &lt;tr&gt;
    986. 

  986. &lt;?rb for item in @list ?&gt;
    987. 

  987.     &lt;td&gt;@{item.id}@&lt;/td&gt;
    988. 

  988.     &lt;td&gt;@{item.name}@&lt;/td&gt;
    989. 

  989.     &lt;td&gt;
    990. 

  990.        <strong>&lt;%=</strong> link_to 'Destroy', {:action=&gt;'destroy', :id=&gt;item.id},
    991. 

  991.                        :confirm=&gt;'Are you OK?' <strong>%&gt;</strong>
    992. 

  992.     &lt;/td&gt;
    993. 

  993. &lt;?rb end ?&gt;
    994. 

  994.   &lt;/tr&gt;
    995. 

  995. &lt;/table&gt;
    996. 

  996. </pre>
    997. 

  997. <br>
    998. 

  998. 

  999. 

  1000. <a name="tut-notext"></a>
    1001. 

  1001. <h3 class="section2">Retrieve Ruby Code</h3>
    1002. 

  1002. <p>Similar to '-x', ommand-line option '-X' shows converted Ruby source code.
    1003. 

  1003. The difference between '-x' and 'X' is that the former converts text part but the latter ignores it.
    1004. 

  1004. It means that you can retrieve Ruby code from eRuby script by '-X' option.
    1005. 

  1005. </p>
    1006. 

  1006. <p>For example, see the following eRuby script.
    1007. 

  1007. This is some complex, so it is difficult to grasp the program code.
    1008. 

  1008. </p>
    1009. 

  1009. <a name="example11.rhtml"></a>
    1010. 

  1010. <div class="program_caption">
    1011. 

  1011. example11.rhtml</div>
    1012. 

  1012. <pre class="program">&lt;?xml version="1.0" encoding="UTF-8"?&gt;
    1013. 

  1013. &lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
    1014. 

  1014.           "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
    1015. 

  1015. &lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt;
    1016. 

  1016.   &lt;body&gt;
    1017. 

  1017.     &lt;h3&gt;List&lt;/h3&gt;
    1018. 

  1018.     &lt;% if @list.nil? || @list.empty? %&gt;
    1019. 

  1019.     &lt;p&gt;not found.&lt;/p&gt;
    1020. 

  1020.     &lt;% else %&gt;
    1021. 

  1021.     &lt;table&gt;
    1022. 

  1022.       &lt;tbody&gt;
    1023. 

  1023.         &lt;% @list.each_with_index do |item, i| %&gt;
    1024. 

  1024.         &lt;tr bgcolor="&lt;%= i % 2 == 0 ? '#FCC' : '#CCF' %&gt;"&gt;
    1025. 

  1025.           &lt;td&gt;&lt;%= item %&gt;&lt;/td&gt;
    1026. 

  1026.         &lt;/tr&gt;
    1027. 

  1027.         &lt;% end %&gt;
    1028. 

  1028.       &lt;/tbody&gt;
    1029. 

  1029.     &lt;/table&gt;
    1030. 

  1030.     &lt;% end %&gt;
    1031. 

  1031.   &lt;/body&gt;
    1032. 

  1032. &lt;/html&gt;
    1033. 

  1033. </pre>
    1034. 

  1034. <p>Command-line option '-X' extracts only the ruby code from eRuby script.
    1035. 

  1035. </p>
    1036. 

  1036. <a name="example11.result"></a>
    1037. 

  1037. <div class="terminal_caption">
    1038. 

  1038. result</div>
    1039. 

  1039. <pre class="terminal">$ erubis <strong>-X</strong> example11.rhtml
    1040. 

  1040. _buf = '';
    1041. 

  1041. 

  1042. 

  1043. 

  1044. 

  1045. 

  1046.      if @list.nil? || @list.empty? 
    1047. 

  1047. 

  1048.      else 
    1049. 

  1049. 

  1050. 

  1051.          @list.each_with_index do |item, i| 
    1052. 

  1052.                       _buf &lt;&lt; ( i % 2 == 0 ? '#FCC' : '#CCF' ).to_s;
    1053. 

  1053.                _buf &lt;&lt; ( item ).to_s;
    1054. 

  1054. 

  1055.          end 
    1056. 

  1056. 

  1057. 

  1058.      end 
    1059. 

  1059. 

  1060. 

  1061. _buf.to_s
    1062. 

  1062. </pre>
    1063. 

  1063. <p>Command-line option '-C' (<strong>c</strong>mpact) deletes empty lines.
    1064. 

  1064. </p>
    1065. 

  1065. <a name="example11_C.result"></a>
    1066. 

  1066. <div class="terminal_caption">
    1067. 

  1067. result</div>
    1068. 

  1068. <pre class="terminal">$ erubis <strong>-XC</strong> example11.rhtml
    1069. 

  1069. _buf = '';
    1070. 

  1070.      if @list.nil? || @list.empty? 
    1071. 

  1071.      else 
    1072. 

  1072.          @list.each_with_index do |item, i| 
    1073. 

  1073.                       _buf &lt;&lt; ( i % 2 == 0 ? '#FCC' : '#CCF' ).to_s;
    1074. 

  1074.                _buf &lt;&lt; ( item ).to_s;
    1075. 

  1075.          end 
    1076. 

  1076.      end 
    1077. 

  1077. _buf.to_s
    1078. 

  1078. </pre>
    1079. 

  1079. <p>Option '-U' (<strong>u</strong>nique) converts empty lines into a line.
    1080. 

  1080. </p>
    1081. 

  1081. <a name="example11_U.result"></a>
    1082. 

  1082. <div class="terminal_caption">
    1083. 

  1083. result</div>
    1084. 

  1084. <pre class="terminal">$ erubis <strong>-XU</strong> example11.rhtml
    1085. 

  1085. _buf = '';
    1086. 

  1086. 

  1087.      if @list.nil? || @list.empty? 
    1088. 

  1088. 

  1089.      else 
    1090. 

  1090. 

  1091.          @list.each_with_index do |item, i| 
    1092. 

  1092.                       _buf &lt;&lt; ( i % 2 == 0 ? '#FCC' : '#CCF' ).to_s;
    1093. 

  1093.                _buf &lt;&lt; ( item ).to_s;
    1094. 

  1094. 

  1095.          end 
    1096. 

  1096. 

  1097.      end 
    1098. 

  1098. 

  1099. _buf.to_s
    1100. 

  1100. </pre>
    1101. 

  1101. <p>Option '-N' (<strong>n</strong>umber) adds line number.
    1102. 

  1102. It is available with '-C' or '-U'.
    1103. 

  1103. </p>
    1104. 

  1104. <a name="example11_N.result"></a>
    1105. 

  1105. <div class="terminal_caption">
    1106. 

  1106. result</div>
    1107. 

  1107. <pre class="terminal">$ erubis <strong>-XNU</strong> example11.rhtml
    1108. 

  1108.     1:  _buf = '';
    1109. 

  1109. 

  1110.     7:       if @list.nil? || @list.empty? 
    1111. 

  1111. 

  1112.     9:       else 
    1113. 

  1113. 

  1114.    12:           @list.each_with_index do |item, i| 
    1115. 

  1115.    13:                        _buf &lt;&lt; ( i % 2 == 0 ? '#FCC' : '#CCF' ).to_s;
    1116. 

  1116.    14:                 _buf &lt;&lt; ( item ).to_s;
    1117. 

  1117. 

  1118.    16:           end 
    1119. 

  1119. 

  1120.    19:       end 
    1121. 

  1121. 

  1122.    22:  _buf.to_s
    1123. 

  1123. </pre>
    1124. 

  1124. <p>Command-line option '-X' is available with PHP script.
    1125. 

  1125. </p>
    1126. 

  1126. <a name="example11.php"></a>
    1127. 

  1127. <div class="program_caption">
    1128. 

  1128. example11.php</div>
    1129. 

  1129. <pre class="program">&lt;?xml version="1.0"?&gt;
    1130. 

  1130. &lt;html&gt;
    1131. 

  1131.   &lt;body&gt;
    1132. 

  1132.     &lt;h3&gt;List&lt;/h3&gt;
    1133. 

  1133.     &lt;?php if (!$list) { ?&gt;
    1134. 

  1134.     &lt;p&gt;not found.&lt;/p&gt;
    1135. 

  1135.     &lt;?php } else { ?&gt;
    1136. 

  1136.     &lt;table&gt;
    1137. 

  1137.       &lt;tbody&gt;
    1138. 

  1138.         &lt;?php $i = 0; ?&gt;
    1139. 

  1139.         &lt;?php foreach ($list as $item) { ?&gt;
    1140. 

  1140.         &lt;tr bgcolor="&lt;?php echo ++$i % 2 == 1 ? '#FCC' : '#CCF'; ?&gt;"&gt;
    1141. 

  1141.           &lt;td&gt;&lt;?php echo $item; ?&gt;&lt;/td&gt;
    1142. 

  1142.         &lt;/tr&gt;
    1143. 

  1143.         &lt;?php } ?&gt;
    1144. 

  1144.       &lt;/tbody&gt;
    1145. 

  1145.     &lt;/table&gt;
    1146. 

  1146.     &lt;?php } ?&gt;
    1147. 

  1147.   &lt;/body&gt;
    1148. 

  1148. &lt;/html&gt;
    1149. 

  1149. </pre>
    1150. 

  1150. <a name="example11_php.result"></a>
    1151. 

  1151. <div class="terminal_caption">
    1152. 

  1152. result</div>
    1153. 

  1153. <pre class="terminal">$ erubis -XNU <strong>-l php</strong> <strong>--pi=php</strong> --trim=false example11.php
    1154. 

  1154. 

  1155.     5:      &lt;?php if (!$list) { ?&gt;
    1156. 

  1156. 

  1157.     7:      &lt;?php } else { ?&gt;
    1158. 

  1158. 

  1159.    10:          &lt;?php $i = 0; ?&gt;
    1160. 

  1160.    11:          &lt;?php foreach ($list as $item) { ?&gt;
    1161. 

  1161.    12:                       &lt;?php echo ++$i % 2 == 1 ? '#FCC' : '#CCF'; ?&gt;
    1162. 

  1162.    13:                &lt;?php echo $item; ?&gt;
    1163. 

  1163. 

  1164.    15:          &lt;?php } ?&gt;
    1165. 

  1165. 

  1166.    18:      &lt;?php } ?&gt;
    1167. 

  1167. 

  1168. </pre>
    1169. 

  1169. <br>
    1170. 

  1170. 

  1171. 

  1172. <br>
    1173. 

  1173. 

  1174. 

  1175. <a name="enhancer"></a>
    1176. 

  1176. <h2 class="section1">Enhancer</h2>
    1177. 

  1177. <p>Enhancer is a module to add a certain feature into Erubis::Eruby class.
    1178. 

  1178. Enhancer may be language-independent or only for Erubis::Eruby class.
    1179. 

  1179. </p>
    1180. 

  1180. <p>To use enhancers, define subclass and include them.
    1181. 

  1181. The folloing is an example to use <a href="#escape-enhancer">EscapeEnhancer</a>, <a href="#percentline-enhancer">PercentLineEnhancer</a>, and <a href="#bipattern-enhancer">BiPatternEnhancer</a>.
    1182. 

  1182. </p>
    1183. 

  1183. <pre class="program">class MyEruby &lt; Erubis::Eruby
    1184. 

  1184.   include EscapeEnhancer
    1185. 

  1185.   include PercentLineEnhancer
    1186. 

  1186.   include BiPatternEnhancer
    1187. 

  1187. end
    1188. 

  1188. </pre>
    1189. 

  1189. <p>You can specify enhancers in command-line with option '-E'.
    1190. 

  1190. The following is an example to use some enhancers in command-line.
    1191. 

  1191. </p>
    1192. 

  1192. <pre class="terminal">$ erubis -xE Escape,PercentLine,BiPattern example.eruby
    1193. 

  1193. </pre>
    1194. 

  1194. <p>The following is the list of enhancers.
    1195. 

  1195. </p>
    1196. 

  1196. <dl class="dl1">
    1197. 

  1197. <dt class="dt1">
    1198. 

  1198. <a href="#escape-enhancer">EscapeEnhander</a> (language-independent)</dt>
    1199. 

  1199. <dd class="dd1">
    1200. 

  1200. 	Switch '&lt;%= %&gt;' to escaped and '&lt;%== %&gt;' to unescaped.
    1201. 

  1201. </dd>
    1202. 

  1202. <dt class="dt1">
    1203. 

  1203. <a href="#stdout-enhancer">StdoutEnhancer</a> (only for Eruby)</dt>
    1204. 

  1204. <dd class="dd1">
    1205. 

  1205. 	Use $stdout instead of array buffer.
    1206. 

  1206. </dd>
    1207. 

  1207. <dt class="dt1">
    1208. 

  1208. <a href="#printout-enhancer">PrintOutEnhancer</a> (only for Eruby)</dt>
    1209. 

  1209. <dd class="dd1">
    1210. 

  1210. 	Use "print(...)" statement insead of "_buf &lt;&lt; ...".
    1211. 

  1211. </dd>
    1212. 

  1212. <dt class="dt1">
    1213. 

  1213. <a href="#printenabled-enhancer">PrintEnabledEnhancer</a> (only for Eruby)</dt>
    1214. 

  1214. <dd class="dd1">
    1215. 

  1215. 	Enable to use print() in '&lt;% ... %&gt;'.
    1216. 

  1216. </dd>
    1217. 

  1217. <dt class="dt1">
    1218. 

  1218. <a href="#array-enhancer">ArrayEnhancer</a> (only for Eruby)</dt>
    1219. 

  1219. <dd class="dd1">
    1220. 

  1220. 	Return array of string instead of returning string.
    1221. 

  1221. </dd>
    1222. 

  1222. <dt class="dt1">
    1223. 

  1223. <a href="#arraybuffer-enhancer">ArrayBufferEnhancer</a> (only for Eruby)</dt>
    1224. 

  1224. <dd class="dd1">
    1225. 

  1225. 	Use array buffer. It is a little slower than StringBufferEnhancer.
    1226. 

  1226. </dd>
    1227. 

  1227. <dt class="dt1">
    1228. 

  1228. <a href="#stringbuffer-enhancer">StringBufferEnhancer</a> (only for Eruby)</dt>
    1229. 

  1229. <dd class="dd1">
    1230. 

  1230. 	Use string buffer. This is included in Erubis::Eruby by default.
    1231. 

  1231. </dd>
    1232. 

  1232. <dt class="dt1">
    1233. 

  1233. <a href="#erbout-enhancer">ErboutEnhancer</a> (only for Eruby)</dt>
    1234. 

  1234. <dd class="dd1">
    1235. 

  1235. 	Set '_erbout = _buf = "";' to be compatible with ERB.
    1236. 

  1236. </dd>
    1237. 

  1237. <dt class="dt1">
    1238. 

  1238. <a href="#notext-enhancer">NoTextEnhancer</a> (language-independent)</dt>
    1239. 

  1239. <dd class="dd1">
    1240. 

  1240. 	Print embedded code only and ignore normal text.
    1241. 

  1241. </dd>
    1242. 

  1242. <dt class="dt1">
    1243. 

  1243. <a href="#nocode-enhancer">NoCodeEnhancer</a> (language-independent)</dt>
    1244. 

  1244. <dd class="dd1">
    1245. 

  1245. 	Print normal text only and ignore code.
    1246. 

  1246. </dd>
    1247. 

  1247. <dt class="dt1">
    1248. 

  1248. <a href="#simplify-enhancer">SimplifyEnhancer</a> (language-independent)</dt>
    1249. 

  1249. <dd class="dd1">
    1250. 

  1250. 	Make compile faster but don't trim spaces around '&lt;% %&gt;'.
    1251. 

  1251. </dd>
    1252. 

  1252. <dt class="dt1">
    1253. 

  1253. <a href="#bipattern-enhancer">BiPatternEnhancer</a> (language-independent)</dt>
    1254. 

  1254. <dd class="dd1">
    1255. 

  1255. 	[experimental] Enable to use another embedded pattern with '&lt;% %&gt;'.
    1256. 

  1256. </dd>
    1257. 

  1257. <dt class="dt1">
    1258. 

  1258. <a href="#percentline-enhancer">PercentLineEnhancer</a> (language-independent)</dt>
    1259. 

  1259. <dd class="dd1">
    1260. 

  1260. 	Regard lines starting with '%' as Ruby code. This is for compatibility with eruby and ERB.
    1261. 

  1261. </dd>
    1262. 

  1262. <dt class="dt1">
    1263. 

  1263. <a href="#headerfooter-enhancer">HeaderFooterEnhancer</a> (language-independent)</dt>
    1264. 

  1264. <dd class="dd1">
    1265. 

  1265. 	[experimental] Enable you to add header and footer in eRuby script.
    1266. 

  1266. </dd>
    1267. 

  1267. <dt class="dt1">
    1268. 

  1268. <a href="#interpolation-enhancer">InterpolationEnhancer</a> (only for Eruby)</dt>
    1269. 

  1269. <dd class="dd1">
    1270. 

  1270. 	[experimental] convert '&lt;p&gt;&lt;%= text %&gt;&lt;/p&gt;' into '_buf &lt;&lt; %Q`&lt;p&gt;#{text}&lt;/p&gt;`'.
    1271. 

  1271. </dd>
    1272. 

  1272. <dt class="dt1">
    1273. 

  1273. <a href="#deleteindent-enhancer">DeleteIndentEnhancer</a> (language-independent)</dt>
    1274. 

  1274. <dd class="dd1">
    1275. 

  1275. 	[experimental] delete indentation of HTML file and eliminate page size.
    1276. 

  1276. </dd>
    1277. 

  1277. </dl>
    1278. 

  1278. <p>If you required 'erubis/engine/enhanced', Eruby subclasses which include each enhancers are defined.
    1279. 

  1279. For example, class BiPatternEruby includes BiPatternEnhancer.
    1280. 

  1280. </p>
    1281. 

  1281. <a name="escape-enhancer"></a>
    1282. 

  1282. <h3 class="section2">EscapeEnhancer</h3>
    1283. 

  1283. <p>EscapeEnhancer switches '&lt;%= ... %&gt;' to escaped and '&lt;%== ... %&gt;' to unescaped.
    1284. 

  1284. </p>
    1285. 

  1285. <a name="example.eruby"></a>
    1286. 

  1286. <div class="program_caption">
    1287. 

  1287. example.eruby</div>
    1288. 

  1288. <pre class="program">&lt;div&gt;
    1289. 

  1289. &lt;% for item in list %&gt;
    1290. 

  1290.   &lt;p&gt;&lt;%= item %&gt;&lt;/p&gt;
    1291. 

  1291.   &lt;p&gt;&lt;%== item %&gt;&lt;/p&gt;
    1292. 

  1292. &lt;% end %&gt;
    1293. 

  1293. &lt;/div&gt;
    1294. 

  1294. </pre>
    1295. 

  1295. <a name="escape_example.result"></a>
    1296. 

  1296. <div class="terminal_caption">
    1297. 

  1297. compiled source code</div>
    1298. 

  1298. <pre class="terminal">$ erubis -xE Escape example.eruby
    1299. 

  1299. _buf = ''; _buf &lt;&lt; '&lt;div&gt;
    1300. 

  1300. '; for item in list 
    1301. 

  1301.  _buf &lt;&lt; '  &lt;p&gt;'; <strong>_buf &lt;&lt; Erubis::XmlHelper.escape_xml( item );</strong> _buf &lt;&lt; '&lt;/p&gt;
    1302. 

  1302.   &lt;p&gt;'; <strong>_buf &lt;&lt; ( item ).to_s;</strong> _buf &lt;&lt; '&lt;/p&gt;
    1303. 

  1303. '; end 
    1304. 

  1304.  _buf &lt;&lt; '&lt;/div&gt;
    1305. 

  1305. ';
    1306. 

  1306. _buf.to_s
    1307. 

  1307. </pre>
    1308. 

  1308. <p>EscapeEnhancer is language-independent.
    1309. 

  1309. </p>
    1310. 

  1310. <br>
    1311. 

  1311. 

  1312. 

  1313. <a name="stdout-enhancer"></a>
    1314. 

  1314. <h3 class="section2">StdoutEnhancer</h3>
    1315. 

  1315. <p>StdoutEnhancer use $sdtdout instead of array buffer.
    1316. 

  1316. Therefore, you can use 'print' statement in embedded ruby code.
    1317. 

  1317. </p>
    1318. 

  1318. <a name="stdout_exmple.result"></a>
    1319. 

  1319. <div class="terminal_caption">
    1320. 

  1320. compiled source code</div>
    1321. 

  1321. <pre class="terminal">$ erubis -xE Stdout example.eruby
    1322. 

  1322. <strong>_buf = $stdout;</strong> _buf &lt;&lt; '&lt;div&gt;
    1323. 

  1323. '; for item in list 
    1324. 

  1324.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1325. 

  1325.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1326. 

  1326. '; end 
    1327. 

  1327.  _buf &lt;&lt; '&lt;/div&gt;
    1328. 

  1328. ';
    1329. 

  1329. <strong>''</strong>
    1330. 

  1330. </pre>
    1331. 

  1331. <p>StdoutEnhancer is only for Eruby.
    1332. 

  1332. </p>
    1333. 

  1333. <br>
    1334. 

  1334. 

  1335. 

  1336. <a name="printout-enhancer"></a>
    1337. 

  1337. <h3 class="section2">PrintOutEnhancer</h3>
    1338. 

  1338. <p>PrintOutEnhancer makes compiled source code to use 'print(...)' instead of '_buf &lt;&lt; ...'.
    1339. 

  1339. </p>
    1340. 

  1340. <a name="printstatement_example.result"></a>
    1341. 

  1341. <div class="terminal_caption">
    1342. 

  1342. compiled source code</div>
    1343. 

  1343. <pre class="terminal">$ erubis -xE PrintOut example.eruby
    1344. 

  1344.  <strong>print</strong> '&lt;div&gt;
    1345. 

  1345. '; for item in list 
    1346. 

  1346.  <strong>print</strong> '  &lt;p&gt;'; <strong>print</strong>(( item ).to_s); <strong>print</strong> '&lt;/p&gt;
    1347. 

  1347.   &lt;p&gt;'; <strong>print</strong> Erubis::XmlHelper.escape_xml( item ); <strong>print</strong> '&lt;/p&gt;
    1348. 

  1348. '; end 
    1349. 

  1349.  <strong>print</strong> '&lt;/div&gt;
    1350. 

  1350. ';
    1351. 

  1351. </pre>
    1352. 

  1352. <p>PrintOutEnhancer is only for Eruby.
    1353. 

  1353. </p>
    1354. 

  1354. <br>
    1355. 

  1355. 

  1356. 

  1357. <a name="printenabled-enhancer"></a>
    1358. 

  1358. <h3 class="section2">PrintEnabledEnhancer</h3>
    1359. 

  1359. <p>PrintEnabledEnhancer enables you to use print() method in '&lt;% ... %&gt;'.
    1360. 

  1360. </p>
    1361. 

  1361. <a name="printenabled-example.eruby"></a>
    1362. 

  1362. <div class="program_caption">
    1363. 

  1363. printenabled-example.eruby</div>
    1364. 

  1364. <pre class="program">&lt;% for item in @list %&gt;
    1365. 

  1365.   &lt;b&gt;<strong>&lt;% print item %&gt;</strong>&lt;/b&gt;
    1366. 

  1366. &lt;% end %&gt;
    1367. 

  1367. </pre>
    1368. 

  1368. <a name="printenabled-example.rb"></a>
    1369. 

  1369. <div class="program_caption">
    1370. 

  1370. printenabled-example.rb</div>
    1371. 

  1371. <pre class="program">require 'erubis'
    1372. 

  1372. class PrintEnabledEruby &lt; Erubis::Eruby
    1373. 

  1373.   include Erubis::PrintEnabledEnhancer
    1374. 

  1374. end
    1375. 

  1375. input = File.read('printenabled-example.eruby')
    1376. 

  1376. eruby = PrintEnabledEruby.new(input)
    1377. 

  1377. list = ['aaa', 'bbb', 'ccc']
    1378. 

  1378. print eruby.evaluate(:list=&gt;list)
    1379. 

  1379. </pre>
    1380. 

  1380. <a name="printenable_example.result"></a>
    1381. 

  1381. <div class="terminal_caption">
    1382. 

  1382. output result</div>
    1383. 

  1383. <pre class="terminal">$ ruby printenabled-example.rb
    1384. 

  1384.   &lt;b&gt;aaa&lt;/b&gt;
    1385. 

  1385.   &lt;b&gt;bbb&lt;/b&gt;
    1386. 

  1386.   &lt;b&gt;ccc&lt;/b&gt;
    1387. 

  1387. </pre>
    1388. 

  1388. <p>Notice to use Eruby#evaluate() and not to use Eruby#result(),
    1389. 

  1389. because print() method in '&lt;% ... %&gt;' invokes not Kernel#print() but PrintEnabledEnhancer#print().
    1390. 

  1390. </p>
    1391. 

  1391. <p>PrintEnabledEnhancer is only for Eruby.
    1392. 

  1392. </p>
    1393. 

  1393. <br>
    1394. 

  1394. 

  1395. 

  1396. <a name="array-enhancer"></a>
    1397. 

  1397. <h3 class="section2">ArrayEnhancer</h3>
    1398. 

  1398. <p>ArrayEnhancer makes Eruby to return an array of strings.
    1399. 

  1399. </p>
    1400. 

  1400. <a name="array_example.result"></a>
    1401. 

  1401. <div class="terminal_caption">
    1402. 

  1402. compiled source code</div>
    1403. 

  1403. <pre class="terminal">$ erubis -xE Array example.eruby
    1404. 

  1404. <strong>_buf = [];</strong> _buf &lt;&lt; '&lt;div&gt;
    1405. 

  1405. '; for item in list 
    1406. 

  1406.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1407. 

  1407.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1408. 

  1408. '; end 
    1409. 

  1409.  _buf &lt;&lt; '&lt;/div&gt;
    1410. 

  1410. ';
    1411. 

  1411. <strong>_buf</strong>
    1412. 

  1412. </pre>
    1413. 

  1413. <p>ArrayEnhancer is only for Eruby.
    1414. 

  1414. </p>
    1415. 

  1415. <br>
    1416. 

  1416. 

  1417. 

  1418. <a name="arraybuffer-enhancer"></a>
    1419. 

  1419. <h3 class="section2">ArrayBufferEnhancer</h3>
    1420. 

  1420. <p>ArrayBufferEnhancer makes Eruby to use array buffer.
    1421. 

  1421. Array buffer is a litte slower than String buffer.
    1422. 

  1422. </p>
    1423. 

  1423. <p>ArrayBufferEnhancer is only for Eruby.
    1424. 

  1424. </p>
    1425. 

  1425. <a name="arraybuffer_example.result"></a>
    1426. 

  1426. <div class="terminal_caption">
    1427. 

  1427. compiled source code</div>
    1428. 

  1428. <pre class="terminal">$ erubis -xE ArrayBuffer example.eruby
    1429. 

  1429. <strong>_buf = [];</strong> _buf &lt;&lt; '&lt;div&gt;
    1430. 

  1430. '; for item in list 
    1431. 

  1431.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1432. 

  1432.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1433. 

  1433. '; end 
    1434. 

  1434.  _buf &lt;&lt; '&lt;/div&gt;
    1435. 

  1435. ';
    1436. 

  1436. <strong>_buf.join</strong>
    1437. 

  1437. </pre>
    1438. 

  1438. <br>
    1439. 

  1439. 

  1440. 

  1441. <a name="stringbuffer-enhancer"></a>
    1442. 

  1442. <h3 class="section2">StringBufferEnhancer</h3>
    1443. 

  1443. <p>StringBufferEnhancer makes Eruby to use string buffer.
    1444. 

  1444. String buffer is a little faster than array buffer.
    1445. 

  1445. Erubis::Eruby includes this enhancer by default.
    1446. 

  1446. </p>
    1447. 

  1447. <a name="stringbuffer_example.result"></a>
    1448. 

  1448. <div class="terminal_caption">
    1449. 

  1449. compiled source code</div>
    1450. 

  1450. <pre class="terminal">$ erubis -xE StringBuffer example.eruby
    1451. 

  1451. <strong>_buf = '';</strong> _buf &lt;&lt; '&lt;div&gt;
    1452. 

  1452. '; for item in list 
    1453. 

  1453.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1454. 

  1454.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1455. 

  1455. '; end 
    1456. 

  1456.  _buf &lt;&lt; '&lt;/div&gt;
    1457. 

  1457. ';
    1458. 

  1458. <strong>_buf.to_s</strong>
    1459. 

  1459. </pre>
    1460. 

  1460. <p>StringBufferEnhancer is only for Eruby.
    1461. 

  1461. </p>
    1462. 

  1462. <br>
    1463. 

  1463. 

  1464. 

  1465. <a name="erbout-enhancer"></a>
    1466. 

  1466. <h3 class="section2">ErboutEnhancer</h3>
    1467. 

  1467. <p>ErboutEnhancer makes Eruby to be compatible with ERB.
    1468. 

  1468. This is useful especially for Ruby on Rails.
    1469. 

  1469. </p>
    1470. 

  1470. <div class="terminal_caption">
    1471. 

  1471. compiled source code</div>
    1472. 

  1472. <pre class="terminal">$ erubis -xE Erbout example.eruby
    1473. 

  1473. <strong>_erbout = _buf = '';</strong> _buf &lt;&lt; '&lt;div&gt;
    1474. 

  1474. '; for item in list 
    1475. 

  1475.  _buf &lt;&lt; '  &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1476. 

  1476.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1477. 

  1477. '; end 
    1478. 

  1478.  _buf &lt;&lt; '&lt;/div&gt;
    1479. 

  1479. ';
    1480. 

  1480. _buf.to_s
    1481. 

  1481. </pre>
    1482. 

  1482. <p>ErboutEnhancer is only for Eruby.
    1483. 

  1483. </p>
    1484. 

  1484. <br>
    1485. 

  1485. 

  1486. 

  1487. <a name="notext-enhancer"></a>
    1488. 

  1488. <h3 class="section2">NoTextEnhancer</h3>
    1489. 

  1489. <p>NoTextEnhancer suppress output of text and prints only embedded code.
    1490. 

  1490. This is useful especially when debugging a complex eRuby script.
    1491. 

  1491. </p>
    1492. 

  1492. <a name="notext-example.eruby"></a>
    1493. 

  1493. <div class="program_caption">
    1494. 

  1494. notext-example.eruby</div>
    1495. 

  1495. <pre class="program">&lt;h3&gt;List&lt;/h3&gt;
    1496. 

  1496. &lt;% if !@list || @list.empty? %&gt;
    1497. 

  1497. &lt;p&gt;not found.&lt;/p&gt;
    1498. 

  1498. &lt;% else %&gt;
    1499. 

  1499. &lt;table&gt;
    1500. 

  1500.   &lt;tbody&gt;
    1501. 

  1501.     &lt;% @list.each_with_index do |item, i| %&gt;
    1502. 

  1502.     &lt;tr bgcolor="&lt;%= i%2 == 0 ? '#FFCCCC' : '#CCCCFF' %&gt;"&gt;
    1503. 

  1503.       &lt;td&gt;&lt;%= item %&gt;&lt;/td&gt;
    1504. 

  1504.     &lt;/tr&gt;
    1505. 

  1505.     &lt;% end %&gt;
    1506. 

  1506.   &lt;/tbody&gt;
    1507. 

  1507. &lt;/table&gt;
    1508. 

  1508. &lt;% end %&gt;
    1509. 

  1509. </pre>
    1510. 

  1510. <a name="notext_example.result"></a>
    1511. 

  1511. <div class="terminal_caption">
    1512. 

  1512. output example of NoTextEnhancer</div>
    1513. 

  1513. <pre class="terminal">$ erubis -xE NoText notext-example.eruby
    1514. 

  1514. _buf = '';
    1515. 

  1515.  if !@list || @list.empty? 
    1516. 

  1516. 

  1517.  else 
    1518. 

  1518. 

  1519. 

  1520.      @list.each_with_index do |item, i| 
    1521. 

  1521.                   _buf &lt;&lt; ( i%2 == 0 ? '#FFCCCC' : '#CCCCFF' ).to_s;
    1522. 

  1522.            _buf &lt;&lt; ( item ).to_s;
    1523. 

  1523. 

  1524.      end 
    1525. 

  1525. 

  1526. 

  1527.  end 
    1528. 

  1528. _buf.to_s
    1529. 

  1529. </pre>
    1530. 

  1530. <p>NoTextEnhancer is language-independent. It is useful even if you are PHP user, see <a href="#topics-php">this section</a>.
    1531. 

  1531. </p>
    1532. 

  1532. <br>
    1533. 

  1533. 

  1534. 

  1535. <a name="nocode-enhancer"></a>
    1536. 

  1536. <h3 class="section2">NoCodeEnhancer</h3>
    1537. 

  1537. <p>NoCodeEnhancer suppress output of embedded code and prints only normal text.
    1538. 

  1538. This is useful especially when validating HTML tags.
    1539. 

  1539. </p>
    1540. 

  1540. <a name="nocode-example.eruby"></a>
    1541. 

  1541. <div class="program_caption">
    1542. 

  1542. nocode-example.eruby</div>
    1543. 

  1543. <pre class="program">&lt;h3&gt;List&lt;/h3&gt;
    1544. 

  1544. &lt;% if !@list || @list.empty? %&gt;
    1545. 

  1545. &lt;p&gt;not found.&lt;/p&gt;
    1546. 

  1546. &lt;% else %&gt;
    1547. 

  1547. &lt;table&gt;
    1548. 

  1548.   &lt;tbody&gt;
    1549. 

  1549.     &lt;% @list.each_with_index do |item, i| %&gt;
    1550. 

  1550.     &lt;tr bgcolor="&lt;%= i%2 == 0 ? '#FFCCCC' : '#CCCCFF' %&gt;"&gt;
    1551. 

  1551.       &lt;td&gt;&lt;%= item %&gt;&lt;/td&gt;
    1552. 

  1552.     &lt;/tr&gt;
    1553. 

  1553.     &lt;% end %&gt;
    1554. 

  1554.   &lt;/tbody&gt;
    1555. 

  1555. &lt;/table&gt;
    1556. 

  1556. &lt;% end %&gt;
    1557. 

  1557. </pre>
    1558. 

  1558. <a name="nocode_example.result"></a>
    1559. 

  1559. <div class="terminal_caption">
    1560. 

  1560. output example of NoCodeEnhancer</div>
    1561. 

  1561. <pre class="terminal">$ erubis -xE NoCode notext-example.eruby
    1562. 

  1562. &lt;h3&gt;List&lt;/h3&gt;
    1563. 

  1563. 

  1564. &lt;p&gt;not found.&lt;/p&gt;
    1565. 

  1565. 

  1566. &lt;table&gt;
    1567. 

  1567.   &lt;tbody&gt;
    1568. 

  1568. 

  1569.     &lt;tr bgcolor=""&gt;
    1570. 

  1570.       &lt;td&gt;&lt;/td&gt;
    1571. 

  1571.     &lt;/tr&gt;
    1572. 

  1572. 

  1573.   &lt;/tbody&gt;
    1574. 

  1574. &lt;/table&gt;
    1575. 

  1575. 

  1576. </pre>
    1577. 

  1577. <p>NoCodeEnhancer is language-independent. It is useful even if you are PHP user, see <a href="#topics-php">this section</a>.
    1578. 

  1578. </p>
    1579. 

  1579. <br>
    1580. 

  1580. 

  1581. 

  1582. <a name="simplify-enhancer"></a>
    1583. 

  1583. <h3 class="section2">SimplifyEnhancer</h3>
    1584. 

  1584. <p>SimplifyEnhancer makes compiling a little faster but don't trim spaces around '&lt;% %&gt;'.
    1585. 

  1585. </p>
    1586. 

  1586. <a name="simplify_example.result"></a>
    1587. 

  1587. <div class="terminal_caption">
    1588. 

  1588. compiled source code</div>
    1589. 

  1589. <pre class="terminal">$ erubis -xE Simplify example.eruby
    1590. 

  1590. _buf = ''; _buf &lt;&lt; '&lt;div&gt;
    1591. 

  1591. '; for item in list ; _buf &lt;&lt; '
    1592. 

  1592.   &lt;p&gt;'; _buf &lt;&lt; ( item ).to_s; _buf &lt;&lt; '&lt;/p&gt;
    1593. 

  1593.   &lt;p&gt;'; _buf &lt;&lt; Erubis::XmlHelper.escape_xml( item ); _buf &lt;&lt; '&lt;/p&gt;
    1594. 

  1594. '; end ; _buf &lt;&lt; '
    1595. 

  1595. &lt;/div&gt;
    1596. 

  1596. ';
    1597. 

  1597. _buf.to_s
    1598. 

  1598. </pre>
    1599. 

  1599. <p>SimplifyEnhancer is language-independent.
    1600. 

  1600. </p>
    1601. 

  1601. <br>
    1602. 

  1602. 

  1603. 

  1604. <a name="bipattern-enhancer"></a>
    1605. 

  1605. <h3 class="section2">BiPatternEnhancer</h3>
    1606. 

  1606. <p>BiPatternEnhancer enables to use another embedded pattern with '&lt;% %&gt;'.
    1607. 

  1607. By Default, '[= ... =]' is available for expression.
    1608. 

  1608. You can specify pattern by :bipattern property.
    1609. 

  1609. </p>
    1610. 

  1610. <a name="bipattern-example.rhtml"></a>
    1611. 

  1611. <div class="program_caption">
    1612. 

  1612. bipattern-example.rhtml</div>
    1613. 

  1613. <pre class="program">&lt;% for item in list %&gt;
    1614. 

  1614.   &lt;b&gt;<strong>[= item =]</strong>&lt;/b&gt;
    1615. 

  1615.   &lt;b&gt;<strong>[== item…
    1616.

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