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/library/Zend/View/Helper/Navigation/HelperAbstract.php

https://bitbucket.org/hamidrezas/melobit
PHP | 855 lines | 327 code | 80 blank | 448 comment | 58 complexity | 61463f589a03c731eb823a3d97778640 MD5 | raw file
Possible License(s): AGPL-1.0
  1<?php
  2/**
  3 * Zend Framework
  4 *
  5 * LICENSE
  6 *
  7 * This source file is subject to the new BSD license that is bundled
  8 * with this package in the file LICENSE.txt.
  9 * It is also available through the world-wide-web at this URL:
 10 * http://framework.zend.com/license/new-bsd
 11 * If you did not receive a copy of the license and are unable to
 12 * obtain it through the world-wide-web, please send an email
 13 * to license@zend.com so we can send you a copy immediately.
 14 *
 15 * @category   Zend
 16 * @package    Zend_View
 17 * @subpackage Helper
 18 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 19 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 20 * @version    $Id: HelperAbstract.php 24594 2012-01-05 21:27:01Z matthew $
 21 */
 22
 23/**
 24 * @see Zend_View_Helper_Navigation_Helper
 25 */
 26require_once 'Zend/View/Helper/Navigation/Helper.php';
 27
 28/**
 29 * @see Zend_View_Helper_HtmlElement
 30 */
 31require_once 'Zend/View/Helper/HtmlElement.php';
 32
 33/**
 34 * Base class for navigational helpers
 35 *
 36 * @category   Zend
 37 * @package    Zend_View
 38 * @subpackage Helper
 39 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 40 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 41 */
 42abstract class Zend_View_Helper_Navigation_HelperAbstract
 43    extends Zend_View_Helper_HtmlElement
 44    implements Zend_View_Helper_Navigation_Helper
 45{
 46    /**
 47     * Container to operate on by default
 48     *
 49     * @var Zend_Navigation_Container
 50     */
 51    protected $_container;
 52
 53    /**
 54     * The minimum depth a page must have to be included when rendering
 55     *
 56     * @var int
 57     */
 58    protected $_minDepth;
 59
 60    /**
 61     * The maximum depth a page can have to be included when rendering
 62     *
 63     * @var int
 64     */
 65    protected $_maxDepth;
 66
 67    /**
 68     * Indentation string
 69     *
 70     * @var string
 71     */
 72    protected $_indent = '';
 73
 74    /**
 75     * Translator
 76     *
 77     * @var Zend_Translate_Adapter
 78     */
 79    protected $_translator;
 80
 81    /**
 82     * ACL to use when iterating pages
 83     *
 84     * @var Zend_Acl
 85     */
 86    protected $_acl;
 87
 88    /**
 89     * Wheter invisible items should be rendered by this helper
 90     *
 91     * @var bool
 92     */
 93    protected $_renderInvisible = false;
 94
 95    /**
 96     * ACL role to use when iterating pages
 97     *
 98     * @var string|Zend_Acl_Role_Interface
 99     */
100    protected $_role;
101
102    /**
103     * Whether translator should be used for page labels and titles
104     *
105     * @var bool
106     */
107    protected $_useTranslator = true;
108
109    /**
110     * Whether ACL should be used for filtering out pages
111     *
112     * @var bool
113     */
114    protected $_useAcl = true;
115
116    /**
117     * Default ACL to use when iterating pages if not explicitly set in the
118     * instance by calling {@link setAcl()}
119     *
120     * @var Zend_Acl
121     */
122    protected static $_defaultAcl;
123
124    /**
125     * Default ACL role to use when iterating pages if not explicitly set in the
126     * instance by calling {@link setRole()}
127     *
128     * @var string|Zend_Acl_Role_Interface
129     */
130    protected static $_defaultRole;
131
132    // Accessors:
133
134    /**
135     * Sets navigation container the helper operates on by default
136     *
137     * Implements {@link Zend_View_Helper_Navigation_Interface::setContainer()}.
138     *
139     * @param  Zend_Navigation_Container $container        [optional] container
140     *                                                     to operate on.
141     *                                                     Default is null,
142     *                                                     meaning container
143     *                                                     will be reset.
144     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
145     *                                                     returns self
146     */
147    public function setContainer(Zend_Navigation_Container $container = null)
148    {
149        $this->_container = $container;
150        return $this;
151    }
152
153    /**
154     * Returns the navigation container helper operates on by default
155     *
156     * Implements {@link Zend_View_Helper_Navigation_Interface::getContainer()}.
157     *
158     * If a helper is not explicitly set in this helper instance by calling
159     * {@link setContainer()} or by passing it through the helper entry point,
160     * this method will look in {@link Zend_Registry} for a container by using
161     * the key 'Zend_Navigation'.
162     *
163     * If no container is set, and nothing is found in Zend_Registry, a new
164     * container will be instantiated and stored in the helper.
165     *
166     * @return Zend_Navigation_Container  navigation container
167     */
168    public function getContainer()
169    {
170        if (null === $this->_container) {
171            // try to fetch from registry first
172            require_once 'Zend/Registry.php';
173            if (Zend_Registry::isRegistered('Zend_Navigation')) {
174                $nav = Zend_Registry::get('Zend_Navigation');
175                if ($nav instanceof Zend_Navigation_Container) {
176                    return $this->_container = $nav;
177                }
178            }
179
180            // nothing found in registry, create new container
181            require_once 'Zend/Navigation.php';
182            $this->_container = new Zend_Navigation();
183        }
184
185        return $this->_container;
186    }
187
188    /**
189     * Sets the minimum depth a page must have to be included when rendering
190     *
191     * @param  int $minDepth                               [optional] minimum
192     *                                                     depth. Default is
193     *                                                     null, which sets
194     *                                                     no minimum depth.
195     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
196     *                                                     returns self
197     */
198    public function setMinDepth($minDepth = null)
199    {
200        if (null === $minDepth || is_int($minDepth)) {
201            $this->_minDepth = $minDepth;
202        } else {
203            $this->_minDepth = (int) $minDepth;
204        }
205        return $this;
206    }
207
208    /**
209     * Returns minimum depth a page must have to be included when rendering
210     *
211     * @return int|null  minimum depth or null
212     */
213    public function getMinDepth()
214    {
215        if (!is_int($this->_minDepth) || $this->_minDepth < 0) {
216            return 0;
217        }
218        return $this->_minDepth;
219    }
220
221    /**
222     * Sets the maximum depth a page can have to be included when rendering
223     *
224     * @param  int $maxDepth                               [optional] maximum
225     *                                                     depth. Default is
226     *                                                     null, which sets no
227     *                                                     maximum depth.
228     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
229     *                                                     returns self
230     */
231    public function setMaxDepth($maxDepth = null)
232    {
233        if (null === $maxDepth || is_int($maxDepth)) {
234            $this->_maxDepth = $maxDepth;
235        } else {
236            $this->_maxDepth = (int) $maxDepth;
237        }
238        return $this;
239    }
240
241    /**
242     * Returns maximum depth a page can have to be included when rendering
243     *
244     * @return int|null  maximum depth or null
245     */
246    public function getMaxDepth()
247    {
248        return $this->_maxDepth;
249    }
250
251    /**
252     * Set the indentation string for using in {@link render()}, optionally a
253     * number of spaces to indent with
254     *
255     * @param  string|int $indent                          indentation string or
256     *                                                     number of spaces
257     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
258     *                                                     returns self
259     */
260    public function setIndent($indent)
261    {
262        $this->_indent = $this->_getWhitespace($indent);
263        return $this;
264    }
265
266    /**
267     * Returns indentation
268     *
269     * @return string
270     */
271    public function getIndent()
272    {
273        return $this->_indent;
274    }
275
276    /**
277     * Sets translator to use in helper
278     *
279     * Implements {@link Zend_View_Helper_Navigation_Helper::setTranslator()}.
280     *
281     * @param  mixed $translator                           [optional] translator.
282     *                                                     Expects an object of
283     *                                                     type
284     *                                                     {@link Zend_Translate_Adapter}
285     *                                                     or {@link Zend_Translate},
286     *                                                     or null. Default is
287     *                                                     null, which sets no
288     *                                                     translator.
289     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
290     *                                                     returns self
291     */
292    public function setTranslator($translator = null)
293    {
294        if (null == $translator ||
295            $translator instanceof Zend_Translate_Adapter) {
296            $this->_translator = $translator;
297        } elseif ($translator instanceof Zend_Translate) {
298            $this->_translator = $translator->getAdapter();
299        }
300
301        return $this;
302    }
303
304    /**
305     * Returns translator used in helper
306     *
307     * Implements {@link Zend_View_Helper_Navigation_Helper::getTranslator()}.
308     *
309     * @return Zend_Translate_Adapter|null  translator or null
310     */
311    public function getTranslator()
312    {
313        if (null === $this->_translator) {
314            require_once 'Zend/Registry.php';
315            if (Zend_Registry::isRegistered('Zend_Translate')) {
316                $this->setTranslator(Zend_Registry::get('Zend_Translate'));
317            }
318        }
319
320        return $this->_translator;
321    }
322
323    /**
324     * Sets ACL to use when iterating pages
325     *
326     * Implements {@link Zend_View_Helper_Navigation_Helper::setAcl()}.
327     *
328     * @param  Zend_Acl $acl                               [optional] ACL object.
329     *                                                     Default is null.
330     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
331     *                                                     returns self
332     */
333    public function setAcl(Zend_Acl $acl = null)
334    {
335        $this->_acl = $acl;
336        return $this;
337    }
338
339    /**
340     * Returns ACL or null if it isn't set using {@link setAcl()} or
341     * {@link setDefaultAcl()}
342     *
343     * Implements {@link Zend_View_Helper_Navigation_Helper::getAcl()}.
344     *
345     * @return Zend_Acl|null  ACL object or null
346     */
347    public function getAcl()
348    {
349        if ($this->_acl === null && self::$_defaultAcl !== null) {
350            return self::$_defaultAcl;
351        }
352
353        return $this->_acl;
354    }
355
356    /**
357     * Sets ACL role(s) to use when iterating pages
358     *
359     * Implements {@link Zend_View_Helper_Navigation_Helper::setRole()}.
360     *
361     * @param  mixed $role                                 [optional] role to
362     *                                                     set. Expects a string,
363     *                                                     an instance of type
364     *                                                     {@link Zend_Acl_Role_Interface},
365     *                                                     or null. Default is
366     *                                                     null, which will set
367     *                                                     no role.
368     * @throws Zend_View_Exception                         if $role is invalid
369     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
370     *                                                     returns self
371     */
372    public function setRole($role = null)
373    {
374        if (null === $role || is_string($role) ||
375            $role instanceof Zend_Acl_Role_Interface) {
376            $this->_role = $role;
377        } else {
378            require_once 'Zend/View/Exception.php';
379            $e = new Zend_View_Exception(sprintf(
380                '$role must be a string, null, or an instance of '
381                .  'Zend_Acl_Role_Interface; %s given',
382                gettype($role)
383            ));
384            $e->setView($this->view);
385            throw $e;
386        }
387
388        return $this;
389    }
390
391    /**
392     * Returns ACL role to use when iterating pages, or null if it isn't set
393     * using {@link setRole()} or {@link setDefaultRole()}
394     *
395     * Implements {@link Zend_View_Helper_Navigation_Helper::getRole()}.
396     *
397     * @return string|Zend_Acl_Role_Interface|null  role or null
398     */
399    public function getRole()
400    {
401        if ($this->_role === null && self::$_defaultRole !== null) {
402            return self::$_defaultRole;
403        }
404
405        return $this->_role;
406    }
407
408    /**
409     * Sets whether ACL should be used
410     *
411     * Implements {@link Zend_View_Helper_Navigation_Helper::setUseAcl()}.
412     *
413     * @param  bool $useAcl                                [optional] whether ACL
414     *                                                     should be used.
415     *                                                     Default is true.
416     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
417     *                                                     returns self
418     */
419    public function setUseAcl($useAcl = true)
420    {
421        $this->_useAcl = (bool) $useAcl;
422        return $this;
423    }
424
425    /**
426     * Returns whether ACL should be used
427     *
428     * Implements {@link Zend_View_Helper_Navigation_Helper::getUseAcl()}.
429     *
430     * @return bool  whether ACL should be used
431     */
432    public function getUseAcl()
433    {
434        return $this->_useAcl;
435    }
436
437    /**
438     * Return renderInvisible flag
439     *
440     * @return bool
441     */
442    public function getRenderInvisible()
443    {
444        return $this->_renderInvisible;
445    }
446
447    /**
448     * Render invisible items?
449     *
450     * @param  bool $renderInvisible                       [optional] boolean flag
451     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface
452     *                                                     returns self
453     */
454    public function setRenderInvisible($renderInvisible = true)
455    {
456        $this->_renderInvisible = (bool) $renderInvisible;
457        return $this;
458    }
459
460    /**
461     * Sets whether translator should be used
462     *
463     * Implements {@link Zend_View_Helper_Navigation_Helper::setUseTranslator()}.
464     *
465     * @param  bool $useTranslator                         [optional] whether
466     *                                                     translator should be
467     *                                                     used. Default is true.
468     * @return Zend_View_Helper_Navigation_HelperAbstract  fluent interface,
469     *                                                     returns self
470     */
471    public function setUseTranslator($useTranslator = true)
472    {
473        $this->_useTranslator = (bool) $useTranslator;
474        return $this;
475    }
476
477    /**
478     * Returns whether translator should be used
479     *
480     * Implements {@link Zend_View_Helper_Navigation_Helper::getUseTranslator()}.
481     *
482     * @return bool  whether translator should be used
483     */
484    public function getUseTranslator()
485    {
486        return $this->_useTranslator;
487    }
488
489    // Magic overloads:
490
491    /**
492     * Magic overload: Proxy calls to the navigation container
493     *
494     * @param  string $method             method name in container
495     * @param  array  $arguments          [optional] arguments to pass
496     * @return mixed                      returns what the container returns
497     * @throws Zend_Navigation_Exception  if method does not exist in container
498     */
499    public function __call($method, array $arguments = array())
500    {
501        return call_user_func_array(
502                array($this->getContainer(), $method),
503                $arguments);
504    }
505
506    /**
507     * Magic overload: Proxy to {@link render()}.
508     *
509     * This method will trigger an E_USER_ERROR if rendering the helper causes
510     * an exception to be thrown.
511     *
512     * Implements {@link Zend_View_Helper_Navigation_Helper::__toString()}.
513     *
514     * @return string
515     */
516    public function __toString()
517    {
518        try {
519            return $this->render();
520        } catch (Exception $e) {
521            $msg = get_class($e) . ': ' . $e->getMessage();
522            trigger_error($msg, E_USER_ERROR);
523            return '';
524        }
525    }
526
527    // Public methods:
528
529    /**
530     * Finds the deepest active page in the given container
531     *
532     * @param  Zend_Navigation_Container $container  container to search
533     * @param  int|null                  $minDepth   [optional] minimum depth
534     *                                               required for page to be
535     *                                               valid. Default is to use
536     *                                               {@link getMinDepth()}. A
537     *                                               null value means no minimum
538     *                                               depth required.
539     * @param  int|null                  $minDepth   [optional] maximum depth
540     *                                               a page can have to be
541     *                                               valid. Default is to use
542     *                                               {@link getMaxDepth()}. A
543     *                                               null value means no maximum
544     *                                               depth required.
545     * @return array                                 an associative array with
546     *                                               the values 'depth' and
547     *                                               'page', or an empty array
548     *                                               if not found
549     */
550    public function findActive(Zend_Navigation_Container $container,
551                               $minDepth = null,
552                               $maxDepth = -1)
553    {
554        if (!is_int($minDepth)) {
555            $minDepth = $this->getMinDepth();
556        }
557        if ((!is_int($maxDepth) || $maxDepth < 0) && null !== $maxDepth) {
558            $maxDepth = $this->getMaxDepth();
559        }
560
561        $found  = null;
562        $foundDepth = -1;
563        $iterator = new RecursiveIteratorIterator($container,
564                RecursiveIteratorIterator::CHILD_FIRST);
565
566        foreach ($iterator as $page) {
567            $currDepth = $iterator->getDepth();
568            if ($currDepth < $minDepth || !$this->accept($page)) {
569                // page is not accepted
570                continue;
571            }
572
573            if ($page->isActive(false) && $currDepth > $foundDepth) {
574                // found an active page at a deeper level than before
575                $found = $page;
576                $foundDepth = $currDepth;
577            }
578        }
579
580        if (is_int($maxDepth) && $foundDepth > $maxDepth) {
581            while ($foundDepth > $maxDepth) {
582                if (--$foundDepth < $minDepth) {
583                    $found = null;
584                    break;
585                }
586
587                $found = $found->getParent();
588                if (!$found instanceof Zend_Navigation_Page) {
589                    $found = null;
590                    break;
591                }
592            }
593        }
594
595        if ($found) {
596            return array('page' => $found, 'depth' => $foundDepth);
597        } else {
598            return array();
599        }
600    }
601
602    /**
603     * Checks if the helper has a container
604     *
605     * Implements {@link Zend_View_Helper_Navigation_Helper::hasContainer()}.
606     *
607     * @return bool  whether the helper has a container or not
608     */
609    public function hasContainer()
610    {
611        return null !== $this->_container;
612    }
613
614    /**
615     * Checks if the helper has an ACL instance
616     *
617     * Implements {@link Zend_View_Helper_Navigation_Helper::hasAcl()}.
618     *
619     * @return bool  whether the helper has a an ACL instance or not
620     */
621    public function hasAcl()
622    {
623        return null !== $this->_acl;
624    }
625
626    /**
627     * Checks if the helper has an ACL role
628     *
629     * Implements {@link Zend_View_Helper_Navigation_Helper::hasRole()}.
630     *
631     * @return bool  whether the helper has a an ACL role or not
632     */
633    public function hasRole()
634    {
635        return null !== $this->_role;
636    }
637
638    /**
639     * Checks if the helper has a translator
640     *
641     * Implements {@link Zend_View_Helper_Navigation_Helper::hasTranslator()}.
642     *
643     * @return bool  whether the helper has a translator or not
644     */
645    public function hasTranslator()
646    {
647        return null !== $this->_translator;
648    }
649
650    /**
651     * Returns an HTML string containing an 'a' element for the given page
652     *
653     * @param  Zend_Navigation_Page $page  page to generate HTML for
654     * @return string                      HTML string for the given page
655     */
656    public function htmlify(Zend_Navigation_Page $page)
657    {
658        // get label and title for translating
659        $label = $page->getLabel();
660        $title = $page->getTitle();
661
662        if ($this->getUseTranslator() && $t = $this->getTranslator()) {
663            if (is_string($label) && !empty($label)) {
664                $label = $t->translate($label);
665            }
666            if (is_string($title) && !empty($title)) {
667                $title = $t->translate($title);
668            }
669        }
670
671        // get attribs for anchor element
672        $attribs = array(
673            'id'     => $page->getId(),
674            'title'  => $title,
675            'class'  => $page->getClass(),
676            'href'   => $page->getHref(),
677            'target' => $page->getTarget()
678        );
679
680        return '<a' . $this->_htmlAttribs($attribs) . '>'
681             . $this->view->escape($label)
682             . '</a>';
683    }
684
685    // Iterator filter methods:
686
687    /**
688     * Determines whether a page should be accepted when iterating
689     *
690     * Rules:
691     * - If a page is not visible it is not accepted, unless RenderInvisible has
692     *   been set to true.
693     * - If helper has no ACL, page is accepted
694     * - If helper has ACL, but no role, page is not accepted
695     * - If helper has ACL and role:
696     *  - Page is accepted if it has no resource or privilege
697     *  - Page is accepted if ACL allows page's resource or privilege
698     * - If page is accepted by the rules above and $recursive is true, the page
699     *   will not be accepted if it is the descendant of a non-accepted page.
700     *
701     * @param  Zend_Navigation_Page $page      page to check
702     * @param  bool                $recursive  [optional] if true, page will not
703     *                                         be accepted if it is the
704     *                                         descendant of a page that is not
705     *                                         accepted. Default is true.
706     * @return bool                            whether page should be accepted
707     */
708    public function accept(Zend_Navigation_Page $page, $recursive = true)
709    {
710        // accept by default
711        $accept = true;
712
713        if (!$page->isVisible(false) && !$this->getRenderInvisible()) {
714            // don't accept invisible pages
715            $accept = false;
716        } elseif ($this->getUseAcl() && !$this->_acceptAcl($page)) {
717            // acl is not amused
718            $accept = false;
719        }
720
721        if ($accept && $recursive) {
722            $parent = $page->getParent();
723            if ($parent instanceof Zend_Navigation_Page) {
724                $accept = $this->accept($parent, true);
725            }
726        }
727
728        return $accept;
729    }
730
731    /**
732     * Determines whether a page should be accepted by ACL when iterating
733     *
734     * Rules:
735     * - If helper has no ACL, page is accepted
736     * - If page has a resource or privilege defined, page is accepted
737     *   if the ACL allows access to it using the helper's role
738     * - If page has no resource or privilege, page is accepted
739     *
740     * @param  Zend_Navigation_Page $page  page to check
741     * @return bool                        whether page is accepted by ACL
742     */
743    protected function _acceptAcl(Zend_Navigation_Page $page)
744    {
745        if (!$acl = $this->getAcl()) {
746            // no acl registered means don't use acl
747            return true;
748        }
749
750        $role = $this->getRole();
751        $resource = $page->getResource();
752        $privilege = $page->getPrivilege();
753
754        if ($resource || $privilege) {
755            // determine using helper role and page resource/privilege
756            return $acl->isAllowed($role, $resource, $privilege);
757        }
758
759        return true;
760    }
761
762    // Util methods:
763
764    /**
765     * Retrieve whitespace representation of $indent
766     *
767     * @param  int|string $indent
768     * @return string
769     */
770    protected function _getWhitespace($indent)
771    {
772        if (is_int($indent)) {
773            $indent = str_repeat(' ', $indent);
774        }
775
776        return (string) $indent;
777    }
778
779    /**
780     * Converts an associative array to a string of tag attributes.
781     *
782     * Overloads {@link Zend_View_Helper_HtmlElement::_htmlAttribs()}.
783     *
784     * @param  array $attribs  an array where each key-value pair is converted
785     *                         to an attribute name and value
786     * @return string          an attribute string
787     */
788    protected function _htmlAttribs($attribs)
789    {
790        // filter out null values and empty string values
791        foreach ($attribs as $key => $value) {
792            if ($value === null || (is_string($value) && !strlen($value))) {
793                unset($attribs[$key]);
794            }
795        }
796
797        return parent::_htmlAttribs($attribs);
798    }
799
800    /**
801     * Normalize an ID
802     *
803     * Overrides {@link Zend_View_Helper_HtmlElement::_normalizeId()}.
804     *
805     * @param  string $value
806     * @return string
807     */
808    protected function _normalizeId($value)
809    {
810        $prefix = get_class($this);
811        $prefix = strtolower(trim(substr($prefix, strrpos($prefix, '_')), '_'));
812
813        return $prefix . '-' . $value;
814    }
815
816    // Static methods:
817
818    /**
819     * Sets default ACL to use if another ACL is not explicitly set
820     *
821     * @param  Zend_Acl $acl  [optional] ACL object. Default is null, which
822     *                        sets no ACL object.
823     * @return void
824     */
825    public static function setDefaultAcl(Zend_Acl $acl = null)
826    {
827        self::$_defaultAcl = $acl;
828    }
829
830    /**
831     * Sets default ACL role(s) to use when iterating pages if not explicitly
832     * set later with {@link setRole()}
833     *
834     * @param  midex $role               [optional] role to set. Expects null,
835     *                                   string, or an instance of
836     *                                   {@link Zend_Acl_Role_Interface}.
837     *                                   Default is null, which sets no default
838     *                                   role.
839     * @throws Zend_View_Exception       if role is invalid
840     * @return void
841     */
842    public static function setDefaultRole($role = null)
843    {
844        if (null === $role ||
845            is_string($role) ||
846            $role instanceof Zend_Acl_Role_Interface) {
847            self::$_defaultRole = $role;
848        } else {
849            require_once 'Zend/View/Exception.php';
850            throw new Zend_View_Exception(
851                '$role must be null|string|Zend_Acl_Role_Interface'
852            );
853        }
854    }
855}