/jobeet/en/14.markdown

Day 14: Feeds
=============

Yesterday, you started developing your first very own symfony application.
Don't stop now. As you learn more on symfony, try to add new features to your
application, host it somewhere, and share it with the community.

Let's move on to something completely different today.

If you are looking for a job, you will probably want to be informed as soon as
a new job is posted. Because it is not very convenient to check the website
every other hour, we will add several job feeds today to keep our Jobeet users
up-to-date.

Formats
-------

The symfony framework has native support for ~formats|Formats~ and
~mime-types|Mime Types~. This means that the same Model and Controller can
have different ~templates|Templates~ based on the requested format. The
default format is HTML but symfony supports ~several other formats|Built-in
Formats~ out of the box like `txt`, `js`, `css`, `json`, `xml`, `rdf`, or
`atom`.

The format can be set by using the `setRequestFormat()` method of the
~request|HTTP Request~ object:

    [php]
    $request->setRequestFormat('xml');

But most of the time, the format is embedded in the URL. In this case, symfony
will set it for you if the special ~`sf_format`~ variable is used in the
corresponding route. For the job list, the list URL is:

    http://jobeet.localhost/frontend_dev.php/job

This URL is equivalent to:

    http://jobeet.localhost/frontend_dev.php/job.html

Both URLs are equivalent because the routes generated by the
`sfPropelRouteCollection` class have the `sf_format` as the extension and
because `html` is the default format. You can check it for yourself by running
the `app:routes` task:

![Cli](http://www.symfony-project.org/images/jobeet/1_4/15/cli.png)

Feeds
-----

### Latest Jobs Feed

Supporting different formats is as easy as creating different templates. To
create an [Atom feed](http://en.wikipedia.org/wiki/Atom_(standard)) for the
latest jobs, create an `indexSuccess.atom.php` template:

    [php]
    <!-- apps/frontend/modules/job/templates/indexSuccess.atom.php -->
    <?xml version="1.0" encoding="utf-8"?>
    <feed xmlns="http://www.w3.org/2005/Atom">
      <title>Jobeet</title>
      <subtitle>Latest Jobs</subtitle>
      <link href="" rel="self"/>
      <link href=""/>
      <updated></updated>
      <author><name>Jobeet</name></author>
      <id>Unique Id</id>

      <entry>
        <title>Job title</title>
        <link href="" />
        <id>Unique id</id>
        <updated></updated>
        <summary>Job description</summary>
        <author><name>Company</name></author>
      </entry>
    </feed>

>**SIDEBAR**
>Template Names
>
>As `html` is the most common format used for web applications, it can be omitted
>from the template name. Both `indexSuccess.php` and `indexSuccess.html.php`
>templates are equivalent and symfony uses the first one it finds.
>
>Why are default templates suffixed with `Success`? An action can return a value
>to indicate which template to render. If the action returns nothing, it is
>equivalent to the following code:
>
>     [php]
>     return sfView::SUCCESS; // == 'Success'
>
>If you want to change the suffix, just return something else:
>
>     [php]
>     return sfView::ERROR; // == 'Error'
>
>     return 'Foo';
>
>As seen in a previous day, the name of the template can also be changed by
>using the `setTemplate()` method:
>
>     [php]
>     $this->setTemplate('foo');

By default, symfony will change the response `~Content-Type~` according to the
format, and for all non-HTML formats, the layout is disabled. For an Atom
feed, symfony changes the `Content-Type` to `application/atom+xml;
charset=utf-8`.

In the Jobeet footer, update the link to the feed:

    [php]
    <!-- apps/frontend/templates/layout.php -->
    <li class="feed">
      <a href="<?php echo url_for('@job?sf_format=atom') ?>">Full feed</a>
    </li>

The ~internal URI|Internal URI~ is the same as for the `job` list with the
`sf_format` added as a variable.

Add a `<link>` tag in the head section of the layout to allow automatic
discover by the browser of our feed:

    [php]
    <!-- apps/frontend/templates/layout.php -->
    <link rel="alternate" type="application/atom+xml" title="Latest Jobs"
      href="<?php echo url_for('@job?sf_format=atom', true) ?>" />

For the link `href` attribute, an ~URL (Absolute)~ is used thanks to the
second argument of the `url_for()` helper.

Replace the Atom template header with the following code:

    [php]
    <!-- apps/frontend/modules/job/templates/indexSuccess.atom.php -->
    <title>Jobeet</title>
    <subtitle>Latest Jobs</subtitle>
    <link href="<?php echo url_for('@job?sf_format=atom', true) ?>" rel="self"/>
    <link href="<?php echo url_for('@homepage', true) ?>"/>
<propel>
    <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', JobeetJobPeer::getLatestPost()->getCreatedAt('U')) ?></updated>
</propel>
<doctrine>
    <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', Doctrine::getTable('JobeetJob')->getLatestPost()->getDateTimeObject('created_at')->format('U')) ?></updated>
</doctrine>
    <author>
      <name>Jobeet</name>
    </author>
    <id><?php echo sha1(url_for('@job?sf_format=atom', true)) ?></id>

<propel>
Notice the usage of `U` as an argument to `getCreatedAt()` to get the date as
a timestamp. To get the date of the latest post, create the `getLatestPost()`
method:
</propel>
<doctrine>
Notice the usage of the `U` as an argument to `format()` to get the date as a
timestamp. To get the date of the latest post, create the `getLatestPost()`
method:
</doctrine>

<propel>
    [php]
    // lib/model/JobeetJobPeer.php
    class JobeetJobPeer extends BaseJobeetJobPeer
    {
      static public function getLatestPost()
      {
        $criteria = new Criteria();
        self::addActiveJobsCriteria($criteria);

        return JobeetJobPeer::doSelectOne($criteria);
      }

      // ...
    }
</propel>
<doctrine>
    [php]
    // lib/model/doctrine/JobeetJobTable.class.php
    class JobeetJobTable extends Doctrine_Table
    {
      public function getLatestPost()
      {
        $q = Doctrine_Query::create()
          ->from('JobeetJob j');
        $this->addActiveJobsQuery($q);

        return $q->fetchOne();
      }

      // ...
    }
</doctrine>

The feed entries can be generated with the following code:

    [php]
    <!-- apps/frontend/modules/job/templates/indexSuccess.atom.php -->
    <?php use_helper('Text') ?>
    <?php foreach ($categories as $category): ?>
      <?php foreach ($category->getActiveJobs(sfConfig::get('app_max_jobs_on_homepage')) as $job): ?>
        <entry>
          <title>
            <?php echo $job->getPosition() ?> (<?php echo $job->getLocation() ?>)
          </title>
          <link href="<?php echo url_for('job_show_user', $job, true) ?>" />
          <id><?php echo sha1($job->getId()) ?></id>
<propel>
          <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $job->getCreatedAt('U')) ?></updated>
</propel>
<doctrine>
          <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $job->getDateTimeObject('created_at')->format('U')) ?></updated>
</doctrine>
          <summary type="xhtml">
           <div xmlns="http://www.w3.org/1999/xhtml">
             <?php if ($job->getLogo()): ?>
               <div>
                 <a href="<?php echo $job->getUrl() ?>">
                   <img src="http://<?php echo $sf_request->getHost().'/uploads/jobs/'.$job->getLogo() ?>"
                     alt="<?php echo $job->getCompany() ?> logo" />
                 </a>
               </div>
             <?php endif; ?>

             <div>
               <?php echo simple_format_text($job->getDescription()) ?>
             </div>

             <h4>How to apply?</h4>

             <p><?php echo $job->getHowToApply() ?></p>
           </div>
          </summary>
          <author>
            <name><?php echo $job->getCompany() ?></name>
          </author>
        </entry>
      <?php endforeach; ?>
    <?php endforeach; ?>

The `getHost()` method of the request object (`$sf_request`) returns the
current host, which comes in handy for creating an absolute link for the company
logo.

![Feed](http://www.symfony-project.org/images/jobeet/1_4/15/feed.png)

>**TIP**
>When creating a feed, ~debugging|Debug~ is easier if you use command line tools like
>[`curl`](http://curl.haxx.se/) or
>[`wget`](http://www.gnu.org/software/wget/), as you see the actual content of
>the feed.

### Latest Jobs in a Category Feed

One of the goals of Jobeet is to help people find more targeted jobs. So, we
need to provide a ~feed|Feeds~ for each category.

First, let's update the `category` route to add support for different formats:

    [yml]
    // apps/frontend/config/routing.yml
    category:
      url:     /category/:slug.:sf_format
      class:   sfPropelRoute
      param:   { module: category, action: show, sf_format: html }
      options: { model: JobeetCategory, type: object }
      requirements:
        sf_format: (?:html|atom)

Now, the `category` route will understand both the `html` and `atom` formats.
Update the links to category feeds in the ~templates|Templates~:

    [php]
    <!-- apps/frontend/modules/job/templates/indexSuccess.php -->
    <div class="feed">
      <a href="<?php echo url_for('category', array('sf_subject' => $category, 'sf_format' => 'atom')) ?>">Feed</a>
    </div>

    <!-- apps/frontend/modules/category/templates/showSuccess.php -->
    <div class="feed">
      <a href="<?php echo url_for('category', array('sf_subject' => $category, 'sf_format' => 'atom')) ?>">Feed</a>
    </div>

The last step is to create the `showSuccess.atom.php` template. But as this
feed will also list jobs, we can ~refactor|Refactoring~ the code that
generates the feed entries by creating a `_list.atom.php` partial. As for the
`html` format, ~partials|Partial Templates~ are format specific:

    [php]
    <!-- apps/frontend/modules/job/templates/_list.atom.php -->
    <?php use_helper('Text') ?>

    <?php foreach ($jobs as $job): ?>
      <entry>
        <title><?php echo $job->getPosition() ?> (<?php echo $job->getLocation() ?>)</title>
        <link href="<?php echo url_for('job_show_user', $job, true) ?>" />
        <id><?php echo sha1($job->getId()) ?></id>
<propel>
          <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $job->getCreatedAt('U')) ?></updated>
</propel>
<doctrine>
          <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $job->getDateTimeObject('created_at')->format('U')) ?></updated>
</doctrine>
        <summary type="xhtml">
         <div xmlns="http://www.w3.org/1999/xhtml">
           <?php if ($job->getLogo()): ?>
             <div>
               <a href="<?php echo $job->getUrl() ?>">
                 <img src="http://<?php echo $sf_request->getHost().'/uploads/jobs/'.$job->getLogo() ?>"
                   alt="<?php echo $job->getCompany() ?> logo" />
               </a>
             </div>
           <?php endif; ?>

           <div>
             <?php echo simple_format_text($job->getDescription()) ?>
           </div>

           <h4>How to apply?</h4>

           <p><?php echo $job->getHowToApply() ?></p>
         </div>
        </summary>
        <author>
          <name><?php echo $job->getCompany() ?></name>
        </author>
      </entry>
    <?php endforeach; ?>

You can use the `_list.atom.php` partial to simplify the job feed template:

    [php]
    <!-- apps/frontend/modules/job/templates/indexSuccess.atom.php -->
    <?xml version="1.0" encoding="utf-8"?>
    <feed xmlns="http://www.w3.org/2005/Atom">
      <title>Jobeet</title>
      <subtitle>Latest Jobs</subtitle>
      <link href="<?php echo url_for('@job?sf_format=atom', true) ?>" rel="self"/>
      <link href="<?php echo url_for('@homepage', true) ?>"/>
<propel>
      <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', JobeetJobPeer::getLatestPost()->getCreatedAt('U')) ?></updated>
</propel>
<doctrine>
      <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', Doctrine::getTable('JobeetJob')->getLatestPost()->getDateTimeObject('created_at')->format('U')) ?></updated>
</doctrine>
      <author>
        <name>Jobeet</name>
      </author>
      <id><?php echo sha1(url_for('@job?sf_format=atom', true)) ?></id>

    <?php foreach ($categories as $category): ?>
      <?php include_partial('job/list', array('jobs' => $category->getActiveJobs(sfConfig::get('app_max_jobs_on_homepage')))) ?>
    <?php endforeach; ?>
    </feed>

Eventually, create the `showSuccess.atom.php` template:

    [php]
    <!-- apps/frontend/modules/category/templates/showSuccess.atom.php -->
    <?xml version="1.0" encoding="utf-8"?>
    <feed xmlns="http://www.w3.org/2005/Atom">
      <title>Jobeet (<?php echo $category ?>)</title>
      <subtitle>Latest Jobs</subtitle>
      <link href="<?php echo url_for('category', array('sf_subject' => $category, 'sf_format' => 'atom'), true) ?>" rel="self" />
      <link href="<?php echo url_for('category', array('sf_subject' => $category), true) ?>" />
<propel>
      <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $category->getLatestPost()->getCreatedAt('U')) ?></updated>
</propel>
<doctrine>
      <updated><?php echo gmstrftime('%Y-%m-%dT%H:%M:%SZ', $category->getLatestPost()->getDateTimeObject('created_at')->format('U')) ?></updated>
</doctrine>
      <author>
        <name>Jobeet</name>
      </author>
      <id><?php echo sha1(url_for('category', array('sf_subject' => $category), true)) ?></id>

      <?php include_partial('job/list', array('jobs' => $pager->getResults())) ?>
    </feed>

As for the main job feed, we need the date of the latest job for a category:

    [php]
<propel>
    // lib/model/JobeetCategory.php
</propel>
<doctrine>
    // lib/model/doctrine/JobeetCategory.class.php
</doctrine>
    class JobeetCategory extends BaseJobeetCategory
    {
      public function getLatestPost()
      {
        $jobs = $this->getActiveJobs(1);

        return $jobs[0];
      }

      // ...
    }

![Category Feed](http://www.symfony-project.org/images/jobeet/1_4/15/category_feed.png)

See you Tomorrow
----------------

As with many symfony features, the native format support allows you to add
feeds to your websites without effort.

Today, we have enhanced the job seeker experience. Tomorrow, we will see how
to provide greater exposure to the job posters by providing a Web Service.

__ORM__