Using Extractors to Retrieve the Seo Metadata

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Using Extractors to Retrieve the Seo Metadata¶

Instead of setting every value to the SeoMetadata manually, an extractor can do the work for you. Extractors are executed when the content object implements a specific interface. The method required by that interface will return the value for the specific SEO data. The extractor will then update the SeoMetadata object for the current object with the returned value.

Available Extractors¶

ExtractorInterface	Method	Type
`DescriptionReadInterface`	`getSeoDescription()`	Returns the meta description
`TitleReadInterface`	`getSeoTitle()`	Returns the page title
	`getTitle()`	If the document has a `getTitle()` method, it'll be used as the page title
`OriginalUrlReadInterface`	`getSeoOriginalUrl()`	Returns an absolute url to redirect to or or create a canonical link from
`OriginalRouteReadInterface`	`getSeoOriginalRoute()`	Returns a `Route` object to redirect to or create a canonical link from
`ExtrasReadInterface`	`getSeoExtras()`	Returns an associative array using `property`, `http-equiv` and `name` as keys (see below from an example).

Note

The interfaces live in the Symfony\Cmf\Bundle\SeoBundle\Extractor namespace.

An Example¶

Assume you have an Article object and you want to use both the $title and $date properties as page title and the $intro property as description, you can implement both interfaces and your result will be:

// src/AppBundle/Document/Article.php
namespace AppBundle\Document;

use Symfony\Cmf\Bundle\SeoBundle\Extractor\TitleReadInterface;
use Symfony\Cmf\Bundle\SeoBundle\Extractor\DescriptionReadInterface;
use Symfony\Cmf\Bundle\SeoBundle\Extractor\ExtrasReadInterface;

class Article implements TitleReadInterface, DescriptionReadInterface, ExtrasReadInterface
{
    protected $title;
    protected $publishDate;
    protected $intro;

    // ...
    public function getSeoTitle()
    {
        return $this->title.' ~ '.date($this->publishDate, 'm-Y');
    }

    public function getSeoDescription()
    {
        return $this->intro;
    }

    public function getSeoExtras()
    {
        return [
            'property' => [
                'og:title'       => $this->title,
                'og:description' => $this->description,
            ],
        ];
    }
}

Creating Your Own Extractor¶

To customize the extraction process, you can create your own extractor. Just create a class which implements the SeoExtractorInterface and tag it with cmf_seo.extractor:

YAML

# app/config/config.yml
services:
    extractor.custom:
        class: "AppBundle\Extractor\MyCustomExtractor"
        tags:
            - { name: cmf_seo.extractor }

XML

<!-- app/config/config.xml -->
<?xml version="1.0" ?>
<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
    <services>
        <service id="extractor.custom" class="AppBundle\Extractor\MyCustomExtractor">
            <tag name="cmf_seo.extractor"/>
        </service>
    </services>
</container>

PHP

// app/config/config.php
use AppBundle\Extractor\MyCustomExtractor;

$container->register('extractor.custom', MyCustomExtractor::class)
    ->addTag('cmf_seo.extractor')
;

This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.