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Step 6 - Introduce a template

In order to display data of the Field Type from templates, you need to create and register a template for it.

Tip

See documentation about Field Type templates and about importing settings from a bundle.

In short, such a template must:

• extend EzPublishCoreBundle::content_fields.html.twig
• define a dedicated Twig block for the type, named by convention <TypeIdentifier_field>, in this case, eztweet_field
• be registered in parameters

eztweet.html.twig template

The first thing to do is create the template. It will define the default display of a tweet. Remember that Field Type templates can be overridden in order to tweak what is displayed and how.

Each Field Type template receives a set of variables that can be used to achieve the desired goal. The variable important in this case is field, an instance of eZ\Publish\API\Repository\Values\Content\Field. In addition to its own metadata (id, fieldDefIdentifier, etc.), it exposes the Field Value (Tweet\Value) through the value property.

A basic template (TweetFieldTypeBundle/Resources/views/fields/eztweet.html.twig) is:

{% block eztweet_field %}
    {% spaceless %}
        {{ field.value.contents|raw }}
    {% endspaceless %}
{% endblock %}

field.value.contents is piped through the raw twig operator, since the variable contains HTML code. Without it, the HTML markup would be visible directly, because Twig escapes variables by default. Notice that the code is nested within a spaceless tag, so that you can format the template in a readable manner without jeopardizing the display with unwanted spaces.

Using the content field helpers

Even though the above will work just fine, a few helpers will enable you to get something a bit more flexible. The EzPublishCoreBundle::content_fields.html.twig template, where the native Field Type templates are implemented, provides a few helpers: simple_block_field, simple_inline_field and field_attributes. The first two are used to display a Field either as a block or inline. field_attributes makes it easier to use the attr variable that contains additional (HTML) attributes for the field.

Let's try to display the value as a block element.

First, you need to make the template inherit from content_fields.html.twig. Then, create a field_value variable that will be used by the helper to print out the content inside the markup. The helper will use field_attributes to add the HTML attributes to the generated div.

{% extends "EzPublishCoreBundle::content_fields.html.twig" %}

{% block eztweet_field %}
    {% spaceless %}
        {% set field_value %}
            {{ field.value.contents|raw }}
        {% endset %}
        {{ block( 'simple_block_field' ) }}
    {% endspaceless %}
{% endblock %}

fieldValue is set to the markup you had above, using a {% set %} block. You then call the block function to process the simple_block_field template block.

Registering the template

As explained in the FieldType template documentation, a Field Type template needs to be registered in the eZ Platform semantic configuration.

To make sure the configuration is part of the bundle and no manual configuration is required, you need to make the bundle extend the eZ Platform semantic configuration.

To do so, you are going to make the bundle's dependency injection extension (DependencyInjection/EzSystemsTweetFieldTypeExtension.php) implement Symfony\Component\DependencyInjection\Extension\PrependExtensionInterface. This interface will let you prepend bundle configuration:

<?php

use Symfony\Component\DependencyInjection\Extension\PrependExtensionInterface;
use Symfony\Component\Yaml\Yaml;

class EzSystemsTweetFieldTypeExtension extends Extension implements PrependExtensionInterface
{
    public function prepend(ContainerBuilder $container)
    {
        $config = Yaml::parse(file_get_contents(__DIR__.'/../Resources/config/ez_field_templates.yml'));
        $container->prependExtensionConfig('ezpublish', $config);
    }
}

Next, provide the template mapping in Resources/config/ez_field_templates.yml:

system:
    default:
        field_templates:
            - {template: EzSystemsTweetFieldTypeBundle:fields:eztweet.html.twig, priority: 0}

Notice that you do not need to provide the ezpublish YAML block here. This is because you already import the configuration under the ezpublish namespace in the prepend method.