Defining your own elements#

An element is as simple as a PHP class which extends BaseElement, and a template to go with it (unless you want it to use the default template). After you add the class, ensure you have rebuilt your database and reload the CMS.

The getSummary() method will be used to provide a short summary to content authors of what data is in the element.

// app/src/Elements/MyElement.php
namespace App\Elements;

use DNADesign\Elemental\Models\BaseElement;

class MyElement extends BaseElement
{
    private static $singular_name = 'my element';

    private static $plural_name = 'my elements';

    private static $class_description = 'What my custom element does';

    public function getCMSFields()
    {
        $fields = parent::getCMSFields();

        // ...

        return $fields;
    }

    public function getSummary(): string
    {
        return 'String that represents element';
    }

    public function getType()
    {
        return 'My Element';
    }
}

In-line editing#

Elements can be edited in the CMS using an inline form where all your elements appear together. For elements that are more complex (e.g. use custom FormField classes) you can disable the in-line edit form by setting private static $inline_editable = false in your element class. A GridFieldDetailForm will be used to edit blocks that are not in-line editable. Alternatively as the CMS element editor is now React driven, in-line editing functionality can be added to by defining your own React components.

If in-line editing is not disabled, whilst not having a custom component defined, custom fields will not be rendered unless the field's schemaDataType is set with FormField::getSchemaDataType().

After building your own React components and including them into the CMS, altering the applicable Element's PHP definition to use the new React component can be achieved by setting some protected properties of that class.

namespace SilverStripe\ElementalBannerBlock\Form;

use SilverStripe\Forms\FormField;

class BlockLinkField extends FormField
{
    // ...
    protected $schemaDataType = FormField::SCHEMA_DATA_TYPE_CUSTOM;

    protected $schemaComponent = 'BlockLinkField';
}

[!NOTE]

• The $schemaDataType does not need to be CUSTOM, but should not be STRUCTURAL as structural types are not submitted as form data.
• The $schemaComponent is the name of the React component you have created to be used.

The above example was taken from silverstripe/elemental-bannerblock

Defining your own HTML#

MyElement will be rendered into a MyElement.ss template with the ElementHolder.ss wrapper. Changing the holder template can be done via YAML, or by using a $controller_template on your subclass.

// app/src/Elements/MyElement.php
namespace App\Elements;

use DNADesign\Elemental\Models\BaseElement;

class MyElement extends BaseElement
{
    // ...
    private static $controller_template = 'MyElementHolder';
}

To customise existing block templates such as Content and Form templates, copy the relevant files from vendor/dnadesign/silverstripe-elemental/templates to your theme. When doing this, ensure you match the folder structure (PHP class namespace) to ensure that your new template version takes priority.

Position helpers#

In your BaseElement template you can use the following variables for additional logic or styling helpers. They behave in the same way traditional SS_Viewer methods work either returning a Boolean, String or a Int

1. $First (boolean)
2. $Last (boolean)
3. $Pos (int)
4. $TotalItems (int)
5. $EvenOdd (string - 'even' or 'odd')

<div class="element element--{$EvenOdd} <% if First %>element--first<% end_if %> <% if Last %>element--last<% end_if %>">
    // ...
</div>

Style variants#

Via YAML you can configure a whitelist of style variants for each BaseElement subclass. For instance, if you have dark and light variations of your content block you would enter the following in YAML in the format (class: 'Description'). The class will be added to the ElementHolder.

DNADesign\Elemental\Models\ElementContent:
  styles:
    light: 'Light Background'
    dark: 'Dark Background'

Disabling the default stylesheets#

When installing this module, there may be a default set of CSS stylesheets that come to provide some examples for the various default element types for the front-end website.

You can disable this with YAML configuration:

# app/_config/elements.yml
DNADesign\Elemental\Controllers\ElementController:
  include_default_styles: false

Usage of gridField#

This module used to use GridField to create and update Elements in the CMS. This has now been largely succeeded by a JavaScript interface via React. However elements that are marked as being incompatible with in-line editing will still use the GridField method.