Interface craft\base\EagerLoadingFieldInterface

Extends: craft\base\SavableComponentInterface
Implemented by: craft\fields\Assets, craft\fields\BaseRelationField, craft\fields\Categories, craft\fields\Entries, craft\fields\Matrix, craft\fields\Tags, craft\fields\Users
Available since version: 3.0
Source Code: https://github.com/craftcms/cms/blob/master/src/base/EagerLoadingFieldInterface.php

EagerLoadingFieldInterface defines the common interface to be implemented by field classes.

Public Methods
Method	Description	Defined By
`afterDelete()`	Performs actions after a component is deleted.	craft\base\SavableComponentInterface
`afterSave()`	Performs actions after a component is saved.	craft\base\SavableComponentInterface
`beforeDelete()`	Performs actions before a component is deleted.	craft\base\SavableComponentInterface
`beforeSave()`	Performs actions before a component is saved.	craft\base\SavableComponentInterface
`displayName()`	Returns the display name of this class.	craft\base\ComponentInterface
`getEagerLoadingMap()`	Returns an array that maps source-to-target element IDs based on this custom field.	craft\base\EagerLoadingFieldInterface
`getIsNew()`	Returns whether the component is new (unsaved).	craft\base\SavableComponentInterface
`getSettings()`	Returns an array of the component’s settings.	craft\base\SavableComponentInterface
`getSettingsHtml()`	Returns the component’s settings HTML.	craft\base\SavableComponentInterface
`isSelectable()`	Returns whether the component should be selectable in component Type selects.	craft\base\SavableComponentInterface
`settingsAttributes()`	Returns the list of settings attribute names.	craft\base\SavableComponentInterface
`validate()`	Validates the component.	craft\base\SavableComponentInterface

Method Details

Returns an array that maps source-to-target element IDs based on this custom field.

This method aids in the eager-loading of elements when performing an element query. The returned array should contain the following keys:

elementType – the fully qualified class name of the element type that should be eager-loaded
map – an array of element ID mappings, where each element is a sub-array with source and target keys.
criteria (optional) – Any criteria parameters that should be applied to the element query when fetching the eager-loaded elements.

public abstract array, false getEagerLoadingMap ( array $sourceElements )

`$sourceElements`	craft\base\ElementInterface[]	An array of the source elements
return	array, false	The eager-loading element ID mappings, or false if no mappings exist