Registering a source consists of defining a <strong>name</strong> for that source and a callback function specifying how to get a value from that source and pass it to a block attribute. Once a source is registered, any block that supports the Block Bindings API can use a value from that source by setting its metadata.bindings attribute to a value that refers to the source. Note that register_block_bindings_source() should be called from a handler attached to the init hook. <h2>Example</h2> <h3>Registering a source</h3> First, you need to define a function that will be used to get the value from the source. function my_plugin_get_custom_source_value( array $source_args, $block_instance, string $attribute_name ) {
// Your custom logic to get the value from the source.
// For example, you can use the $source_args to look up a value in a custom table or get it from an external API.
$value = $source_args['key'];
return "The value passed to the block is: $value"
} The $source_args will contain the arguments passed to the source in the block's metadata.bindings attribute. See the example in the "Usage in a block" section below. function my_plugin_register_block_bindings_sources() {
register_block_bindings_source( 'my-plugin/my-custom-source', array(
'label' => __( 'My Custom Source', 'my-plugin' ),
'get_value_callback' => 'my_plugin_get_custom_source_value',
) );
}
add_action( 'init', 'my_plugin_register_block_bindings_sources' ); <h3>Usage in a block</h3> In a block's metadata.bindings attribute, you can specify the source and its arguments. Such a block will use the source to override the block attribute's value. For example: <!-- wp:paragraph {
"metadata": {
"bindings": {
"content": {
"source": "my-plugin/my-custom-source",
"args": {
"key": "you can pass any custom arguments here"
}
}
}
}
} -->
<p>Fallback text that gets replaced.</p>
<!-- /wp:paragraph -->
Parameters
$source_namestring
The name of the source. It must be a string containing a namespace prefix, i.e. my-plugin/my-custom-source. It must only contain lowercase alphanumeric characters, the forward slash / and dashes.
$source_propertiesarray
The array of arguments that are used to register a source.
$labelstring
The label of the source.
$get_value_callbackcallable
A callback executed when the source is processed during block rendering. The callback should have the following signature: function( $source_args, $block_instance, $attribute_name ): mixed - @param array $source_args Array containing source arguments used to look up the override value, i.e. {"key": "foo"}. - @param WP_Block $block_instance The block instance. - @param string $attribute_name The name of an attribute. The callback has a mixed return type; it may return a string to override the block's original value, null, false to remove an attribute, etc.
$uses_contextstring[]
Optional. Array of values to add to block uses_context needed by the source.
Return
WP_Block_Bindings_Source|false
Source when the registration was successful, or false on failure.
Signature, return type and hooks compared across 5 parsed releases.
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