Title: WP_View_Config_Data::merge
Published: August 20, 2026

---

# WP_View_Config_Data::merge( array $patch, int $version ): 󠀁[WP_View_Config_Data](https://developer.wordpress.org/reference/classes/wp_view_config_data/)󠁿

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#description)
 * [Parameters](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#wp--skip-link--target)

Merges a partial configuration into the existing one.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#description)󠁿

Applies a patch of top-level keys and touches only the keys the patch names: a key
the patch omits keeps whatever it had, and a `null` value drops the key it names(
which resets it to its default). Each named key’s value is then merged into the 
current one by value shape:

 * a scalar replaces the current value;
 * an associative array merges key by key, with a nested `null` deleting just the
   leaf it names;
 * a list merges into the current list by member identity.

Identity is the member’s value cast to a string: a bare scalar is its own identity,
and a map is identified by the value of the first of the well-known identity keys(`
id`, `slug`, `field`) it carries. A member whose identity matches one already present
merges into it in place, keeping its position; a member with no identity is appended
to the end of the list.

For example, given this patch:

    ```php
    array(
      'default_view' => array( 'titleField' => 'newTitleField', 'fields' => array( 'newField' ) ),
      'default_layouts' => array( 'grid' => array( 'layout' => array( 'badgeFields' => array( 'newField' ) ) ) ),
      'view_list' => array( array( 'slug' => 'table', 'title' => 'New title' ) ),
    )
    ```

 * default_view will be updated so the titleField is ‘newTitleField’ and the newField
   is appended to the list of fields.
 * default_layouts will be updated so that newField is appended to the badgeFields.
 * view_list will be updated so that the view with slug ‘table’ has its title changed
   to ‘New title’.

A patch value only merges into a current value of the same shape: an associative
array where a list lives, or a non-empty list where an associative value lives, 
is rejected with a notice and leaves the current value unchanged. An empty array
merges nothing and is a no-op — clear a list with replace() and an empty list, or
reset a key to its default with a top-level `null`.

A patch that declares an unsupported schema version is rejected and does not change
anything.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#parameters)󠁿

 `$patch`arrayrequired

The partial configuration to merge.

`$version`intrequired

The schema version the patch was authored against.

## 󠀁[Return](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#return)󠁿

 [WP_View_Config_Data](https://developer.wordpress.org/reference/classes/wp_view_config_data/)
The instance, for chaining.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#source)󠁿

    ```php
    public function merge( array $patch, int $version ) {
    	return $this->apply( $patch, $version, __METHOD__, 'merge' );
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-view-config-data.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/class-wp-view-config-data.php#L384)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/class-wp-view-config-data.php#L384-L386)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#related)󠁿

| Uses | Description | 
| [WP_View_Config_Data::apply()](https://developer.wordpress.org/reference/classes/wp_view_config_data/apply/)`wp-includes/class-wp-view-config-data.php` |

Applies a patch to the configuration, top-level key by top-level key.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_view_config_data/merge/?output_format=md#changelog)󠁿

| Version | Description | 
| [7.1.0](https://developer.wordpress.org/reference/since/7.1.0/) | Introduced. |

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