Base class for managing dependencies. Extended by WP_Scripts and WP_Styles.

Source: wp-includes/class-wp-dependencies.php
Since: 2.6.0

Properties

Public Properties

Property	Type	Since	Description
$registered	_WP_Dependency[]	2.6.8	All registered items keyed by handle
$queue	string[]	2.6.8	Handles of queued items
$to_do	string[]	2.6.0	Handles pending processing
$done	string[]	2.6.0	Handles already processed
$args	array	2.6.0	Additional arguments per handle
$groups	(int|false)[]	2.8.0	Group level per handle
$group	int	2.8.0	Deprecated (4.5.0)

Private Properties

Property	Type	Since	Description
$all_queued_deps	array	5.4.0	Cache of flattened queue with dependencies
$queued_before_register	array	5.9.0	Items enqueued before registration
$dependencies_with_missing_dependencies	string[]	6.9.1	Handles with missing deps (for warning dedup)

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Methods

do_items()

Processes items and their dependencies.

public function do_items(
    string|string[]|false $handles = false,
    int|false $group = false
): string[]

Since: 2.6.0

Parameter	Type	Description
$handles	string|string[]|false	Items to process (false = queue)
$group	int|false	Group level

Returns: Array of processed handles.

Flow:

1. Resolves all dependencies via all_deps()
2. Iterates $to_do array
3. Calls do_item() for each unprocessed handle
4. Adds successful items to $done

---

do_item()

Processes a single item. Override in subclasses.

public function do_item(
    string $handle,
    int|false $group = false
): bool

Since: 2.6.0

Parameter	Type	Description
$handle	string	Item handle
$group	int|false	Group level

Returns: true if registered, false otherwise.

Note: Base implementation only checks if handle is registered. Subclasses override to output assets.

---

all_deps()

Recursively builds the dependency tree.

public function all_deps(
    string|string[] $handles,
    bool $recursion = false,
    int|false $group = false
): bool

Since: 2.1.0

Parameter	Type	Description
$handles	string|string[]	Handle(s) to resolve
$recursion	bool	Internal flag for recursive calls
$group	int|false	Group level

Returns: true on success, false on failure.

Behavior:

• Skips items already in $done
• Recursively resolves dependencies
• Handles query string args (e.g., 'handle?arg=value')
• Issues _doing_it_wrong for missing dependencies (6.9.1+)

---

add()

Registers an item.

public function add(
    string $handle,
    string|false $src,
    string[] $deps = array(),
    string|bool|null $ver = false,
    mixed $args = null
): bool

Since: 2.1.0

Parameter	Type	Description
$handle	string	Unique item name
$src	string|false	URL or false for alias
$deps	string[]	Dependency handles
$ver	string|bool|null	Version (false=default, null=none)
$args	mixed	Additional args (e.g., media type)

Returns: true if registered, false if already exists.

Note: Creates a _WP_Dependency instance stored in $registered.

---

add_data()

Adds extra data to a registered item.

public function add_data(
    string $handle,
    string $key,
    mixed $value
): bool

Since: 2.6.0

Parameter	Type	Description
$handle	string	Item handle
$key	string	Data key
$value	mixed	Data value

Returns: true on success, false if not registered.

Note: conditional key is deprecated as of 6.9.0.

---

get_data()

Gets extra data from a registered item.

public function get_data(
    string $handle,
    string $key
): mixed

Since: 3.3.0

Parameter	Type	Description
$handle	string	Item handle
$key	string	Data key

Returns: Data value or false if not found.

---

remove()

Unregisters item(s).

public function remove( string|string[] $handles ): void

Since: 2.1.0

---

enqueue()

Adds item(s) to the queue.

public function enqueue( string|string[] $handles ): void

Since: 2.1.0

Behavior:

• Parses query string args from handle
• Clears $all_queued_deps cache
• If not registered, stores in $queued_before_register for later

---

dequeue()

Removes item(s) from the queue.

public function dequeue( string|string[] $handles ): void

Since: 2.1.0

---

query()

Queries item status.

public function query(
    string $handle,
    string $status = 'registered'
): bool|_WP_Dependency

Since: 2.1.0

Parameter	Type	Description
$handle	string	Item handle
$status	string	Status to check

Status	Returns
'registered', 'scripts'	_WP_Dependency object or false
'enqueued', 'queue'	true if in queue or is dependency
'to_do', 'to_print'	true if pending
'done', 'printed'	true if processed

---

set_group()

Sets the group level for a handle.

public function set_group(
    string $handle,
    bool $recursion,
    int|false $group
): bool

Since: 2.8.0

Parameter	Type	Description
$handle	string	Item handle
$recursion	bool	Internal flag
$group	int|false	Group level

Returns: true if not already in a lower group.

Note: Items can only move to lower groups, not higher.

---

get_etag()

Generates ETag for cache validation.

public function get_etag( string[] $load ): string

Since: 6.7.0

Parameter	Type	Description
$load	string[]	Handles to include

Returns: ETag string (e.g., W/"abc123...").

Note: Uses MD5 hash of WordPress version and handle versions.

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get_dependency_warning_message() (protected)

Gets warning message for missing dependencies.

protected function get_dependency_warning_message(
    string $handle,
    string[] $missing_dependency_handles
): string

Since: 6.9.1

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recurse_deps() (protected)

Recursively searches for a handle in the dependency tree.

protected function recurse_deps(
    string[] $queue,
    string $handle
): bool

Since: 4.0.0

Parameter	Type	Description
$queue	string[]	Queued handles
$handle	string	Handle to find

Returns: true if found in dependency tree.

Note: Caches flattened result in $all_queued_deps.

---

_WP_Dependency Class

Individual dependency item stored in $registered.

Source: wp-includes/class-wp-dependency.php

Properties

Property	Type	Description
$handle	string	Unique identifier
$src	string|false	Source URL or false
$deps	string[]	Dependency handles
$ver	string|bool|null	Version
$args	mixed	Additional args
$extra	array	Extra data
$textdomain	string	Translation domain
$translations_path	string	Path to translations

Methods

public function __construct(
    string $handle,
    string|false $src,
    string[] $deps,
    string|bool|null $ver,
    mixed $args
)

public function add_data( string $key, mixed $value ): bool

public function set_translations(
    string $domain,
    string $path = ''
): bool

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Usage Example

// Get the scripts instance
$scripts = wp_scripts();

// Check what's registered
foreach ( $scripts->registered as $handle => $dep ) {
    echo "$handle: {$dep->src}n";
}

// Check queue
print_r( $scripts->queue );

// Check if processed
if ( $scripts->query( 'jquery', 'done' ) ) {
    echo "jQuery already printed";
}