+<?php
+
+/**
+ * @file
+ * Documents API functions for Libraries module.
+ */
+
+/**
+ * @defgroup libraries External libraries
+ * @{
+ * External libraries are not shipped as part of contributed modules for
+ * licensing and maintenance reasons. The Libraries API module aims to solve the
+ * problem of integrating with and loading external libraries as part of the
+ * Drupal request-response process in a generic way.
+ *
+ * @section sec_definitions Library definitions
+ * In order to be useful to other modules Libraries API needs a list of known
+ * libraries and metadata about each of the libraries. Because multiple modules
+ * themes may integrate with the same external library a key objective of
+ * Libraries API is to keep this information separate from any one module or
+ * theme.
+ *
+ * Definitions are accessed via a discovery that is responsible for checking
+ * whether a given definition exists and fetching it, if it is. See
+ * LibraryRegistryInterface and StreamDefinitionDiscovery for more information.
+ *
+ * @subsection sub_definitions_machine_name
+ * A central part of a library's metadata is the library's machine name or ID.
+ * For maximum interoperability it must consist of only lowercase ASCII letters,
+ * numbers, and underscores. As the machine name is the single identifier of a
+ * library and is independent of any given module or theme name it must be
+ * unique among all libraries known to Libraries API.
+ *
+ * @subsection sub_definitions_history Historical background
+ * In Drupal 7 library information could already be provided by
+ * module-independent info files, but this was not widely used, because there
+ * was no way to distribute these info files properly. The information was
+ * predominantly provided by a hook that modules could implement, which caused
+ * race conditions between modules providing information for the same library.
+ * Thus, in Drupal 8 there is no longer a hook making it necessary to properly
+ * solve the problem of centrally maintaining and distributing library info
+ * files. This has yet to be done. See https://www.drupal.org/node/773508 for
+ * more information.
+ *
+ * @section sec_types Library types
+ * Libraries are classed objects that implement LibraryInterface. This generic
+ * interface only dictates that a library is aware of its ID. Any further
+ * functionality depends on the type of library, each type of library comes with
+ * a dedicated interface. See LibraryInterface for more information.
+ *
+ * @subsection sub_types_version Version detection
+ * A central aspect of Libraries API is version detection. Modules or themes may
+ * only work with a specific version of an external library, so Libraries API
+ * needs a way to detect the version of a library by inspecting the library
+ * files.
+ *
+ * As the mechanism for doing this is generally not specific to any one
+ * library, it is handled by version detector plugins. A 'line_pattern' plugin
+ * that scans a file line by line whether for whether a pattern containing the
+ * version is matched. It can be used if the version is always specified in a
+ * particular place in a particular file, for example a changelog. See
+ * VersionDetectorInterface and LinePatternDetector for more information.
+ *
+ * @subsection sub_types_dependency Dependency handling
+ * Many libraries depend on other libraries to function. Thus, most library
+ * classes should implement DependentLibraryInterface to allow libraries to
+ * declare their dependencies as part of their metadata. In case of API changes
+ * in the dependencies libraries need to be able to declare dependencies on
+ * specific versions or version ranges of other libraries. This has yet to be
+ * implemented.
+ *
+ * Furthermore, Libraries API must also maintain a list of libraries that are
+ * required by the installed installation profile, modules, and themes
+ * (extensions). With this information installation of extensions with library
+ * dependencies can be prevented until the libraries are properly installed.
+ * This is currently not implemented. In the future this will be used to
+ * automatically retrieve library definitions of required libraries, and
+ * possibly to automatically download the libraries themselves.
+ *
+ * To declare library dependencies extensions can place a 'library_dependencies'
+ * key in their info file with a list of library machine names as the value.
+ * For example:
+ * @code
+ * name: My module
+ * type: module
+ * core: 8.x
+ * library_dependencies:
+ * - flexslider
+ * - jquery_mobile
+ * @endcode
+ *
+ * @subsection sub_types_asset Asset libraries
+ * With Drupal 8 relying on Composer for autoloading and dependency resolution
+ * of PHP libraries, asset libraries are the primary use-case for Libraries API.
+ * Because asset libraries cannot be loaded ad-hoc, but must be attached to a
+ * renderable element, Libraries API registers external asset libraries that are
+ * required by the installed extensions with the core asset library system. See
+ * AssetLibraryInterface for more information.
+ *
+ * @subsection sub_types_php_file
+ * For feature parity with the Drupal 7 version of this module, a PHP file
+ * library type is provided, that can load a list of PHP files on demand.
+ * Generally, it is encouraged to use Composer instead of this library type and
+ * avoid Libraries API altogether for PHP libraries. See PhpFileLibraryInterface
+ * for more information.
+ *
+ * This library type might be removed in a future version of Libraries API.
+ *
+ * @see \Drupal\libraries\ExternalLibrary\Definition\DefinitionDiscoveryInterface
+ * @see \Drupal\libraries\ExternalLibrary\Definition\StreamDefinitionDiscovery
+ * @see \Drupal\libraries\ExternalLibrary\LibraryInterface
+ * @see \Drupal\libraries\ExternalLibrary\Version\VersionDetectorInterface
+ * @see \Drupal\libraries\Plugin\libraries\VersionDetector\LinePatternDetector
+ * @see \Drupal\libraries\ExternalLibrary\Version\VersionedLibraryInterface
+ * @see \Drupal\libraries\ExternalLibrary\Dependency\DependentLibraryInterface
+ * @see \Drupal\libraries\ExternalLibrary\Asset\AssetLibraryInterface
+ * @see \Drupal\libraries\ExternalLibrary\PhpFile\PhpFileLibraryInterface
+ *
+ * @}
+ */
+
+/**
+ * Alter library type information.
+ *
+ * @param array $library_types
+ * An array of library types keyed by ID. Each library type is an array with
+ * the following keys:
+ * - id: The ID of the library type.
+ * - class: The class to use for this library type.
+ * - provider: The provider of this library type.
+ */
+function hook_libraries_library_type_info_alter(array &$library_types) {
+ // Use a different class for the asset library type. Note that this class is
+ // distinct from the class actually for asset libraries themselves.
+ $library_types['asset']['class'] = 'Drupal\mymodule\ExternalLibrary\BetterAssetLibraryType';
+}
+
+/**
+ * Alter library locator information.
+ *
+ * @param array $locators
+ * An array of library locators keyed by ID. Each locator is an array with the
+ * following keys:
+ * - id: The ID of the library locator.
+ * - class: The class to use for this library locator.
+ * - provider: The provider of this library locator.
+ */
+function hook_libraries_locator_info_alter(array &$locators) {
+ // Use a different class for the stream locator.
+ $locators['stream']['class'] = 'Drupal\mymodule\ExternalLibrary\BetterStreamLocator';
+}
+
+/**
+ * Alter library version detector information.
+ *
+ * @param array $version_detectors
+ * An array of library version detectors keyed by ID. Each detector is an
+ * array with the following keys:
+ * - id: The ID of the library version detector.
+ * - class: The class to use for this library version detector.
+ * - provider: The provider of this library version detector.
+ */
+function hook_libraries_version_detector_info_alter(array &$version_detectors) {
+ // Use a different class for the line pattern locator.
+ $version_detectors['line_pattern']['class'] = 'Drupal\mymodule\ExternalLibrary\BetterLinePatternDetector';
+}
+
+/**
+ * Return information about external libraries.
+ *
+ * @return
+ * An associative array whose keys are internal names of libraries and whose
+ * values are describing each library. Each key is the directory name below
+ * the 'libraries' directory, in which the library may be found. Each value is
+ * an associative array containing:
+ * - name: The official, human-readable name of the library.
+ * - vendor url: The URL of the homepage of the library.
+ * - download url: The URL of a web page on which the library can be obtained.
+ * - path: (optional) A relative path from the directory of the library to the
+ * actual library. Only required if the extracted download package contains
+ * the actual library files in a sub-directory.
+ * - library path: (optional) The absolute path to the library directory. This
+ * should not be declared normally, as it is automatically detected, to
+ * allow for multiple possible library locations. A valid use-case is an
+ * external library, in which case the full URL to the library should be
+ * specified here.
+ * - version: (optional) The version of the library. This should not be
+ * declared normally, as it is automatically detected (see 'version
+ * callback' below) to allow for version changes of libraries without code
+ * changes of implementing modules and to support different versions of a
+ * library simultaneously (though only one version can be installed per
+ * site). A valid use-case is an external library whose version cannot be
+ * determined programmatically.
+ * - version callback: (optional) The name of a function that detects and
+ * returns the full version string of the library. The first argument is
+ * always $library, an array containing all library information as described
+ * here. There are two ways to declare the version callback's additional
+ * arguments, either as a single $options parameter or as multiple
+ * parameters, which correspond to the two ways to specify the argument
+ * values (see 'version arguments'). Defaults to libraries_get_version().
+ * - version arguments: A list of arguments to pass to the version callback.
+ * Version arguments can be declared either as an associative array whose
+ * keys are the argument names or as an indexed array without specifying
+ * keys. If declared as an associative array, the arguments get passed to
+ * the version callback as a single $options parameter whose keys are the
+ * argument names (i.e. $options is identical to the specified array). If
+ * declared as an indexed array, the array values get passed to the version
+ * callback as separate arguments in the order they were declared. The
+ * default version callback libraries_get_version() expects a single,
+ * associative array with named keys:
+ * - file: The filename to parse for the version, relative to the library
+ * path. For example: 'docs/changelog.txt'.
+ * - pattern: A string containing a regular expression (PCRE) to match the
+ * library version. For example: '@version\s+([0-9a-zA-Z\.-]+)@'. Note
+ * that the returned version is not the match of the entire pattern (i.e.
+ * '@version 1.2.3' in the above example) but the match of the first
+ * sub-pattern (i.e. '1.2.3' in the above example).
+ * - lines: (optional) The maximum number of lines to search the pattern in.
+ * Defaults to 20.
+ * - cols: (optional) The maximum number of characters per line to take into
+ * account. Defaults to 200. In case of minified or compressed files, this
+ * prevents reading the entire file into memory.
+ * - files: An associative array of library files to load. Supported keys are:
+ * - js: A list of JavaScript files to load, using the same syntax as Drupal
+ * core's hook_library().
+ * - css: A list of CSS files to load, using the same syntax as Drupal
+ * core's hook_library().
+ * - php: A list of PHP files to load.
+ * - dependencies: An array of libraries this library depends on. Similar to
+ * declaring module dependencies, the dependency declaration may contain
+ * information on the supported version. Examples of supported declarations:
+ * @code
+ * $libraries['dependencies'] = array(
+ * // Load the 'example' library, regardless of the version available:
+ * 'example',
+ * // Only load the 'example' library, if version 1.2 is available:
+ * 'example (1.2)',
+ * // Only load a version later than 1.3-beta2 of the 'example' library:
+ * 'example (>1.3-beta2)'
+ * // Only load a version equal to or later than 1.3-beta3:
+ * 'example (>=1.3-beta3)',
+ * // Only load a version earlier than 1.5:
+ * 'example (<1.5)',
+ * // Only load a version equal to or earlier than 1.4:
+ * 'example (<=1.4)',
+ * // Combinations of the above are allowed as well:
+ * 'example (>=1.3-beta2, <1.5)',
+ * );
+ * @endcode
+ * - variants: (optional) An associative array of available library variants.
+ * For example, the top-level 'files' property may refer to a default
+ * variant that is compressed. If the library also ships with a minified and
+ * uncompressed/source variant, those can be defined here. Each key should
+ * describe the variant type, e.g. 'minified' or 'source'. Each value is an
+ * associative array of top-level properties that are entirely overridden by
+ * the variant, most often just 'files'. Additionally, each variant can
+ * contain following properties:
+ * - variant callback: (optional) The name of a function that detects the
+ * variant and returns TRUE or FALSE, depending on whether the variant is
+ * available or not. The first argument is always $library, an array
+ * containing all library information as described here. The second
+ * argument is always a string containing the variant name. There are two
+ * ways to declare the variant callback's additional arguments, either as a
+ * single $options parameter or as multiple parameters, which correspond
+ * to the two ways to specify the argument values (see 'variant
+ * arguments'). If omitted, the variant is expected to always be
+ * available.
+ * - variant arguments: A list of arguments to pass to the variant callback.
+ * Variant arguments can be declared either as an associative array whose
+ * keys are the argument names or as an indexed array without specifying
+ * keys. If declared as an associative array, the arguments get passed to
+ * the variant callback as a single $options parameter whose keys are the
+ * argument names (i.e. $options is identical to the specified array). If
+ * declared as an indexed array, the array values get passed to the
+ * variant callback as separate arguments in the order they were declared.
+ * Variants can be version-specific (see 'versions').
+ * - versions: (optional) An associative array of supported library versions.
+ * Naturally, libraries evolve over time and so do their APIs. In case a
+ * library changes between versions, different 'files' may need to be
+ * loaded, different 'variants' may become available, or Drupal modules need
+ * to load different integration files adapted to the new version. Each key
+ * is a version *string* (PHP does not support floats as keys). Each value
+ * is an associative array of top-level properties that are entirely
+ * overridden by the version.
+ * - integration files: (optional) An associative array whose keys are module
+ * names and whose values are sets of files to load for the module, using
+ * the same notion as the top-level 'files' property. Each specified file
+ * should contain the path to the file relative to the module it belongs to.
+ * - callbacks: An associative array whose keys are callback groups and whose
+ * values are arrays of callbacks to apply to the library in that group.
+ * Each callback receives the following arguments:
+ * - $library: An array of library information belonging to the top-level
+ * library, a specific version, a specific variant or a specific variant
+ * of a specific version. Because library information such as the 'files'
+ * property (see above) can be declared in all these different locations
+ * of the library array, but a callback may have to act on all these
+ * different parts of the library, it is called recursively for each
+ * library with a certain part of the libraries array passed as $library
+ * each time.
+ * - $version: If the $library array belongs to a certain version (see
+ * above), a string containing the version. This argument may be empty, so
+ * NULL should be specified as the default value.
+ * - $variant: If the $library array belongs to a certain variant (see
+ * above), a string containing the variant name. This argument may be
+ * empty, so NULL should be specified as the default value.
+ * Valid callback groups are:
+ * - info: Callbacks registered in this group are applied after the library
+ * information has been retrieved via hook_libraries_info() or info files.
+ * - pre-detect: Callbacks registered in this group are applied after the
+ * library path has been determined and before the version callback is
+ * invoked. At this point the following additional information is available:
+ * - $library['library path']: The path on the file system to the library.
+ * - post-detect: Callbacks registered in this group are applied after the
+ * library has been successfully detected. At this point the library
+ * contains the version-specific information, if specified, and following
+ * additional information is available:
+ * - $library['installed']: A boolean indicating whether the library is
+ * installed or not.
+ * - $library['version']: If it could be detected, a string containing the
+ * version of the library.
+ * - $library['variants'][$variant]['installed']: For each specified
+ * variant, a boolean indicating whether the variant is installed or
+ * not.
+ * Note that in this group the 'versions' property is no longer available.
+ * - pre-load: Callbacks registered in this group are applied directly
+ * before this library is loaded. At this point the library contains
+ * variant-specific information, if specified. Note that in this group the
+ * 'variants' property is no longer available.
+ * - post-load: Callbacks registered in this group are applied directly
+ * after this library is loaded. At this point, the library contains a
+ * 'loaded' key, which contains the number of files that were loaded.
+ * Additional top-level properties can be registered as needed.
+ *
+ * @see hook_library()
+ *
+ * @deprecated Will be removed before a stable Drupal 8 release.
+ */
+function hook_libraries_info() {
+ // The following is a full explanation of all properties. See below for more
+ // concrete example implementations.
+
+ // This array key lets Libraries API search for 'sites/all/libraries/example'
+ // directory, which should contain the entire, original extracted library.
+ $libraries['example'] = array(
+ // Only used in administrative UI of Libraries API.
+ 'name' => 'Example library',
+ 'vendor url' => 'http://example.com',
+ 'download url' => 'http://example.com/download',
+ // Optional: If, after extraction, the actual library files are contained in
+ // 'sites/all/libraries/example/lib', specify the relative path here.
+ 'path' => 'lib',
+ // Optional: Define a custom version detection callback, if required.
+ 'version callback' => 'mymodule_get_version',
+ // Specify arguments for the version callback. By default,
+ // libraries_get_version() takes a named argument array:
+ 'version arguments' => array(
+ 'file' => 'docs/CHANGELOG.txt',
+ 'pattern' => '@version\s+([0-9a-zA-Z\.-]+)@',
+ 'lines' => 5,
+ 'cols' => 20,
+ ),
+ // Default list of files of the library to load. Important: Only specify
+ // third-party files belonging to the library here, not integration files of
+ // your module.
+ 'files' => array(
+ // 'js' and 'css' follow the syntax of hook_library(), but file paths are
+ // relative to the library path.
+ 'js' => array(
+ 'exlib.js',
+ 'gadgets/foo.js',
+ ),
+ 'css' => array(
+ 'lib_style.css',
+ 'skin/example.css',
+ ),
+ // For PHP libraries, specify include files here, still relative to the
+ // library path.
+ 'php' => array(
+ 'exlib.php',
+ 'exlib.inc',
+ ),
+ ),
+ // Optional: Specify alternative variants of the library, if available.
+ 'variants' => array(
+ // All properties defined for 'minified' override top-level properties.
+ 'minified' => array(
+ 'files' => array(
+ 'js' => array(
+ 'exlib.min.js',
+ 'gadgets/foo.min.js',
+ ),
+ 'css' => array(
+ 'lib_style.css',
+ 'skin/example.css',
+ ),
+ ),
+ 'variant callback' => 'mymodule_check_variant',
+ 'variant arguments' => array(
+ 'variant' => 'minified',
+ ),
+ ),
+ ),
+ // Optional, but usually required: Override top-level properties for later
+ // versions of the library. The properties of the minimum version that is
+ // matched override the top-level properties. Note:
+ // - When registering 'versions', it usually does not make sense to register
+ // 'files', 'variants', and 'integration files' on the top-level, as most
+ // of those likely need to be different per version and there are no
+ // defaults.
+ // - The array keys have to be strings, as PHP does not support floats for
+ // array keys.
+ 'versions' => array(
+ '2' => array(
+ 'files' => array(
+ 'js' => array('exlib.js'),
+ 'css' => array('exlib_style.css'),
+ ),
+ ),
+ '3.0' => array(
+ 'files' => array(
+ 'js' => array('exlib.js'),
+ 'css' => array('lib_style.css'),
+ ),
+ ),
+ '3.2' => array(
+ 'files' => array(
+ 'js' => array(
+ 'exlib.js',
+ 'gadgets/foo.js',
+ ),
+ 'css' => array(
+ 'lib_style.css',
+ 'skin/example.css',
+ ),
+ ),
+ ),
+ ),
+ // Optional: Register files to auto-load for your module. All files must be
+ // keyed by module, and follow the syntax of the 'files' property.
+ 'integration files' => array(
+ 'mymodule' => array(
+ 'js' => array('ex_lib.inc'),
+ ),
+ ),
+ // Optionally register callbacks to apply to the library during different
+ // stages of its lifetime ('callback groups').
+ 'callbacks' => array(
+ // Used to alter the info associated with the library.
+ 'info' => array(
+ 'mymodule_example_libraries_info_callback',
+ ),
+ // Called before detecting the given library.
+ 'pre-detect' => array(
+ 'mymodule_example_libraries_predetect_callback',
+ ),
+ // Called after detecting the library.
+ 'post-detect' => array(
+ 'mymodule_example_libraries_postdetect_callback',
+ ),
+ // Called before the library is loaded.
+ 'pre-load' => array(
+ 'mymodule_example_libraries_preload_callback',
+ ),
+ // Called after the library is loaded.
+ 'post-load' => array(
+ 'mymodule_example_libraries_postload_callback',
+ ),
+ ),
+ );
+
+ // A very simple library. No changing APIs (hence, no versions), no variants.
+ // Expected to be extracted into 'sites/all/libraries/simple'.
+ $libraries['simple'] = array(
+ 'name' => 'Simple library',
+ 'vendor url' => 'http://example.com/simple',
+ 'download url' => 'http://example.com/simple',
+ 'version arguments' => array(
+ 'file' => 'readme.txt',
+ // Best practice: Document the actual version strings for later reference.
+ // 1.x: Version 1.0
+ 'pattern' => '/Version (\d+)/',
+ 'lines' => 5,
+ ),
+ 'files' => array(
+ 'js' => array('simple.js'),
+ ),
+ );
+
+ // A library that (naturally) evolves over time with API changes.
+ $libraries['tinymce'] = array(
+ 'name' => 'TinyMCE',
+ 'vendor url' => 'http://tinymce.moxiecode.com',
+ 'download url' => 'http://tinymce.moxiecode.com/download.php',
+ 'path' => 'jscripts/tiny_mce',
+ // The regular expression catches two parts (the major and the minor
+ // version), which libraries_get_version() doesn't allow.
+ 'version callback' => 'tinymce_get_version',
+ 'version arguments' => array(
+ // It can be easier to parse the first characters of a minified file
+ // instead of doing a multi-line pattern matching in a source file. See
+ // 'lines' and 'cols' below.
+ 'file' => 'jscripts/tiny_mce/tiny_mce.js',
+ // Best practice: Document the actual version strings for later reference.
+ // 2.x: this.majorVersion="2";this.minorVersion="1.3"
+ // 3.x: majorVersion:'3',minorVersion:'2.0.1'
+ 'pattern' => '@majorVersion[=:]["\'](\d).+?minorVersion[=:]["\']([\d\.]+)@',
+ 'lines' => 1,
+ 'cols' => 100,
+ ),
+ 'versions' => array(
+ '2.1' => array(
+ 'files' => array(
+ 'js' => array('tiny_mce.js'),
+ ),
+ 'variants' => array(
+ 'source' => array(
+ 'files' => array(
+ 'js' => array('tiny_mce_src.js'),
+ ),
+ ),
+ ),
+ 'integration files' => array(
+ 'wysiwyg' => array(
+ 'js' => array('editors/js/tinymce-2.js'),
+ 'css' => array('editors/js/tinymce-2.css'),
+ ),
+ ),
+ ),
+ // Definition used if 3.1 or above is detected.
+ '3.1' => array(
+ // Does not support JS aggregation.
+ 'files' => array(
+ 'js' => array(
+ 'tiny_mce.js' => array('preprocess' => FALSE),
+ ),
+ ),
+ 'variants' => array(
+ // New variant leveraging jQuery. Not stable yet; therefore not the
+ // default variant.
+ 'jquery' => array(
+ 'files' => array(
+ 'js' => array(
+ 'tiny_mce_jquery.js' => array('preprocess' => FALSE),
+ ),
+ ),
+ ),
+ 'source' => array(
+ 'files' => array(
+ 'js' => array(
+ 'tiny_mce_src.js' => array('preprocess' => FALSE),
+ ),
+ ),
+ ),
+ ),
+ 'integration files' => array(
+ 'wysiwyg' => array(
+ 'js' => array('editors/js/tinymce-3.js'),
+ 'css' => array('editors/js/tinymce-3.css'),
+ ),
+ ),
+ ),
+ ),
+ );
+ return $libraries;
+}
+
+/**
+ * Alter the library information before detection and caching takes place.
+ *
+ * The library definitions are passed by reference. A common use-case is adding
+ * a module's integration files to the library array, so that the files are
+ * loaded whenever the library is. As noted above, it is important to declare
+ * integration files inside of an array, whose key is the module name.
+ *
+ * @see hook_libraries_info()
+ *
+ * @deprecated Will be removed before a stable Drupal 8 release.
+ */
+function hook_libraries_info_alter(&$libraries) {
+ $files = array(
+ 'php' => array('example_module.php_spellchecker.inc'),
+ );
+ $libraries['php_spellchecker']['integration files']['example_module'] = $files;
+}
+
+/**
+ * Specify paths to look for library info files.
+ *
+ * Libraries API looks in the following directories for library info files by
+ * default:
+ * - libraries
+ * - profiles/$profile/libraries
+ * - sites/all/libraries
+ * - sites/$site/libraries
+ * This hook allows you to specify additional locations to look for library info
+ * files. This should only be used for modules that declare many libraries.
+ * Modules that only implement a few libraries should implement
+ * hook_libraries_info().
+ *
+ * @return
+ * An array of paths.
+ *
+ * @deprecated Will be removed before a stable Drupal 8 release.
+ */
+function hook_libraries_info_file_paths() {
+ // Taken from the Libraries test module, which needs to specify the path to
+ // the test library.
+ return array(drupal_get_path('module', 'libraries_test') . '/example');
+}