rules.api.php

<?php

/**
 * @file
 * This file contains no working PHP code; it exists to provide additional
 * documentation for doxygen as well as to document hooks in the standard
 * Drupal manner.
 */


/**
 * @defgroup rules Rules module integrations.
 *
 * Module integrations with the rules module.
 *
 * The Rules developer documentation describes how modules can integrate with
 * rules: http://drupal.org/node/298486.
 */

/**
 * @defgroup rules_hooks Rules' hooks
 * @{
 * Hooks that can be implemented by other modules in order to extend rules.
 */

/**
 * Define rules compatible actions.
 *
 * This hook is required in order to add a new rules action. It should be
 * placed into the file MODULENAME.rules.inc, which gets automatically included
 * when the hook is invoked.
 *
 * However, as an alternative to implementing this hook, class based plugin
 * handlers may be provided by implementing RulesActionHandlerInterface. See
 * the interface for details.
 *
 * @return
 *   An array of information about the module's provided rules actions.
 *   The array contains a sub-array for each action, with the action name as
 *   the key. Actions names may only contain lowercase alpha-numeric characters
 *   and underscores and should be prefixed with the providing module name.
 *   Possible attributes for each sub-array are:
 *   - label: The label of the action. Start capitalized. Required.
 *   - group: A group for this element, used for grouping the actions in the
 *     interface. Should start with a capital letter and be translated.
 *     Required.
 *   - parameter: (optional) An array describing all parameter of the action
 *     with the parameter's name as key. Each parameter has to be
 *     described by a sub-array with possible attributes as described
 *     afterwards, whereas the name of a parameter needs to be a lowercase,
 *     valid PHP variable name.
 *   - provides: (optional) An array describing the variables the action
 *     provides to the evaluation state with the variable name as key. Each
 *     variable has to be described by a sub-array with possible attributes as
 *     described afterwards, whereas the name of a parameter needs to be a
 *     lowercase, valid PHP variable name.
 *   - 'named parameter': (optional) If set to TRUE, the arguments will be
 *     passed as a single array with the parameter names as keys. This emulates
 *     named parameters in PHP and is in particular useful if the number of
 *     parameters can vary. Defaults to FALSE.
 *   - base: (optional) The base for action implementation callbacks to use
 *     instead of the action's name. Defaults to the action name.
 *   - callbacks: (optional) An array which allows to set specific function
 *     callbacks for the action. The default for each callback is the actions
 *     base appended by '_' and the callback name.
 *   - 'access callback': (optional) A callback which has to return whether the
 *     currently logged in user is allowed to configure this action. See
 *     rules_node_integration_access() for an example callback.
 *  Each 'parameter' array may contain the following properties:
 *   - label: The label of the parameter. Start capitalized. Required.
 *   - type: The rules data type of the parameter, which is to be passed to the
 *     action. All types declared in hook_rules_data_info() may be specified, as
 *     well as an array of possible types. Also lists and lists of a given type
 *     can be specified by using the notating list<integer> as introduced by
 *     the entity metadata module, see hook_entity_property_info(). The special
 *     keyword '*' can be used when all types should be allowed. Required.
 *   - bundles: (optional) An array of bundle names. When the specified type is
 *     set to a single entity type, this may be used to restrict the allowed
 *     bundles.
 *   - description: (optional) If necessary, a further description of the
 *     parameter.
 *   - options list: (optional) A callback that returns an array of possible
 *     values for this parameter. The callback has to return an array as used
 *     by hook_options_list(). For an example implementation see
 *     rules_data_action_type_options().
 *   - save: (optional) If this is set to TRUE, the parameter will be saved by
 *     rules when the rules evaluation ends. This is only supported for savable
 *     data types. If the action returns FALSE, saving is skipped.
 *   - optional: (optional) May be set to TRUE, when the parameter isn't
 *     required.
 *   - 'default value': (optional) The value to pass to the action, in case the
 *     parameter is optional and there is no specified value.
 *   - 'allow null': (optional) Usually Rules will not pass any NULL values as
 *     argument, but abort the evaluation if a NULL value is present. If set to
 *     TRUE, Rules will not abort and pass the NULL value through. Defaults to
 *     FALSE.
 *   - restriction: (optional) Restrict how the argument for this parameter may
 *     be provided. Supported values are 'selector' and 'input'.
 *   - default mode: (optional) Customize the default mode for providing the
 *     argument value for a parameter. Supported values are 'selector' and
 *     'input'. The default depends on the required data type.
 *   - sanitize: (optional) Allows parameters of type 'text' to demand an
 *     already sanitized argument. If enabled, any user specified value won't be
 *     sanitized itself, but replacements applied by input evaluators are as
 *     well as values retrieved from selected data sources.
 *   - translatable: (optional) If set to TRUE, the provided argument value
 *     of the parameter is translatable via i18n String translation. This is
 *     applicable for textual parameters only, i.e. parameters of type 'text',
 *     'token', 'list<text>' and 'list<token>'. Defaults to FALSE.
 *   - ui class: (optional) Allows overriding the UI class, which is used to
 *     generate the configuration UI of a parameter. Defaults to the UI class of
 *     the specified data type.
 *   - cleaning callback: (optional) A callback that input evaluators may use
 *     to clean inserted replacements; e.g. this is used by the token evaluator.
 *   - wrapped: (optional) Set this to TRUE in case the data should be passed
 *     wrapped. This only applies to wrapped data types, e.g. entities.
 *  Each 'provides' array may contain the following properties:
 *   - label: The label of the variable. Start capitalized. Required.
 *   - type: The rules data type of the variable. All types declared in
 *     hook_rules_data_info() may be specified. Types may be parametrized e.g.
 *     the types node<page> or list<integer> are valid.
 *   - save: (optional) If this is set to TRUE, the provided variable is saved
 *     by rules when the rules evaluation ends. Only possible for savable data
 *     types. Defaults to FALSE.
 *
 *  The module has to provide an implementation for each action, being a
 *  function named as specified in the 'base' key or for the execution callback.
 *  All other possible callbacks are optional.
 *  Supported action callbacks by rules are defined and documented in the
 *  RulesPluginImplInterface. However any module may extend the action plugin
 *  based upon a defined interface using hook_rules_plugin_info(). All methods
 *  defined in those interfaces can be overridden by the action implementation.
 *  The callback implementations for those interfaces may reside in any file
 *  specified in hook_rules_file_info().
 *
 *  @see hook_rules_file_info()
 *  @see rules_action_execution_callback()
 *  @see hook_rules_plugin_info()
 *  @see RulesPluginImplInterface
 */
function hook_rules_action_info() {
  return array(
    'mail_user' => array(
      'label' => t('Send a mail to a user'),
      'parameter' => array(
        'user' => array('type' => 'user', 'label' => t('Recipient')),
      ),
      'group' => t('System'),
      'base' => 'rules_action_mail_user',
      'callbacks' => array(
        'validate' => 'rules_action_custom_validation',
        'help' => 'rules_mail_help',
      ),
    ),
  );
}

/**
 * Define categories for Rules items, e.g. actions, conditions or events.
 *
 * Categories are similar to the previously used 'group' key in e.g.
 * hook_rules_action_info(), but have a machine name and some more optional
 * keys like a weight, or an icon.
 *
 * For best compatibility, modules may keep using the 'group' key for referring
 * to categories. However, if a 'group' key and a 'category' is given the group
 * will be treated as grouping in the given category (e.g. group "paypal" in
 * category "commerce payment").
 *
 * @return
 *   An array of information about the module's provided categories.
 *   The array contains a sub-array for each category, with the category name as
 *   the key. Names may only contain lowercase alpha-numeric characters
 *   and underscores and should be prefixed with the providing module name.
 *   Possible attributes for each sub-array are:
 *   - label: The label of the category. Start capitalized. Required.
 *   - weight: (optional) A weight for sorting the category. Defaults to 0.
 *   - equals group: (optional) For BC, categories may be defined that equal
 *     a previously used 'group'.
 *   - icon: (optional) The file path of an icon to use, relative to the module
 *     or specified icon path. The icon should be a transparent SVG containing
 *     no colors (only #fff). See https://drupal.org/node/2090265 for
 *     instructions on how to create a suiting icon.
 *     Note that the icon is currently not used by Rules, however other UIs
 *     building upon Rules (like fluxkraft) do, and future releases of Rules
 *     might do as well. Consequently, the definition of an icon is optional.
 *     However, if both an icon font and icon is given, the icon is preferred.
 *   - icon path: (optional) The base path for the icon. Defaults to the
 *     providing module's directory.
 *   - icon font class: (optional) An icon font class referring to a suiting
 *     icon. Icon font class names should map to the ones as defined by Font
 *     Awesome, while themes might want to choose to provide another icon font.
 *     See http://fortawesome.github.io/Font-Awesome/cheatsheet/.
 *   - icon background color: (optional) The color used as icon background.
 *     Should have a high contrast to white. Defaults to #ddd.
 */
function hook_rules_category_info() {
  return array(
    'rules_data' => array(
      'label' => t('Data'),
      'equals group' => t('Data'),
      'weight' => -50,
    ),
    'fluxtwitter' => array(
      'label' => t('Twitter'),
      'icon font class' => 'icon-twitter',
      'icon font background color' => '#30a9fd',
    ),
  );
}

/**
 * Specify files containing rules integration code.
 *
 * All files specified in that hook will be included when rules looks for
 * existing callbacks for any plugin. Rules remembers which callback is found in
 * which file and automatically includes the right file before it is executing
 * a plugin method callback. The file yourmodule.rules.inc is added by default
 * and need not be specified here.
 * This allows you to add new include files only containing functions serving as
 * plugin method callbacks in any file without having to care about file
 * inclusion.
 *
 * @return
 *   An array of file names without the file ending which defaults to '.inc'.
 */
function hook_rules_file_info() {
  return array('yourmodule.rules-eval');
}

/**
 * Specifies directories for class-based plugin handler discovery.
 *
 * Implementing this hook is not a requirement, it is just one option to load
 * the files containing the classes during discovery - see
 * rules_discover_plugins().
 *
 * @return string|array
 *   A directory relative to the module directory, which holds the files
 *   containing rules plugin handlers, or multiple directories keyed by the
 *   module the directory is contained in.
 *   All files in those directories having a 'php' or 'inc' file extension will
 *   be loaded during discovery. Optionally, wildcards ('*') may be used to
 *   match multiple directories.
 *
 * @see rules_discover_plugins()
 */
function hook_rules_directory() {
  return 'lib/Drupal/fluxtwitter/Rules/*';
}

/**
 * The execution callback for an action.
 *
 * It should be placed in any file included by your module or in a file
 * specified using hook_rules_file_info().
 *
 * @param
 *   The callback gets arguments passed as described as parameter in
 *   hook_rules_action_info() as well as an array containing the action's
 *   configuration settings.
 * @return
 *   The action may return an array containing parameter or provided variables
 *   with their names as key. This is used update the value of a parameter or to
 *   provide the value for a provided variable.
 *   Apart from that any parameters which have the key 'save' set to TRUE will
 *   be remembered to be saved by rules unless the action returns FALSE.
 *   Conditions have to return a boolean value in any case.
 *
 * @see hook_rules_action_info()
 * @see hook_rules_file_info()
 */
function rules_action_execution_callback($node, $title, $settings) {
  $node->title = $title;
  return array('node' => $node);
}

/**
 * Define rules conditions.
 *
 * This hook is required in order to add a new rules condition. It should be
 * placed into the file MODULENAME.rules.inc, which gets automatically included
 * when the hook is invoked.
 *
 * However, as an alternative to implementing this hook, class based plugin
 * handlers may be provided by implementing RulesConditionHandlerInterface. See
 * the interface for details.
 *
 * Adding conditions works exactly the same way as adding actions, with the
 * exception that conditions can't provide variables and cannot save parameters.
 * Thus the 'provides' attribute is not supported. Furthermore the condition
 * implementation callback has to return a boolean value.
 *
 * @see hook_rules_action_info()
 */
function hook_rules_condition_info() {
  return array(
    'rules_condition_text_compare' => array(
      'label' => t('Textual comparison'),
      'parameter' => array(
        'text1' => array('label' => t('Text 1'), 'type' => 'text'),
        'text2' => array('label' => t('Text 2'), 'type' => 'text'),
      ),
      'group' => t('Rules'),
    ),
  );
}

/**
 * Define rules events.
 *
 * This hook is required in order to add a new rules event. It should be
 * placed into the file MODULENAME.rules.inc, which gets automatically included
 * when the hook is invoked.
 * The module has to invoke the event when it occurs using rules_invoke_event().
 * This function call has to happen outside of MODULENAME.rules.inc,
 * usually it's invoked directly from the providing module but wrapped by a
 * module_exists('rules') check.
 *
 * However, as an alternative to implementing this hook, class based event
 * handlers may be provided by implementing RulesEventHandlerInterface. See
 * the interface for details.
 *
 * @return
 *   An array of information about the module's provided rules events. The array
 *   contains a sub-array for each event, with the event name as the key. The
 *   name may only contain lower case alpha-numeric characters and underscores
 *   and should be prefixed with the providing module name. Possible attributes
 *   for each sub-array are:
 *   - label: The label of the event. Start capitalized. Required.
 *   - group: A group for this element, used for grouping the events in the
 *     interface. Should start with a capital letter and be translated.
 *     Required.
 *   - class: (optional) An event handler class implementing the
 *     RulesEventHandlerInterface. If none is specified the
 *     RulesEventDefaultHandler class will be used. While the default event
 *     handler has no settings, custom event handlers may be implemented to
 *     to make an event configurable. See RulesEventHandlerInterface.
 *   - access callback: (optional) An callback, which has to return whether the
 *     currently logged in user is allowed to configure rules for this event.
 *     Access should be only granted, if the user at least may access all the
 *     variables provided by the event.
 *   - help: (optional) A help text for rules reaction on this event.
 *   - variables: (optional) An array describing all variables that are
 *     available for elements reacting on this event. Each variable has to be
 *     described by a sub-array with the possible attributes:
 *     - label: The label of the variable. Start capitalized. Required.
 *     - type: The rules data type of the variable. All types declared in
 *       hook_rules_data_info() or supported by hook_entity_property_info() may
 *       be specified.
 *     - bundle: (optional) If the type is an entity type, the bundle of the
 *       entity.
 *     - description: (optional) A description for the variable.
 *     - 'options list': (optional) A callback that returns an array of possible
 *       values for this variable as specified for entity properties at
 *       hook_entity_property_info().
 *     - 'skip save': (optional) If the variable is saved after the event has
 *       occurred anyway, set this to TRUE. So rules won't save the variable a
 *       second time. Defaults to FALSE.
 *     - handler: (optional) A handler to load the actual variable value. This
 *       is useful for lazy loading variables. The handler gets all so far
 *       available variables passed in the order as defined. Also see
 *       http://drupal.org/node/884554.
 *       Note that for lazy-loading entities just the entity id may be passed
 *       as variable value, so a handler is not necessary in that case.
 *
 *  @see rules_invoke_event()
 */
function hook_rules_event_info() {
  $items = array(
    'node_insert' => array(
      'label' => t('After saving new content'),
      'group' => t('Node'),
      'variables' => rules_events_node_variables(t('created content')),
    ),
    'node_update' => array(
      'label' => t('After updating existing content'),
      'group' => t('Node'),
      'variables' => rules_events_node_variables(t('updated content'), TRUE),
    ),
    'node_presave' => array(
      'label' => t('Content is going to be saved'),
      'group' => t('Node'),
      'variables' => rules_events_node_variables(t('saved content'), TRUE),
    ),
    'node_view' => array(
      'label' => t('Content is going to be viewed'),
      'group' => t('Node'),
      'variables' => rules_events_node_variables(t('viewed content')) + array(
        'view_mode' => array('type' => 'text', 'label' => t('view mode')),
      ),
    ),
    'node_delete' => array(
      'label' => t('After deleting content'),
      'group' => t('Node'),
      'variables' => rules_events_node_variables(t('deleted content')),
    ),
  );
  // Specify that on presave the node is saved anyway.
  $items['node_presave']['variables']['node']['skip save'] = TRUE;
  return $items;
}

/**
 * Define rules data types.
 *
 * This hook is required in order to add a new rules data type. It should be
 * placed into the file MODULENAME.rules.inc, which gets automatically included
 * when the hook is invoked.
 * Rules builds upon the entity metadata module, thus to improve the support of
 * your data in rules, make it an entity if possible and provide metadata about
 * its properties and CRUD functions by integrating with the entity metadata
 * module.
 * For a list of data types defined by rules see rules_rules_core_data_info().
 *
 *
 * @return
 *   An array of information about the module's provided data types. The array
 *   contains a sub-array for each data type, with the data type name as the
 *   key. The name may only contain lower case alpha-numeric characters and
 *   underscores and should be prefixed with the providing module name. Possible
 *   attributes for each sub-array are:
 *   - label: The label of the data type. Start uncapitalized. Required.
 *   - parent: (optional) A parent type may be set to specify a sub-type
 *     relationship, which will be only used for checking compatible types. E.g.
 *     the 'entity' data type is parent of the 'node' data type, thus a node may
 *     be also used for any action needing an 'entity' parameter. Can be set to
 *     any known rules data type.
 *   - ui class: (optional) Specify a class that is used to generate the
 *     configuration UI to configure parameters of this type. The given class
 *     must extend RulesDataUI and may implement the
 *     RulesDataDirectInputFormInterface in order to allow the direct data input
 *     configuration mode. For supporting selecting values from options lists,
 *     the UI class may implement RulesDataInputOptionsListInterface also.
 *     Defaults to RulesDataUI.
 *   - wrap: (optional) If set to TRUE, the data is wrapped internally using
 *     wrappers provided by the entity API module. This is required for entities
 *     and data structures to support selecting a property via the data selector
 *     and for intelligent saving.
 *   - is wrapped: (optional) In case the data wrapper is already wrapped when
 *     passed to Rules and Rules should not unwrap it when passing the data as
 *     argument, e.g. to an action, set this to TRUE. The default FALSE is fine
 *     in most cases.
 *   - wrapper class: (optional) Allows the specification of a custom wrapper
 *     class, which has to inherit from 'EntityMetadataWrapper'. If given Rules
 *     makes use of the class for wrapping the data of the given type. However
 *     note that if data is already wrapped when it is passed to Rules, the
 *     existing wrappers will be kept.
 *     For modules implementing identifiable data types being non-entities the
 *     class RulesIdentifiableDataWrapper is provided, which can be used as base
 *     for a custom wrapper class. See RulesIdentifiableDataWrapper for details.
 *   - property info: (optional) May be used for non-entity data structures to
 *     provide info about the data properties, such that data selectors via an
 *     entity metadata wrapper are supported. Specify an array as expected by
 *     the $info parameter of entity_metadata_wrapper().
 *   - creation callback: (optional) If 'property info' is given, an optional
 *     callback that makes use of the property info to create a new instance of
 *     this data type. Entities should use hook_entity_info() to specify the
 *     'creation callback' instead, as utilized by the entity API module. See
 *     rules_action_data_create_array() for an example callback.
 *   - property defaults: (optional) May be used for non-entity data structures
 *     to to provide property info defaults for the data properties. Specify an
 *     array as expected by entity_metadata_wrapper().
 *   - group: (optional) A group for this element, used for grouping the data
 *     types in the interface. Should start with a capital letter and be
 *     translated.
 *   - token type: (optional) The type name as used by the token module.
 *     Defaults to the type name as used by rules. Use FALSE to let token ignore
 *     this type.
 *   - cleaning callback: (optional) A callback that input evaluators may use
 *     to clean inserted replacements; e.g. this is used by the token evaluator.
 *
 *  @see entity_metadata_wrapper()
 *  @see hook_rules_data_info_alter()
 *  @see rules_rules_core_data_info()
 */
function hook_rules_data_info() {
  return array(
    'node' => array(
      'label' => t('content'),
      'parent' => 'entity',
      'group' => t('Node'),
    ),
    // Formatted text as used by in hook_entity_property_info() for text fields.
    'text_formatted' => array(
      'label' => t('formatted text'),
      'ui class' => 'RulesDataUITextFormatted',
      'wrap' => TRUE,
      'property info' => entity_property_text_formatted_info(),
    ),
  );
}

/**
 * Defines rules plugins.
 *
 * A rules configuration may consist of elements being instances of any rules
 * plugin. This hook can be used to define new or to extend rules plugins.
 *
 * @return
 *   An array of information about the module's provided rules plugins. The
 *   array contains a sub-array for each plugin, with the plugin name as the
 *   key. The name may only contain lower case alpha-numeric characters,
 *   underscores and spaces and should be prefixed with the providing module
 *   name. Possible attributes for
 *   each sub-array are:
 *   - label: A label for the plugin. Start capitalized. Required only for
 *     components (see below).
 *   - class: The implementation class. Has to extend the RulesPlugin class.
 *   - embeddable: A container class in which elements of those plugin may be
 *     embedded via the UI or FALSE to disallow embedding it via the UI. This
 *     has no implications on the API level though. Common classes that are
 *     used here are RulesConditionContainer and RulesActionContainer.
 *   - component: If set to TRUE, the rules admin UI will list elements of those
 *     plugin in the components UI and allows the creation of new components
 *     based upon this plugin. Optional.
 *   - extenders: This allows one to specify faces extenders, which may be used
 *     to dynamically implement interfaces. Optional. All extenders specified
 *     here are setup automatically by rules once the object is created. To
 *     specify set this to an array, where the keys are the implemented
 *     interfaces pointing to another array with the keys:
 *     - class: The class of the extender, implementing the FacesExtender
 *       and the specified interface. Either 'class' or 'methods' has to exist.
 *     - methods: An array of callbacks that implement the methods of the
 *       interface where the method names are the keys and the callback names
 *       the values. There has to be a callback for each defined method.
 *     - file: An optional array describing the file to include when a method
 *       of the interface is invoked. The array entries known are 'type',
 *       'module', and 'name' matching the parameters of module_load_include().
 *       Only 'module' is required as 'type' defaults to 'inc' and 'name' to
 *       NULL.
 *   - overrides: An optional array, which may be used to specify callbacks to
 *     override specific methods. For that the following keys are supported:
 *     - methods: As in the extenders array, but you may specify as many methods
 *       here as you like.
 *     - file: Optionally an array specifying a file to include for a method.
 *       For each method appearing in methods a file may be specified by using
 *       the method name as key and another array as value, which describes the
 *       file to include - looking like the file array supported by 'extenders'.
 *   - import keys: (optional) Embeddable plugins may specify an array of import
 *     keys, which the plugin make use for exporting. Defaults to the upper
 *     case plugin name, thus the key 'OR' in an export triggers the creation
 *     of the 'or' plugin. Note that only uppercase values are allowed, as
 *     lower case values are treated as action or condition exports.
 *
 *  @see class RulesPlugin
 *  @see hook_rules_plugin_info_alter()
 */
function hook_rules_plugin_info() {
  return array(
    'or' => array(
      'label' => t('Condition set (OR)'),
      'class' => 'RulesOr',
      'embeddable' => 'RulesConditionContainer',
      'component' => TRUE,
      'extenders' => array(
        'RulesPluginUIInterface' => array(
          'class' => 'RulesConditionContainerUI',
        ),
      ),
    ),
    'rule' => array(
      'class' => 'Rule',
      'embeddable' => 'RulesRuleSet',
      'extenders' => array(
        'RulesPluginUIInterface' => array(
          'class' => 'RulesRuleUI',
        ),
      ),
      'import keys' => array('DO', 'IF'),
    ),
  );
}

/**
 * Declare provided rules input evaluators.
 *
 * The hook implementation should be placed into the file MODULENAME.rules.inc,
 * which gets automatically included when the hook is invoked.
 * For implementing an input evaluator a class has to be provided which
 * extends the abstract RulesDataInputEvaluator class. Therefore the abstract
 * methods prepare() and evaluate() have to be implemented, as well as access()
 * and help() could be overridden in order to control access permissions or to
 * provide some usage help.
 *
 * @return
 *   An array of information about the module's provided input evaluators. The
 *   array contains a sub-array for each evaluator, with the evaluator name as
 *   the key. The name may only contain lower case alpha-numeric characters and
 *   underscores and should be prefixed with the providing module name. Possible
 *   attributes for each sub-array are:
 *   - class: The implementation class, which has to extend the
 *     RulesDataInputEvaluator class. Required.
 *   - weight: A weight for controlling the evaluation order of multiple
 *     evaluators. Required.
 *   - type: Optionally, the data types for which the input evaluator should be
 *     used. Defaults to 'text'. Multiple data types may be specified using an
 *     array.
 *
 *  @see class RulesDataInputEvaluator
 *  @see hook_rules_evaluator_info_alter()
 */
function hook_rules_evaluator_info() {
  return array(
    'token' => array(
      'class' => 'RulesTokenEvaluator',
      'type' => array('text', 'uri'),
      'weight' => 0,
     ),
  );
}

/**
 * Declare provided rules data processors.
 *
 * The hook implementation should be placed into the file MODULENAME.rules.inc,
 * which gets automatically included when the hook is invoked.
 * For implementing a data processors a class has to be provided which
 * extends the abstract RulesDataProcessor class. Therefore the abstract
 * method process() has to be implemented, but also the methods form() and
 * access() could be overridden in order to provide a configuration form or
 * to control access permissions.
 *
 * @return
 *   An array of information about the module's provided data processors. The
 *   array contains a sub-array for each processor, with the processor name as
 *   the key. The name may only contain lower case alpha-numeric characters and
 *   underscores and should be prefixed with the providing module name, whereas
 *   'select' is reserved as well.
 *   Possible attributes for each sub-array are:
 *   - class: The implementation class, which has to extend the
 *     RulesDataProcessor class. Required.
 *   - weight: A weight for controlling the processing order of multiple data
 *     processors. Required.
 *   - type: Optionally, the data types for which the data processor should be
 *     used. Defaults to 'text'. Multiple data types may be specified using an
 *     array.
 *
 *  @see class RulesDataProcessor
 *  @see hook_rules_data_processor_info_alter()
 */
function hook_rules_data_processor_info() {
  return array(
    'date_offset' => array(
      'class' => 'RulesDateOffsetProcessor',
      'type' => 'date',
      'weight' => -2,
     ),
  );
}

/**
 * Alter rules compatible actions.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $actions
 *   The items of all modules as returned from hook_rules_action_info().
 *
 * @see hook_rules_action_info().
 */
function hook_rules_action_info_alter(&$actions) {
  // The rules action is more powerful, so hide the core action
  unset($actions['rules_core_node_assign_owner_action']);
  // We prefer handling saving by rules - not by the user.
  unset($actions['rules_core_node_save_action']);
}

/**
 * Alter rules conditions.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $conditions
 *   The items of all modules as returned from hook_rules_condition_info().
 *
 * @see hook_rules_condition_info()
 */
function hook_rules_condition_info_alter(&$conditions) {
  // Change conditions.
}

/**
 * Alter rules events.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $events
 *   The items of all modules as returned from hook_rules_event_info().
 *
 * @see hook_rules_event_info().
 */
function hook_rules_event_info_alter(&$events) {
  // Change events.
}

/**
 * Alter rules data types.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $data_info
 *   The items of all modules as returned from hook_rules_data_info().
 *
 * @see hook_rules_data_info()
 */
function hook_rules_data_info_alter(&$data_info) {
  // Change data types.
}

/**
 * Alter rules plugin info.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $plugin_info
 *   The items of all modules as returned from hook_rules_plugin_info().
 *
 * @see hook_rules_plugin_info()
 */
function hook_rules_plugin_info_alter(&$plugin_info) {
  // Change plugin info.
}

/**
 * Alter rules input evaluator info.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $evaluator_info
 *   The items of all modules as returned from hook_rules_evaluator_info().
 *
 * @see hook_rules_evaluator_info()
 */
function hook_rules_evaluator_info_alter(&$evaluator_info) {
  // Change evaluator info.
}

/**
 * Alter rules data_processor info.
 *
 * The implementation should be placed into the file MODULENAME.rules.inc, which
 * gets automatically included when the hook is invoked.
 *
 * @param $processor_info
 *   The items of all modules as returned from hook_rules_data_processor_info().
 *
 * @see hook_rules_data_processor_info()
 */
function hook_rules_data_processor_info_alter(&$processor_info) {
  // Change processor info.
}

/**
 * Act on rules configuration being loaded from the database.
 *
 * This hook is invoked during rules configuration loading, which is handled
 * by entity_load(), via classes RulesEntityController and EntityCRUDController.
 *
 * @param $configs
 *   An array of rules configurations being loaded, keyed by id.
 */
function hook_rules_config_load($configs) {
  $result = db_query('SELECT id, foo FROM {mytable} WHERE id IN(:ids)', array(':ids' => array_keys($configs)));
  foreach ($result as $record) {
    $configs[$record->id]->foo = $record->foo;
  }
}

/**
 * Respond to creation of a new rules configuration.
 *
 * This hook is invoked after the rules configuration is inserted into the
 * the database.
 *
 * @param RulesPlugin $config
 *   The rules configuration that is being created.
 */
function hook_rules_config_insert($config) {
  db_insert('mytable')
    ->fields(array(
      'nid' => $config->id,
      'plugin' => $config->plugin,
    ))
    ->execute();
}

/**
 * Act on a rules configuration being inserted or updated.
 *
 * This hook is invoked before the rules configuration is saved to the
 * database.
 *
 * @param RulesPlugin $config
 *   The rules configuration that is being inserted or updated.
 */
function hook_rules_config_presave($config) {
  if ($config->id && $config->owner == 'your_module') {
    // Add custom condition.
    $config->conditon(/* Your condition */);
  }
}

/**
 * Respond to updates to a rules configuration.
 *
 * This hook is invoked after the configuration has been updated in the
 * database.
 *
 * @param RulesPlugin $config
 *   The rules configuration that is being updated.
 */
function hook_rules_config_update($config) {
  db_update('mytable')
    ->fields(array('plugin' => $config->plugin))
    ->condition('id', $config->id)
    ->execute();
}

/**
 * Respond to rules configuration deletion.
 *
 * This hook is invoked after the configuration has been removed from the
 * database.
 *
 * @param RulesPlugin $config
 *   The rules configuration that is being deleted.
 */
function hook_rules_config_delete($config) {
  db_delete('mytable')
    ->condition('id', $config->id)
    ->execute();
}

/**
 * Respond to rules configuration execution.
 *
 * This hook is invoked right before the rules configuration is executed.
 *
 * @param RulesPlugin $config
 *   The rules configuration that is being executed.
 */
function hook_rules_config_execute($config) {

}

/**
 * Define default rules configurations.
 *
 * This hook is invoked when rules configurations are loaded. The implementation
 * should be placed into the file MODULENAME.rules_defaults.inc, which gets
 * automatically included when the hook is invoked.
 *
 * @return
 *   An array of rules configurations with the configuration names as keys.
 *
 * @see hook_default_rules_configuration_alter()
 * @see hook_rules_config_defaults_rebuild()
 */
function hook_default_rules_configuration() {
  $rule = rules_reaction_rule();
  $rule->label = 'example default rule';
  // Add rules tags.
  $rule->tags = array('Admin', 'Tag2');
  $rule->active = FALSE;
  $rule->event('node_update')
       ->condition(rules_condition('data_is', array('data:select' => 'node:status', 'value' => TRUE))->negate())
       ->condition('data_is', array('data:select' => 'node:type', 'value' => 'page'))
       ->action('drupal_message', array('message' => 'A node has been updated.'));

  $configs['rules_test_default_1'] = $rule;

  return $configs;
}

/**
 * Alter default rules configurations.
 *
 * The implementation should be placed into the file
 * MODULENAME.rules_defaults.inc, which gets automatically included when the
 * hook is invoked.
 *
 * @param $configs
 *   The default configurations of all modules as returned from
 *   hook_default_rules_configuration().
 *
 * @see hook_default_rules_configuration()
 */
function hook_default_rules_configuration_alter(&$configs) {
  // Add custom condition.
  $configs['foo']->condition('bar');
}

/**
 * Act after rebuilding default configurations.
 *
 * This hook is invoked by the entity module after default rules configurations
 * have been rebuilt; i.e. defaults have been saved to the database.
 *
 * @param $rules_configs
 *   The array of default rules configurations which have been inserted or
 *   updated, keyed by name.
 * @param $originals
 *   An array of original rules configurations keyed by name; i.e. the rules
 *   configurations before the current defaults have been applied. For inserted
 *   rules configurations no original is available.
 *
 * @see hook_default_rules_configuration()
 * @see entity_defaults_rebuild()
 */
function hook_rules_config_defaults_rebuild($rules_configs, $originals) {
  // Once all defaults have been rebuilt, update all i18n strings at once. That
  // way we build the rules cache once the rebuild is complete and avoid
  // rebuilding caches for each updated rule.
  foreach ($rules_configs as $name => $rule_config) {
    if (empty($originals[$name])) {
      rules_i18n_rules_config_insert($rule_config);
    }
    else {
      rules_i18n_rules_config_update($rule_config, $originals[$name]);
    }
  }
}

/**
 * Alter rules components before execution.
 *
 * This hooks allows altering rules components before they are cached for later
 * re-use. Use this hook only for altering the component in order to prepare
 * re-use through rules_invoke_component() or the provided condition/action.
 * Note that this hook is only invoked for any components cached for execution,
 * but not for components that are programmatically created and executed on the
 * fly (without saving them).
 *
 * @param $plugin
 *   The name of the component plugin.
 * @param $component
 *   The component that is to be cached.
 *
 * @see rules_invoke_component()
 */
function hook_rules_component_alter($plugin, RulesPlugin $component) {

}

/**
 * Alters event sets.
 *
 * This hooks allows altering rules event sets, which contain all rules that are
 * triggered upon a specific event. Rules internally caches all rules associated
 * to an event in an event set, which is cached for fast evaluation. This hook
 * is invoked just before any event set is cached, thus it allows altering of
 * the to be executed rules without the changes to appear in the UI, e.g. to add
 * a further condition to some rules.
 *
 * @param $event_name
 *   The name of the event.
 * @param $event_set
 *   The event set that is to be cached.
 *
 * @see rules_invoke_event()
 */
function hook_rules_event_set_alter($event_name, RulesEventSet $event_set) {

}

/**
 * D6 to D7 upgrade procedure hook for mapping action or condition names.
 *
 * If for a module the action or condition name changed since Drupal 6, this
 * "hook" can be implemented in order to map to the new name of the action or
 * condition.
 *
 * This is no real hook, but a callback that is invoked for each Drupal 6
 * action or condition that is to be upgraded to Drupal 7. E.g. the function
 * name called for the action "rules_action_set_node_title" would be
 * "rules_action_set_node_title_upgrade_map_name".
 *
 * @param $element
 *   The element array of a configured condition or action which is to be
 *   upgraded.
 * @return
 *   The name of the action or condition which should be used.
 */
function hook_rules_action_base_upgrade_map_name($element) {
  return 'data_set';
}

/**
 * D6 to D7 upgrade procedure hook for mapping action or condition configuration.
 *
 * During upgrading Drupal 6 rule configurations to Drupal 7 Rules is taking
 * care of upgrading the configuration of all known parameters, which only works
 * if the parameter name has not changed.
 * If something changed, this callback can be used to properly apply the
 * configuration of the Drupal 6 action ($element) to the Drupal 7 version
 * ($target).
 *
 * This is no real hook, but a callback that is invoked for each Drupal 6
 * action or condition that is to be upgraded to Drupal 7. E.g. the function
 * name called for the action "rules_action_set_node_title" would be
 * "rules_action_set_node_title_upgrade".
 *
 * @param $element
 *   The element array of a configured condition or action which is to be
 *   upgraded.
 * @param $target
 *   The Drupal 7 version of the configured element.
 *
 * @see hook_rules_element_upgrade_alter()
 */
function hook_rules_action_base_upgrade($element, RulesPlugin $target) {
  $target->settings['data:select'] = $element['#settings']['#argument map']['node'] . ':title';
  $target->settings['value'] = $element['#settings']['title'];
}

/**
 * D6 to D7 upgrade procedure hook for mapping action or condition configuration.
 *
 * A alter hook that is called after the action/condition specific callback for
 * each element of a configuration that is upgraded.
 *
 * @param $element
 *   The element array of a configured condition or action which is to be
 *   upgraded.
 * @param $target
 *   The Drupal 7 version of the configured element.
 *
 * @see hook_rules_action_base_upgrade()
 */
function hook_rules_element_upgrade_alter($element, $target) {

}

/**
 * Allows modules to alter or to extend the provided Rules UI.
 *
 * Use this hook over the regular hook_menu_alter() as the Rules UI is re-used
 * and embedded by modules. See rules_ui().
 *
 * @param $items
 *   The menu items to alter.
 * @param $base_path
 *   The base path of the Rules UI.
 * @param $base_count
 *   The count of the directories contained in the base path.
 */
function hook_rules_ui_menu_alter(&$items, $base_path, $base_count) {
  $items[$base_path . '/manage/%rules_config/schedule'] = array(
    'title callback' => 'rules_get_title',
    'title arguments' => array('Schedule !plugin "!label"', $base_count + 1),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('rules_scheduler_schedule_form', $base_count + 1, $base_path),
    'access callback' => 'rules_config_access',
    'access arguments' => array('update', $base_count + 1),
    'file' => 'rules_scheduler.admin.inc',
    'file path' => drupal_get_path('module', 'rules_scheduler'),
  );
}

/**
 * Control access to Rules configurations.
 *
 * Modules may implement this hook if they want to have a say in whether or not
 * a given user has access to perform a given operation on a Rules
 * configuration.
 *
 * @param $op
 *   The operation being performed. One of 'view', 'create', 'update' or
 *   'delete'.
 * @param $rules_config
 *   (optional) A Rules configuration to check access for. If nothing is given,
 *   access for all Rules configurations is determined.
 * @param $account
 *   (optional) The user to check for. If no account is passed, access is
 *   determined for the current user.
 * @return boolean
 *   Return TRUE to grant access, FALSE to explicitly deny access. Return NULL
 *   or nothing to not affect the operation.
 *   Access is granted as soon as a module grants access and no one denies
 *   access. Thus if no module explicitly grants access, access will be denied.
 *
 * @see rules_config_access()
 */
function hook_rules_config_access($op, $rules_config = NULL, $account = NULL) {
  // Instead of returning FALSE return nothing, so others still can grant
  // access.
  if (isset($rules_config) && $rules_config->owner == 'mymodule' && user_access('my modules permission')) {
    return TRUE;
  }
}

/**
 * @}
 */