README

WordPress library that enables direct relationships for posts to posts and posts to users.

Installation and Usage

WP Content Connect can be used as a plugin or a standalone library. The easiest way to use this is to install as a plugin and activate.

Composer install

As a library

First, require this repository using the command line:

$ composer require 10up/wp-content-connect

or directly in composer.json:

  "require": {
    "10up/wp-content-connect": "^1.5.0"
  }

This will install WP Content Connect to your vendor folder and allow you to to use it as a library by calling \TenUp\ContentConnect\Plugin::instance(); from your code.

As a plugin

Alternatively, if you prefer to have composer install it as a plugin, you may redeclare this package in your composer.json using the following example:

{
  "name": "your project name",
  "repositories": [
    {
      "type": "package",
      "package": {
        "name": "10up/wp-content-connect",
        "type": "wordpress-plugin",
        "version": "1.5.0",
        "source": {
          "url": "https://github.com/10up/wp-content-connect.git",
          "type": "git",
          "reference": "1.5.0"
        }
      }
    }
  ],
  "require": {
    "10up/wp-content-connect": "^1.5",
    "composer/installers": "^1.7"
  },
  "extra": {
    "installer-paths": {
      "plugins/wp-content-connect/": [
        "10up/wp-content-connect"
      ]
    }
  }
}

Defining Relationships

Relationships can be defined once any post types they utilize are defined by hooking into the tenup-content-connect-init action. This action is fired on the WordPress init action, at priority 100, so any post types must be registered prior to this. Currently supported relationships are post-to-post and post-to-user. Additionally, when registering a relationship, you must specify a name. Name enables multiple distinct relationships between the same object types. For instance, you could have a post-to-user relationship for post type post with a type of researchers to indicate that any user in the "researcher" relationship is a researcher for the post and have another post-to-user relationship defined for post type post with a name of backer to indicate that any user in the "backer" relationship contributes financially to the post.

define_post_to_post( $from, $to, $name, $args = array() )

This method defines a post to post relationship between two post types, $from and $to.

Parameters:

$from (String) First post type in the relationship

$to (String|Array) Second post type(s) in the relationship

$name (String) Unique name for this relationship, used to distinguish between multiple relationships between the same post types

$args (Array) Array of options for the relationship

Args:

Args expects options for the from and to sides of the relationship as top level keys. Options for each direction are as follows:

• enable_ui (Bool) - Should the default UI be enabled for the current side of this relationship
• sortable (Bool) - Should the relationship be sortable for the current side of this relationship
• labels (Array) - Labels used in the UI for the relationship. Currently only expects one value, name (String)

Return Value

This method returns an instance of \TenUp\ContentConnect\Relationships\PostToPost specific to this relationship. The object can then be used to manage related items manually, if required. See the <@TODO insert link> section below.

Example:

function my_define_relationships( $registry ) {
    $args = array(
        'from' => array(
            'enable_ui' => true,
            'sortable' => true,
            'labels' => array(
                'name' => 'Related Tires',
            ),
        ),
        'to' => array(
            'enable_ui' => false,
            'sortable' => false,
            'labels' => array(
                'name' => 'Related Cars',
            ),
        ),
    );

    $relationship = $registry->define_post_to_post( 'car', 'tire', 'car-tires', $args );    
}
add_action( 'tenup-content-connect-init', 'my_define_relationships' );

define_post_to_user( $post_type, $name $args = array() )

This method defines a post to user relationship between the supplied post type and users.

Parameters:

$post_type (String) The post type to be related to users

$name (String) Unique name for this relationship, used to distinguish between multiple relationships between users and the same post type

$args (Array) Array of options for the relationship

Args:

Args expects options for the from (post type) side of the relationship as a top level key. Options are as follows:

• enable_ui (Bool) - Should the default UI be enabled for the current side of this relationship
• sortable (Bool) - Should the relationship be sortable for the current side of this relationship
• labels (Array) - Labels used in the UI for the relationship. Currently only expects one value, name (String)

Return Value

This method returns an instance of \TenUp\ContentConnect\Relationships\PostToUser specific to this relationship. The object can then be used to manage related items manually, if required. See the <@TODO insert link> section below.

Example:

function my_define_relationships( $registry ) {
    $args = array(
        'from' => array(
            'enable_ui' => true,
            'sortable' => false,
            'labels' => array(
                'name' => 'Related Users',
            ),
        ),
    )
    
    $relationship = $registry->define_post_to_user( 'post', 'related', $args );   
}
add_action( 'tenup-content-connect-init', 'my_define_relationships' );

There is not currently support for rendering any default UIs on the User side of these relationships

Sortable Relationships

Relationships can optionally support sortable related items. Order can be stored independently for both sides of a relationship. For example, if you have cars and tires, you may have a car that has 5 related tires, and if you wanted to sort the tires, you do so from the car page. You could then go to one of the related tires, and order all of the cars it is related to separately.

Since you can manage this relationship from both post types in the relationship, if you added a tire from the car page, and you had relationship data previously stored on the tire, the NEW car in the relationship will still show up in query results, at the very end (after all of your other pre-ordered data).

Query Integration

Querying for relationships is enabled via a new relationship_query parameter for WP_Query. The format for relationship_query is very similar to tax_query.

A valid relationship query segment requires name and either related_to_post OR related_to_user. As many relationship segments as necessary can be combined to create a specific set of results, and can be combined using an AND or OR relation.

Top Level Args:

• relation (String) Can be either AND (default) or OR. How all of the segments in the relationship should be combined.

Segment Args:

• name (String) The unique name for the relationship you are querying. Should match a name from registering relationships.
• related_to_post (Int) Find items in the relationship related to this post ID. Cannot be used in the same segment as related_to_user.
• related_to_user (Int) Find items in the relationship related to this user ID. Cannot be used in the same segment as related_to_post.

Example:

$query = new WP_Query( array(
    'post_type' => 'post',
    'relationship_query' => array(
        'relation' => 'AND', // AND is default
        array(
            'related_to_post' => 25,
            'name' => 'related',
        ),
        array(
            'related_to_user' => 5,
            'name' => 'researcher',
        )
    ),
) );

Currently, querying for multiple post types in WP_Query may not work as expected. When using relationship queries, make sure to only have one post_type value in WP_Query.

Order By

For relationships where sorting is disabled, all of the default WP_Query orderby options are supported. In addition to default orderby options, if sorting is enabled for a relationship, an additional orderby parameter relationship is supported. When using relationship as the orderby value, the order is always ASC and you must adhere to the following WP_Query and WP_User_Query restrictions:

• Compound relationship queries are not allowed - only one segment may be added to the query

For example, this is fine:

'relationship_query' => array(
    array(
        'related_to_post' => 25,
        'name' => 'related',
    ),
),
'orderby' => 'relationship',

while this will not work (orderby will be ignored):

'relationship_query' => array(
    array(
        'related_to_post' => 25,
        'name' => 'related',
    ),
    array(
		'related_to_post' => 15,
		'name' => 'related',
	),
),
'orderby' => 'relationship',

Manually Managing Relationships

If you choose to not use the built in UIs for relationships, you'll need to manually update relationships. DO NOT try and work directly with the database tables. Instead, work with the following API methods. The underlying implementations may need to change from time to time, but the following methods should continue to function if the underlying implementations need to change.

These methods are available on the relationship objects returned when defining the relationship. Make sure to call these methods on the specific relationship object you are defining a relationship for, as these methods are specific to the relationship context (they are aware of the name of the relationship, as well as the post types in the relationship).

If you don't already have a relationship object, you can get one from the registry using either Registry->get_post_to_post_relationship() or Registry->get_post_to_user_relationship().

Registry->get_post_to_post_relationship( $cpt1, $cpt2, $name )

Returns the relationship object between the two post types with the provided name.

Parameters:

$cpt1 (String) The first post type in the relationship

$cpt2 (String) The second post type in the relationship

$name (String) The name of the relationship, as passed to define_post_to_post_relationship

Example:

$registry = \TenUp\ContentConnect\Plugin::instance()->get_registry();

// Gets the car to tire relationship defined in the example above
$relationship = $registry->get_post_to_post_relationship( 'car', 'tire', 'car-tires' );

Registry->get_post_to_user_relationship( $post_type, $name )

Returns the relationship object between the post types and users with the provided name.

Parameters:

$post_type (String) The post type in the post to user relationship

$name (String) The name of the relationship, as passed to define_post_to_user_relationship

Example:

$registry = \TenUp\ContentConnect\Plugin::instance()->get_registry();

// Gets the post to user relationship defined in the example above
$relationship = $registry->get_post_to_user_relationship( 'post', 'related' );

PostToPost->add_relationship( $pid1, $pid2 )

This method adds a relationship between one post and another, in a post to post relationship. When calling this method, the order of IDs passed is not important.

Parameters:

$pid1 (Int) The ID of the first post in the relationship

$pid2 (Int) The ID of the second post in the relationship

Example:

// $relationship is the return value from ->define_post_to_post()
$relationship->add_relationship( 1, 2 ); // Adds a relationship between post ID 1 and post ID 2

PostToPost->delete_relationship( $pid1, $pid2 )

This methods deletes a relationship between one post and another, in a post to post relationship. When calling this method, the order of IDs passed is not important.

Parameters:

$pid1 (Int) The ID of the first post in the relationship. Does not need to be in the same order as the relationship was added.

$pid2 (Int) The ID of the second post in the relationship. Does not need to be in the same order as the relationship was added.

Example:

// $relationship is the return value from ->define_post_to_post()
// Note that the example above added these in the reverse order, but the relationship is still deleted
$relationship->delete_relationship( 2, 1 ); // Deletes the relationship between post ID 1 and post ID 2. 

PostToPost->replace_relationships( $post_id, $related_ids )

Replaces existing relationships for the post to post relationship. Any relationship that is present in the database but not in $related_ids will no longer be related.

Parameters:

$post_id (Int) The ID of the post we are replacing relationships from.

$related_ids (Array) An array of Post IDs of items related to $post_id

Example:

Post ID 5 is related to posts 2, 3, 6, 7, 8

// $relationship is the return value from ->define_post_to_post()
$relationship->replace_relationships( 5, array( 2, 3, 6, 7, 8 ) );

PostToPost->save_sort_data( $object_id, $ordered_ids )

For a relationship with sorting enabled, this saves the order of the posts for a single direction of the relationship.

Parameters:

$object_id (Int) The Post ID that we are ordering from. If we were ordering 5 tires for a single car, this would be the car ID.

$ordered_ids (Array) An array of Post IDs, in the order they should be sorted. If we were ordering 5 tires for a single car, this is the ordered tire IDs.

Example:

Car ID 5 has five related tires, that should be ordered 7, 6, 3, 8, 2

// $relationship is the return value from ->define_post_to_post()
$relationship->save_sort_data( 5, array( 7, 6, 3, 8, 2 ) );

PostToUser->add_relationship( $post_id, $user_id )

This method adds a relationship between a post and a user, in a post to user relationship.

Parameters:

$post_id (Int) The ID of the post in the relationship

$user_id (Int) The ID of the user in the relationship

Example:

// $relationship is the return value from ->define_post_to_user()
$relationship->add_relationship( 1, 5 ); // Adds a relationship between post 1 and user 5

PostToUser->delete_relationship( $post_id, $user_id )

This method deletes a relationship between a post and a user, in a post to user relationship.

Parameters:

$post_id (Int) The ID of the post in the relationship

$user_id (Int) The ID of the user in the relationship

Example:

// $relationship is the return value from ->define_post_to_user()
$relationship->delete_relationship( 1, 5 ); // Deletes the relationship between post 1 and user 5

PostToUser->replace_post_to_user_relationships( $post_id, $user_ids )

Replaces users related to a post with the provided set of user ids. Any users related to the post that are not provided in $user_ids will no longer be related.

Parameters:

$post_id (Int) The ID of the post we are replacing relationships from.

$user_ids (Array) An array of User IDs related to $post_id

Example:

Post ID 5 is related to users 3, 4, 5

// $relationship is the return value from ->define_post_to_user()
$relationship->replace_post_to_user_relationships( 5, array( 3, 4, 5 ) );

PostToUser->replace_user_to_post_relationships( $user_id, $post_ids )

Replaces posts related to a user with the provided set of post ids. Any posts related to the user that are not provided in $post_ids will no longer be related.

Parameters:

$user_id (Int) The User ID we are replacing relationships from.

$post_ids (Array) An array of Post IDs related to $user_id

Example:

User 2 is related to posts 6, 7, 8

// $relationship is the return value from ->define_post_to_user()
$relationship->replace_user_to_post_relationships( 2, array( 6, 7, 8 ) );

PostToUser->save_post_to_user_sort_data( $object_id, $ordered_user_ids )

For a relationship with sorting enabled, this saves the order of users for a particular post

Parameters:

$object_id (Int) The ID of the post to store the order of users for

$ordered_user_ids (Array) Array of User IDs, in the order they should be sorted.

Example:

Post ID has 5 users that need to be stored in the following order: 2, 4, 1, 6, 3

// $relationship is the return value from ->define_post_to_user()
$relationship->save_post_to_user_sort_data( 5, array( 2, 4, 1, 6, 3 ) );

PostToUser->save_user_to_post_sort_data( $user_id, $ordered_post_ids )

For a relationship with sorting enabled, this saves the order of posts for a particular user

Parameters:

$user_id (Int) The ID of the user to store the order of posts for

$ordered_post_ids (Array) Array of Post IDs, in the order they should be sorted

Example:

User ID 1 has 5 posts that need to be stored in the following order: 4, 2, 7, 9, 8

// $relationship is the return value from ->define_post_to_user()
$relationship->save_user_to_post_sort_data( 1, array( 4, 2, 7, 9, 8 ) );

Support Level

Stable: 10up is not planning to develop any new features for this, but will still respond to bug reports and security concerns. We welcome PRs, but any that include new features should be small and easy to integrate and should not include breaking changes. We otherwise intend to keep this tested up to the most recent version of WordPress.

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