Custom Metadata Manager

An easy way to add custom fields to your object types (post, pages, custom post types, users) & to generate option pages.

The goal of this plugin is to help you rapidly build familiar, intuitive interfaces for your users in a very WordPress-native way.

The custom field panel is nice, but not quite the easiest thing for users to work with. Adding your own metaboxes and fields involves a lot of time and repetitive code that could be better used elsewhere.

This plugin handles all that heavy-lifting for you behind-the-scenes, so that you can focus on more on building out and connecting your data rather than all the minor details. This single piece of code x_add_metadata_field( 'my-field-name', 'post' ); generates a metabox with a text field inside it, with the necessary hooks to save the entered values.

The API is similar to that used for registering custom post types and taxonomies so it should be familiar territory.

NOTE: The plugin now requires WordPress 3.3+ (chiefly for the wysiwyg & datepicker fields)

Like what you see? Want more field types and features added? Get in touch or contribute on github

See “Other Notes” section for usage information

Usage

Object Types

The main idea behind this plugin is to have a single API to work with regardless of the object type. Currently, Custom Metadata Manager works with user, comment and any built-in or custom post types, e.g. post, page, etc.

Registering your fields

For the sake of performance (and to avoid potential race conditions), always register your custom fields in the admin_menu hook. This way your front-end doesn’t get bogged down with unnecessary processing and you can be sure that your fields will be registered safely. Here’s a code sample:

add_action( 'admin_menu', 'my_theme_init_custom_fields' );

function my_theme_init_custom_fields() {
    if( function_exists( 'x_add_metadata_field' ) && function_exists( 'x_add_metadata_group' ) ) {
        x_add_metadata_field( 'my_field', array( 'user', 'post' ) );
    }
}

Getting the data

You can get the data as you normally would using the get_metadata function. Custom Metadata manager stores all data using the WordPress metadata APIs using the slug name you provide. That way, even if you decide to deactivate this wonderful plugin, your data is safe and accessible. For options, you can use get_option.

Example:

$value = get_metadata( 'post', get_the_ID(), 'featured', true ); // Returns post metadata value for the field 'featured'

Adding Metadata Groups

A group is essentially a metabox that groups together multiple fields. Register the group before any fields

x_add_metadata_group( $slug, $object_types, $args );

Parameters

• $slug (string) The key under which the metadata will be stored.
• $object_types (string|array) The object types to which this field should be added. Supported: post, page, any custom post type, user, comment.

Options and Overrides

$args = array(
    'label' => $group_slug, // Label for the group
    'context' => 'normal', // (post only)
    'priority' => 'default', // (post only)
    'autosave' => false, // (post only) Should the group be saved in autosave? NOT IMPLEMENTED YET!
    'exclude' => '', // see below for details
    'include' => '', // see below for details
);

Adding Metadata Fields

x_add_metadata_field( $slug, $object_types, $args );

Parameters

• $slug (string) The key under which the metadata will be stored. For post_types, prefix the slug with an underscore (e.g. _hidden) to hide it from the the Custom Fields box.
• $object_types (string|array) The object types to which this field should be added. Supported: post, page, any custom post type, user, comment.

Options and Overrides

$args = array(
    'group' => '', // The slug of group the field should be added to. This needs to be registered with x_add_metadata_group first.
    'field_type' => 'text', // The type of field; 'text', 'textarea', 'password', 'checkbox', 'radio', 'select', 'upload', 'wysiwyg', 'datepicker', 'taxonomy_select', 'taxonomy_radio'
    'label' => '', // Label for the field
    'description' => '', // Description of the field, displayed below the input
    'values' => array(), // Values for select and radio buttons. Associative array
    'display_callback' => '', // Callback to custom render the field
    'sanitize_callback' => '', // Callback to sanitize data before it's saved
    'display_column' => false, // Add the field to the columns when viewing all posts
    'display_column_callback' => '', // Callback to render output for the custom column
    'required_cap' => '', // The cap required to view and edit the field
    'exclude' => '', // see below for details
    'include' => '', // see below for details
    'multiple' => false, // true or false, can the field be duplicated with a click of a button?
    'readonly' => false, // makes the field be readonly (works with text, textarea, password, upload and datepicker fields)
);

Include / Exclude

You can exclude fields and groups from specific object. For example, with the following, field-1 will show up for all posts except post #123:

$args = array(
    'exclude' => 123
);
x_add_metadata_field( 'field-1', 'post', $args );

Alternatively, you can limit (“include”) fields and groups to specific objects. The following will ”only” show group-1 to post #456:

$args = array(
    'include' => 123
);
x_add_metadata_group( 'group-1', 'post', $args );

You can pass in an array of IDs:

$args = array(
    'include' => array( 123, 456, 789 );
);

With multiple object types, you can pass in an associative array:

$args = array(
‘exclude’ => array(
‘post’ => 123,
‘user’ => array( 123, 456, 789 )
)
);

Examples

For examples, please see the custom_metadata_examples.php file included with the plugin. Add a constant to your wp-config.php called CUSTOM_METADATA_MANAGER_DEBUG with a value of true to see it in action:

define( 'CUSTOM_METADATA_MANAGER_DEBUG', true );

TODOs

Stuff we have planned for the future:

• Ability to clone (multiple) groups of fields
• Ability Pass in attributes for built-in fields (e.g. class, data-*, etc.)
• Additional field types (multi-select, multi-checkbox)
• Limit or exclude groups and fields using a custom callback
• Autosave support for fields on post types
• Client- and server-side validation support
• Add groups and fields to Quick Edit