SF Meta Archives

SF Meta Archives is a plugin for WordPress. It gives you the hability to have archive pages for your post metas. It should be used as a Must-Use plugin (but it works as a regular plugin too of course). For more details, see http://www.screenfeed.fr/regpm (french).

You have 2 kinds of archive:

• "Post-type-like" type: an archive with an url like http://example.com/my-meta/
• "Taxonomy-like" type: an archive with an url like http://example.com/my-meta/my-value/

4 functions to use

register_post_meta( $meta_name, $args ): Register the post metas.

@param (string) $meta_name The name of your post meta.

@param (array|object) $args Arguments:

post_type (string|array) Post types. Optional.

query_var (string) Used as query variable name: instead of "$meta_name = ...", "$query_var = ..." will be used. Optional, fallback to $meta_name.

query_value (bool) Set to true if you want a "Taxonomy-like" architecture.

meta_query (array) Takes an array of meta query arguments arrays (it takes an array of arrays). See WP_Query. Required for "Post-type-like".

rewrite (bool|array) Array of parameters for rewrite (or true/false): slug, with_front, feeds, pages, ep_mask. See register_post_type(). Optional.

label (string) Used to filter the wp_title() function for the archive title. Optional, but should be used.

description (string) Do I really have to explain what is it for? Optional.

is_post_meta_archive( $query_var = null, $query_value = null ): Is a meta archive displaying?

@param (string) $query_var See register_post_meta(). Optional.

@param (string) $query_value For "Taxonomy-like", can be used to check against a precise meta value. Optional.

@return (bool)

get_post_meta_archive_link( $query_var, $meta_value = null, $paged = 1 ): Url of a meta archive.

@param (string) $query_var See register_post_meta(). Required.

@param (string) $query_value The meta value. Required for "Taxonomy-like".

@param (int) $paged Page 1, page 2... Optional.

@return (string) The url of the archive page.

get_post_meta_archive_description( $query_var = null, $query_value = null ): Description of a meta archive.

@param (string) $query_var See register_post_meta(). Fallback to the current archive value.

@param (string) $query_value For a "taxonomy-like" archive, you can specify a value: if the description contains "%s", the value will be used. Fallback to the current archive value.

@return (string) The description of the archive page.

Examples

An archive page listing all Posts having a thumbnail ("Post-type-like")

add_action( 'after_setup_theme', 'register_posts_with_thumb_archive' );
 
function register_posts_with_thumb_archive() {
	$args = array(
		'query_var'		=> 'with-thumb',
		'meta_query'	=> array(
			array(
				'key'		=> '_thumbnail_id',
				'compare'	=> 'EXISTS',
			),
		),
		'title'	 		=> __( 'Posts with a thumbnail' ),
		'description'	=> __( 'All my Posts with a thumbnail.' ),
	);
	register_post_meta( '_thumbnail_id', $args );
}

But, it can be even simpler (if key is not provided in meta_query, $meta_name will be used automatically):

add_action( 'after_setup_theme', 'register_posts_with_thumb_archive' );
 
function register_posts_with_thumb_archive() {
	$args = array(
		'query_var'		=> 'with-thumb',
		'title'	 		=> __( 'Posts with a thumbnail' ),
		'description'	=> __( 'All my Posts with a thumbnail.' ),
	);
	register_post_meta( '_thumbnail_id', $args );
}

To know if we're displaying a meta archive:

if ( is_post_meta_archive( 'with-thumb' ) ) {
	// ...
}

Display a link to the archive:

<a href="<?php echo get_post_meta_archive_link( 'with-thumb' ); ?>"><?php _e( 'Posts with a thumbnail' ); ?></a>

The URL will be http://example.com/with-thumb/ or http://example.com?meta=with-thumb.

Display the description of an archive:

echo wpautop( get_post_meta_archive_description( 'with-thumb' ) );

This will print <p>All my Posts with a thumbnail.</p>.

An archive page listing events by city ("Taxonomy-like")

In this case, "event" is a Custom Post Type, "_city" is a post meta.

add_action( 'after_setup_theme', 'register_events_city_archive' );
 
function register_events_city_archive() {
	$args = array(
		'post_type' 	=> 'event',
		'query_var' 	=> 'city',
		'query_value'	=> true,
		'meta_query'	=> array(
			array(
				'key'		=> '_city',
				'value'		=> '',
				'compare'	=> '!=',
			),
		),
		'title' 		=> __( 'Events by city' ),
		'description'	=> __( 'Events in %s.' ),
	);
	register_post_meta( '_city', $args );
}

To know if we're displaying a meta archive (any one):

if ( is_post_meta_archive( 'city' ) ) {
	// ...
}

or the one for "paris":

if ( is_post_meta_archive( 'city', 'paris' ) ) {
	// ...
}

Display a link to an archive:

<a href="<?php echo get_post_meta_archive_link( 'city', 'paris' ); ?>">Paris</a>

The URL will be http://example.com/city/paris/ or http://example.com?city=paris.

Display the description of an archive:

echo wpautop( get_post_meta_archive_description( 'city', 'paris' ) );

This will print <p>Events in paris.</p>.

In this situation, be aware of one thing: you may not want to deal with space caracters or uppercase letters… But the good news is there's enough filters and actions in the plugin to do what you may want.