Filtering posts by post meta data

Question

I want to filter posts in such a way that only posts, for which get_post_meta($post->ID, "project_cat", true) (it returns a post ID) is equal to my specified value, are shown.

Any way to do this?

I am especially interested in ways to do it compatible with WP-Paginate plugin.

Answer 1

The WP_Query object accepts a post meta argument. Generally speaking you want to do the following:

  $my_query = new WP_Query( 
    array(
      'post_type' => 'post',
      'meta_query' => array(
        array(
          'key' => 'project_cat',
          'value' => 'my-value',
        )
      ),

        // Other query properties
    ) 
  );

Where 'my-value' is your 'specified value'.

Example usage:

  add_action( 'pre_get_posts' , 'my_pre_get_posts' );

  function my_pre_get_posts( $query ) {

    // Check this is main query and other conditionals as needed
    if( $query->is_main_query() ) {
        $query->set( 
          'meta_query', 
          array( 
            array(
              'key' => 'project_cat',
              'value' => 'my-value'
            )
          )
        );
    }

  }

See WP_Query, pre_get_posts. All conditionals are available to you. Currently this runs on every main query - which you probably don't want.

Alternatively you can use query_posts (a simpler, but much less efficient way) to alter the query for only a specific instance in a template.

Answer 2

you can filter the post based on the meta value and display the post on the cms page.

'meta_query' => array(
        array(
            'key'     => 'front_page',
            'value'   => 'yes',
            'compare' => 'LIKE',
        ))

please refer the tutorial for step by step explanation

http://www.pearlbells.co.uk/filter-posts-custom-fields-wp_query/