Filters terms lookup to set the post format.

Signature

_wp_preview_terms_filter( $terms, $post_id, $taxonomy )
terms
 
post_id
 
taxonomy
 

Return

(void)

Source

function _wp_preview_terms_filter( $terms, $post_id, $taxonomy ) {
	if ( ! $post = get_post() )
		return $terms;

	if ( empty( $_REQUEST['post_format'] ) || $post->ID != $post_id || 'post_format' != $taxonomy || 'revision' == $post->post_type )
		return $terms;

	if ( 'standard' == $_REQUEST['post_format'] )
		$terms = array();
	elseif ( $term = get_term_by( 'slug', 'post-format-' . sanitize_key( $_REQUEST['post_format'] ), 'post_format' ) )
		$terms = array( $term ); // Can only have one post format

	return $terms;
}
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