Extra Category Meta

extra-category-meta.php

<?php
// put that into functions.php or include via functions.php

define( 'RG_LOCALE', 'rg_locale' );

add_action( 'edit_category_form_fields', 'rgicgier_category_custom_fields', 10, 2 );
add_action( 'edited_category', 'rgicgier_save_category_fields', 10, 2 );

/**
 * Facilitate obtaining of category meta
 * 
 * @param int $term_id
 * @return array
 * @throws Exception 
 */
function rgicgier_get_category_meta($term_id = null) {
	if ( null === $term_id ) {
		if ( is_category() ) {
			$term_id = get_cat_id( single_cat_title( "", false ) );
			$meta = get_option( "category_$term_id" );
			return $meta;
		} else {
			throw new Exception( __( 'Use this hook on a category page or pass term id' ) );
		}
	} else {
		$meta = get_option( "category_$term_id" );
		return $meta;
	}
}


/**
 * Print custom form fields
 * 
 * @param object $tag 
 */
function rgicgier_category_custom_fields($tag) {

	$t_id = $tag->term_id; // Get the ID of the term being edited
	$category_meta = get_option( "category_$t_id" );
	?>

	<tr valign="top">
		<th scope="row"><?php _e( 'Sidebar Display', RG_LOCALE ); ?></th>
		<td> <fieldset><legend class="screen-reader-text"><span>Sidebar display</span></legend><label for="sidebar_display">
					<input type="checkbox" id="sidebar_display" name="category_meta[sidebar_display]" <?php checked( isset( $category_meta['sidebar_display'] ) && $category_meta['sidebar_display'] !== 'off' ) ?>>
					<?php _e( 'Checked displays sidebar on the category page', RG_LOCALE ); ?></label>
			</fieldset>
		</td>
	</tr>
	<?php
}


/**
 * Save custom category fields
 * 
 * @param id $term_id 
 */
function rgicgier_save_category_fields($term_id) {
	// make sure that the user has the right privileges
	if ( current_user_can( 'manage_categories' ) ) {
		$t_id = $term_id;

		$term_meta = get_option( "category_$t_id" ); // load the old data from the db
		// hardcoded, warning !
		$checkbox_key = 'sidebar_display';

		if ( !isset( $_POST['category_meta'][$checkbox_key] ) ) {
			$term_meta[$checkbox_key] = 'off';
		} else {
			$term_meta[$checkbox_key] = 'on';
		}

		// Note we check to see if the option exists so we get a chance to
		// call add_option with the autoload argument. This is an ugly
		// aspect of WordPress. This is a performance consideration, to
		// prevent WordPress from needlessly querying these options with
		// every request.
		// See http://codex.wordpress.org/Function_Reference/update_option
		$not_exists = false;
		$autoload = 'no';
		$option_name = "category_$t_id";
		$existing_option = get_option( $option_name, $not_exists );
		if ( $existing_option === $not_exists ) {
			add_option( $option_name, $term_meta, null, $autoload );
		} else {
			update_option( $option_name, $term_meta );
		}
	} else {
		wp_die( __( 'Sorry you\'ve got no rights to edit that page', RG_LOCALE ) );
	}
}

// lack of closing tag, see http://php.net/manual/en/language.basic-syntax.instruction-separation.php