How Press This Works

If you log into WordPress and navigate to Settings -> Writing you will find a heading for “Press This” which instructs you to drag a link into the bookmarks bar in your browser. What you are bookmarking is not really a link but a small javascript application known as a bookmarklet. You can now navigate to any webpage and when you click your Press This bookmarklet a popup window will open which displays a form allowing you to publish a post about the page. What impressed me here is that certain fields are already filled out:

1. The title tag of the html document is inserted as the value of the post title.
2. If any text was selected, it is inserted into the content box
3. A link to the document is appended to the content box.

What I Need to Do

1. I need to create a bookmark and not a post.
2. I need to automatically set the title.
3. I need all custom taxonomies to display.
4. I need to set the name and value of a custom field.

On my site I have one custom post_type registered (mfields_bookmark) which I use to archive interesting articles about web development that I have read. Unfortunately, Press This only seems to enable you to create “posts”. My initial idea was to create a custom popup window by copying the code from press-this.php into a custom function which would be triggered via admin-ajax.php. Seemed like a good idea, but it also sounded like a lot of work! After thinking about it, I really didn’t need the popup window, I would be happy if my bookmarklet just opened post-new.php in a new tab. So I started hacking post-new.php's query string to see if the post form would recognize any values… And it did!

Post Title

The post title can be injected by setting a value to post_title. Something Like this works rather well: /wp-admin/post-new.php?post_title=TITLE

Although, I will not need to set the content here, I found that it can easily be set in much the same way: /wp-admin/post-new.php?content=CONTENT

Custom Field

I only need one custom field to be defined for a bookmark post to function properly. I couldn’t find any hooks that I could use in core so I decided to try a bit of javascript. I came up with the following code which I added to my theme’s functions.php file:

add_action( 'admin_head-post-new.php', 'mfields_process_bookmark_bookmarklet' );

function mfields_process_bookmark_bookmarklet() {
	global $post;
	if ( isset( $post->post_type ) && 'mfields_bookmark' === $post->post_type && isset( $_GET['mfields_bookmark_url'] ) ) {
		$url = esc_url( $_GET['mfields_bookmark_url'] );
		print <<< EOF
		<script type="text/javascript">
		jQuery( document ).ready( function ( $ ) {
			$( '#metakeyselect' ).val( 'resource_url' );
			$( '#metavalue' ).text( '{$url}' );
		} );
		</script>
EOF;
	}
}

This function will fire during the admin_head action on post-new.php for the mfields_bookmark post_type. If mfields_bookmark_url is defined in the query string, the function will automatically select it as the name from the select box. Likewise, the value of mfields_bookmark_url will be used as the value of the custom field.

Creating the Bookmarklet

Now that WordPress has been configured to recognize this custom information, I needed to create an easy way of sending it. I copied the Press This javascript and reworked it to talk to post-new.php.

javascript:(
	function(){
		var title = encodeURIComponent( document.title ),
		bookmark = encodeURIComponent( document.location.href ),
		url = 'http://example.com/wp-admin/post-new.php?post_type=mfields_bookmark&mfields_bookmark_url=' + bookmark + '&post_title=' + title;
		window.open(url);
	}
)();

Basically when you call this function, it will open post-new.php in a new tab sending the title and url of the document you were just viewing as well as setting the value of post_type to mfields_bookmark.

Adding this code to your browser is simple. In Chrome you can right-click the bookmarks toolbar and select Add Page…. Type “Bookmark This” as the name and use the javascript as the url. It might be a good idea to have the script on one line like this:

javascript:(function(){ var title = encodeURIComponent( document.title ), bookmark = encodeURIComponent( document.location.href ), url = 'http://example.com/wp-admin/post-new.php?post_type=mfields_bookmark&mfields_bookmark_url=' + bookmark + '&post_title=' + title; window.open(url); })();

I hope that someone out there finds this useful. I’m pretty excited about it as it will really cut down the steps involved in posting bookmarks on my site.

if( !function_exists( 'mfields_taxonomy_add_term_row_actions' ) ) {
	add_action( 'admin_init', 'mfields_taxonomy_add_term_row_actions' );
	/**
	 * Dynamically create actions for every defined taxonomy.
	 */
	function mfields_taxonomy_add_term_row_actions() {
		global $wp_taxonomies;
		foreach( $wp_taxonomies as $taxonomy => $taxonomies ) {
			$action = 'manage_' . $taxonomy . '_custom_column';
			add_action( $action, 'your_function_name', 10, 3 );
		}
	}
}

Shorten the Term Descriptions

/**
 * Create actions for all taxonomies.
 *
 * @return    void
 *
 * @since     2010-05-31
 * @alter     2011-01-09
 */
function mfields_taxonomy_description_add_actions() {
	global $wp_taxonomies;
	foreach ( $wp_taxonomies as $taxonomy => $taxonomies ) {
		add_action( 'manage_' . $taxonomy . '_custom_column', 'mfields_taxonomy_description_rows', 10, 3 );
		add_action( 'manage_edit-' . $taxonomy . '_columns',  'mfields_taxonomy_description_columns' );
	}
}
add_action( 'admin_init', 'mfields_taxonomy_description_add_actions' );

/**
 * Filter the taxonomy tables columns.
 *
 * Remove the default "Description" column.
 * Add a custom "Short Description" column.
 *
 * @param     array     Unfiltered columns for the taxonomy's edit screen.
 * @return    array     Modified columns for the taxonomy's edit screen.
 *
 * @since     2010-05-31
 * @alter     2011-01-09
 */
function mfields_taxonomy_description_columns( $c ) {
	unset( $c['description'] );
	$c['short_description'] = 'Description';
	return $c;
}

/**
 * Display the shortened description in each row's custom column.
 *
 * @param     string    Should be empty.
 * @return    string    Name of the column.
 * @return    string    Term id. Integer represented as string.
 *
 * @since     2010-05-31
 * @alter     2011-01-09
 */
function mfields_taxonomy_description_rows( $string, $column_name, $term ) {
	$description = '';
	if ( 'short_description' == $column_name ) {
		global $taxonomy;
		$description = term_description( $term, $taxonomy );
	}
	return $string . mfields_shorten( $description, 40 );
}

/**
 * Shorten a string to a given length.
 *
 * @param     string    The string to shorten.
 * @return    int       Number of characters allowed in $string. Defaults value is 23.
 * @return    string    Text to append to the shortened string.
 *
 * @since     2010-05-31
 * @alter     2011-01-09
 */
function mfields_shorten( $string, $length = 23, $append = '...' ) {
	$string = strip_tags( $string );
	$string = trim( $string );
	$string = html_entity_decode( $string, ENT_QUOTES, 'UTF-8' );
	$string = rtrim( $string, '-' );
	return ( strlen( $string ) > absint( $length ) ) ? substr_replace( $string, $append, absint( $length ) ) : $string;
}

Hope someone finds this useful.

Mad Props to the Following…

The following solution was created gluing together two tutorials that I have read. The first is an easy to follow article by Jeff Star on Perisable Press titled How to Import and Display RSS Feeds in WordPress. Jeff walks us through using the SimplePie class. The second tutorial was written by Devin Price and focuses on controlling what is displayed on the WordPress Dashboard and is titled Dashboard Support Widgets.

My goal was to combine these two tutorials into a custom solution where I would create a custom Dashboard Widget that displayed the 10 latest support questions for all of my plugins hosted on WordPress.org.

Create a Cache Directory

The first step is to create a cache directory on the server where WordPress is installed. In this example, I have created a directory named “wordpress-plugin-support-cache” directly under /wp-content/. You will want to set the new directory’s file permissions to 755.

Getting the Feeds

Fortunately, the Plugin Directory provides us with a public RSS feed for each plugin’s support section. The first step in finding the feed is to navigate to the plugins main page in the directory and click on the “Forum Posts” link.

You will want to click on the little orange RSS Feed icon to the right of “Forum Posts”. This will take you directly to the feed. Clicking on the text “Forum Posts” will bring you to a tag archive for support forums.

Save Some Time!

You do not need to follow the above process every single plugin that you have. Once you have one feed all you really need to do is modify the unique identifier in the url. Here’s the url for the support feed for my Taxonomy Images Plugin:

http://wordpress.org/support/rss/tags/taxonomy-images

The unique identifier here is “taxonomy-images” which is basically the title of the plugin in lowercase with spaces replaced by dashes. Here are all the links to my plugins hosted on Wordress.org:

http://wordpress.org/support/rss/tags/category-radio-buttons

http://wordpress.org/support/rss/tags/taxonomy-widget

http://wordpress.org/support/rss/tags/taxonomy-list-shortcode

http://wordpress.org/support/rss/tags/taxonomy-images

http://wordpress.org/support/rss/tags/taxonomy-terms-list

http://wordpress.org/support/rss/tags/bulk-image-resize-utility

Creating the Widget

if( !function_exists( 'mfields_dashboard_widget_plugin_support_aggregator' ) ) {
	function mfields_dashboard_widget_plugin_support_aggregator() {
		$feed_urls = array(
			'http://wordpress.org/support/rss/tags/category-radio-buttons',
			'http://wordpress.org/support/rss/tags/taxonomy-widget',
			'http://wordpress.org/support/rss/tags/taxonomy-list-shortcode',
			'http://wordpress.org/support/rss/tags/taxonomy-images',
			'http://wordpress.org/support/rss/tags/taxonomy-terms-list',
			'http://wordpress.org/support/rss/tags/bulk-image-resize-utility',
			);

		include_once ABSPATH . WPINC . '/class-simplepie.php';
		$feed = new SimplePie();
		$feed->set_feed_url( $feed_urls );
		$feed->set_cache_location( WP_CONTENT_DIR . '/wordpress-plugin-support-cache/' );
		$feed->set_cache_duration( 999 );
		$feed->handle_content_type();
		$check = $feed->init();

		if ( $check ) {
			print "\n\t" . '<ul>';
			foreach ( $feed->get_items( 0, 10 ) as $item ) {
				$blog = '';
				$href = $item->get_permalink();
				$title = $item->get_title();

				print "\n\t" . '<li><a href="' . $href . '">' . $title . '</a></li>';
			}
			print "\n\t" . '</ul>';
		}
		else {
			print "\n\t" . '<h2>Feeds currently not available</h2>';
			print "\n\t" . '<p>Please try again later</p>';
		}
	}
}

This function is based of the knowledge that I gained from the SimplePie article on Perisable Press. You will want to replace my feed urls with you own in the $feed_urls array.

Register the Dashboard Widget

if( !function_exists( 'mfields_dashboard_widget_plugin_support_aggregator_init' ) ) {
	add_action('wp_dashboard_setup', 'mfields_dashboard_widget_plugin_support_aggregator_init');
	function mfields_dashboard_widget_plugin_support_aggregator_init() {
		wp_add_dashboard_widget(
			'mfields_dashboard_widget_plugin_support_aggregator',
			'WordPress Plugin Support',
			'mfields_dashboard_widget_plugin_support_aggregator'
			);
	}
}

This function was derived from the code that I found in Devin’s article. If you would like to change the title on the widget please modify the second argument passed to the wp_add_dashboard_widget() function.

That’s Really All There is to It!

You can copy and paste the following two functions into you theme’s functions.php or use them in a custom plugin.