Sniffer what?

Like a network packet analyser (or sniffer), the WordPress Hook Sniffer intercepts and logs a stream of data. In this case the data is the hook events from the Plugin API that WordPress runs on a request. The plugin outputs the stream of events and the sequence they are fired to either a text file or the screen.

WordPress allows plugin developers to ‘hook’ custom functions onto the core events. Hooks can be in the form of Actions and Filters.

What is an Action?

An Action is a specific point in the WordPress core sequence of loading events. A plugin can hook multiple functions to multiple actions.

For example, your plugin needs to add a link to its settings page under the ‘Settings’ menu. You would create a function to add an options page:

public static function add_settings_menu() { 

     add_options_page( 'Instagrate to WordPress',
                       'Instagrate to WordPress',
                        1,
                       'instagrate-to-wordpress,
                       'settings_page');

}

You would then ‘hook’ the function ‘add_settings_menu’ onto the admin_menu action:

add_action('admin_menu', 'add_settings_menu');

Check the WordPress add_options_page→

What is a Filter?

A Filter is a way of changing certain text that WordPress uses before it is served up to screen or written to the database. This is very helpful for plugin and theme developers.

A classic example is the changing the length of the excerpt of a post. You would create a function to return a custom excerpt length:

function pvw_excerpt_length($length) {

       return 35; 

}

You would then ‘hook’ the function ‘pvw_excerpt_length’ onto the excerpt_length filter:

add_filter('excerpt_length', 'pvw_excerpt_length');

Configuring the plugin

The plugin is very simple to set up. First radio button group allows you to enable or disable the logging. The next part allows you to configure the output options:

There is a detailed description of each option here, but you really want to be selecting all to get a clear picture of what is going on. And lastly set the output location of the sniffing. Output to file for easier analysis in a text editor.

The Analysis

The output is comprehensive. The first section lists all the added action and filter hooks. It’s always best to check your function is being hooked into the correct function:

317: add_action( 'wp_loaded', 'instagrate_to_wordpress::auto_post_images' ) Called from: /.../wp-content/plugins/instagrate-to-wordpress/instagrate-to-wordpress.php | line #: 60 --> Time Added: 1331855684.0738

Then check out the ‘Action and Filter Function Array’ section. This lists the array of hooks and the functions hooked into them, in order. The real crux of the analysis is the section which lists the ‘Action Event Firing Sequence’. This has a timestamped list of all the actions that are fired. This is very helpful in working out what’s happening where, when and why. For example, an early version of the plugin had it’s main function hooked into the loop_start so it only added new posts when the blog page was requested. However, this was poor approach and resulted in the function being called multiple times on page when widgets were in play that also used the loop.

After playing around with the init and wp_loaded hooks, but realised that the function was getting called on every page load, admin, post, category, everything. That’s when after trawling the WordPress API reference I came across the template_redirect hook. This is the earliest hook point during the page load that can interrogate the WordPress core to work out what type of page is being served. You can use the function is_home() to check if it’s the blog page that is being loaded and action your script accordingly.

The bug fix is still on going, but discovering this plugin has added another level of visibility into the inner workings of the WordPress core and is a must for any plugin or theme developer.

Further reading

WordPress Plugin API→
WordPress Plugin API Reference→
Introducing WordPress Hook Sniffer: a Developer Plugin→
WordPress Hooks, Barbs, and Snags→

Reading some of the previous reviews and checking out the app’s site www.koderapp.com it looked like it did exactly what I was looking for. Local, Dropbox and FTP integration and synchronisation. Inbuilt browser and syntax highlighting in what looked like a powerful text editor for the iPad. Some negative reviews about crashing and issues with the previewing slightly put me off, however a newer version 1.2.2 had since been released which apparently addressed these issues.

So I took the plunge and downloaded it. For just £3.99 or $5.99 in America, this is a steal for the features and functionality you get. On first load I was impressed with the UI and ability to theme and style the editor’s look. The file browser sidebar is collapsible so you can edit the files in full screen mode. As I am a Coda user on the Mac it was nice to see a similar snippets area for frequently used code ‘clips’.

After playing around with some files on my FTP server I went to preview the files. I was pleasantly surprised to see Firebug as an option in the browser (I hadn’t read the features fully!) it’s great to be able to debug files on the fly like this. I’m not sure how well the touch screen works with Firebug, as you could end up clicking on the wrong thing again and again.

On the whole this is a featured packed app that is a great iPad solution to website changes on the fly. Of course this will not replace Coda on my MBP but that is not why I have downloaded it. If you want a strong iPad app for text editing and website changes then go get it for a small £3.99.

Like any product released to the public it has had its bugs and issues. I think I underestimated its uptake and therefore was slightly unprepared for the amount of feedback and contact I had. In order to support the plugin better I have set up a support forum for primarily the Instagrate plugin, but later for other plugins that are released.

The forum is built using the bbPress plugin from the creators of WordPress. It also has been extended by the plugins bbPress WP Tweaks for sidebar goodness and bbPress New Topic Notifications for email notifications.

I look forward to developing the plugin further in response to many great feature requests. I also intend to develop and release other plugins, so keep an eye out.

Twitter has it. Facebook has it. Flickr has it. Tumblr has it. Posterous has it. Foursquare has it. Now WordPress can have Instagram integration too! This plugin brings together the wonderful image sharing tool Instagram and your WordPress blog.

No more manual embedding Instagram images into your posts, let this plugin take care of it all. Install the plugin. Log in to Instagram, pick your default WordPress post settings, and you are done. Take a photo or lots on Instagram. The next time someone visits your site, a new post will be created with your each photo from Instagram.

Check out the plugin page for more details here and on the WordPress plugin directory.

Download Plugin Plugin on WordPress

I signed up back when it first came out but have only really been using it in the last six months. It is amazing. Simple and effective and most of all free. 2GB when you sign up. The paid plans seem reasonable, but for what I use it for at the moment, unnecessary. I make use of their awesome referral scheme which gives both people 250mb free extra on signup and install. Here is my referer link http://db.tt/Y1ovFX6 (of course).

Go, sign up, change files, sync and enjoy.

Dribbble is a show and tell site for designers and illustrators to share their work and (hopefully) receive constructive criticism and/or praise.

I have recently received an invite to draft someone to the community and thought I would partake in the now cliched process of giving the invite away on the basis of portfolio submissions.

So if you want to be in with a chance to get drafted make sure you are a prospect on the site, comment on this post with your Dribbble username and a link to your portfolio. Depending on the uptake, I will review the submissions in a couple of weeks and then dish out the draft to someone.

Simple as that.

And go!

For sentimental sake here is the previous version of polevaultweb.com

As I write this post I am satisfied with the design and happy with the execution. I only hope it stays that way.