There is no denying that feature-wise Wordpress offers everything that an amateur or even a professional blogger could need.

Unfortunately, something I always suspected of WP but never wanted to admit was internally there was a level of chaos which might spill out and hurt me.

Well last night, hurt me it did. I am not sure whether an edit to the theme, a new plugin or a recent upgrade was responsible but I noticed the feed was no longer validating and various applications were having trouble with this including Feedburner.

Feedburner’s FeedMedic led me quickly to discover an errant white space at the start of the file.

Familiar with PHP as I am I thought that following the execution logic from the index page (to which passing a parameter would yield the feed to be returned) should eventually locate the mischievous white space.

The first few files seemed straight-forward and single purpose however the more I dug, the more apparent WP’s internal discord became. Globals, functions everywhere (including a whole stack in a file called ‘functions’), procedural code and the occasional class that of course gets instantiated into the global namespace.

After about an hour of checking through the end of php files trimming white space and double-checking every echo I could locate I decided to take another tack. I tried to create a simple file which just recreated the variables I needed for the feed file to work.

This work revealed a very deep hierarchy of requires - as I added in one require it would require further dependencies which as I proceeded seemed less and less relevant to the work required to render the feed.

Finally I realized that WP was not going to let me debug this issue in any sort of reasonable time (without setting up a step debugger or retracing my steps earlier with echoes until I located my space) and I should just accept that a space was being buffered and I should try clear it just before I echoed my feed.

Some quick research on php.net and the only function which looked like it might clear the default output buffering php uses was ob_clean. I’d always thought this would only apply to output buffers I’d explicitly setup but it seemed to do the trick for my feed.

So what to conclude from all this?

I believe blog software will continue to evolve - but I wonder whether Wordpress be able to keep pace with all its technical debt?

That a space can break an application is somewhat of a flaw in PHP. (Using a template system with PHP helps avoid that regular case of unwanted output creeping in after a close tag.)

That it took a few hours to get a resolution on this issue is a critical flaw with Wordpress. Whilst this doesn’t seem to have hindered what appears to be the healthiest plugin support of any blogging platform I feel it will ultimately limit the competitiveness of Wordpress as better architected solutions which can foster a dedicated plugin development community similar to Wordpress come to the scene.

Stumble it!