Reply To: Fatal error in query.php line 28

04/08/2016 at 10:29 am #372136
Steven Zahm
Keymaster

@ Kathy

This is actually not a bug in Connections, more likely a bug in the theme which is incorrectly using and therefor breaking the global WordPress variable $wp_query. You can read the nitty gritty details in this FAQ.

I run into this issue 5–6 times a year. Mostly in older theme’s which have not been updated in quite awhile. On odd occasion I see it in a newer theme. Likely because the theme dev copied the code from an old tutorial. Of course, the later, is just a guess.

I’m also been running into a new variation of this. A plugin or theme, maybe even the actual users are editing a core WordPress file query.php by commenting out code which will break a lot of plugins, silently. More about it in this post.

All this said…

I use a core WordPress function named get_quer_var() extensively throughout Connections. Which is the proper best practice in order to retrieve a public query variable registered with the core WordPress WP_Query class.

Since this is a core WordPress function and I am quite correctly using get_query_var() to retrieve it. This function should “just work”. However, those two issues mentioned above being caused by third party themes and plugins causes Connections to break about a dozen reported times a year. It important to note that this does not only affect Connections, but every other plugin which correctly uses the get_query_var() function.

I’ve come up with a work around which will be included in the next release of Connections. This work around involves creating a wrapper function for get_query_var(). I updated well over 300 instances of get_query_var() function used in Connections to use this new wrapper function.

What does this wrapper function do? It checks that get_query_var() is callable and that the $wp_query variable is not “broken”. If both are ok get_query_var() is used like normal. If either are “broken” I go thru several other checks and in each check try to call the query variable a different way.

In short, this should work around the issue being caused by third party plugins and theme.

Now, this will not fix other plugins being broken silently by the same issue. So if you run into other odd quirks or something else not working with other plugins it could very well be the very same issue that affected Connections.

I know this is a long technical reply but I hope it helps!