The Correct Way To Add Plugin’s Functions Into Themes

I recently deactivated a plugin on this blog only to find that the blog stopped working. On the home page, only an error was displayed. The error told me that I was trying to call some function that didn’t exist. Clearly, the function disappeared because of the deactivation of plugin. To check my theory, I re-activated the plugin and the blog started working again.

The plugin I deactivated was related post plugin, and when I checked the theme files, there was a call to the function,

I removed that function call and deactivated the plugin, which fixed the issue.

I am sure that you must have came across the same same issue in the past. Here’s a solution to the issue-

The Correct Way To Add Plugin’s Functions Into Themes

The correct way to call plugin’s function in a theme is this,

As you can see in the code snippet above, an if condition is used to check if a function exists. If it doesn’t, then the won’t be called, thus preventing the blog from breaking completely.

So, to call related_posts function, the following code should be added to the theme theme’s template files,

Now, even if the related posts plugin is deactivated, it won’t affect the blog.

If you are a WordPress theme developer and you want to integrate a plugin with a theme, or if you are a WordPress user who need to add a function call to theme files to use some plugin, then please add the function call in the correct way.