What exactly does wp_enqueue_script do?

Hi Brittany Cerra,

So, here's how the process works and I'll use stylesheets as an example There's 4 functions involved in getting a stylesheet linked up and working.

Deep in the core of WP is a function that's got a name of wp_enqueue_scripts. What this function does is add the markup the same as we would for putting something in the head tags with the necessary markup to include a style sheet.

So that's our function that's actually going to create the markup so we can have a stylesheet. We don't need to worry too much about it other than know we need it.

Next up, we need to actually link our stylesheet to our programme, the website. For that, we need to write a function that will take where we're storing our stylesheet and tell the function in the core where it is. Now the core function knows what stylesheet we're talking about and where it is. This is our wp_enqueue_style function. We tell this function what we want to label the stylesheet as, that it's in our theme directory and where in our theme directory it is.

Now we put that code in our own function so we've got something to pass to our 4th function which is the add_action() function. We need to put it in a function because, as we know, functions are isolated blocks of code that operate on their own but only when we ask them to. Functions require arguments to be passed to them, ie other functions.

We can call our function wrapping wp_enqueue_styles whatever we want but for the sake of maintainability, we call them sensible names. Same sort of logic with variables, classes and the like.

So we've got 3 functions we're dealing with at the moment.

Last thing we need to do is get it to run. Again, looking back at the wp_enqueue_scripts function, that will have a stipulation that determines at what point in the programme it runs. In our instance, when wp_head() fires, it will fire along with many other functions. May not be wp_head() that fires the function, I'd need to check.

Either way, what we do is add an action. An action is simply a function that runs other functions. We pass it two arguments, WHEN to run WHAT function. So, our add_action reads like this:

add_action('run_it_during_the_creation_of_the_document_head', 'something_to_link_our_stylesheet');

I think that basically covers it. I'd like it for Zac Gordon to validate my explanation just to be sure I'm not talking mumbo jumbo. :)