One of the most important things you need to know when writing JavaScript files in Drupal is the concept of behaviors. But in order to understand that, let's get a bit of context.
When writing JavaScript code using jQuery, it's often standard to wrap our code inside a ready() method statement as follows:
$(document).ready(function () {
// Essentially the entirety of your javscript code.
});
This ensures that your code runs only after the entire DOM has been loaded by the browser. Moreover, the use of jQuery for this helps a great deal with cross-browser compatibility and also allows us to place this code wherever we want on the page (header or footer).
In Drupal, however, we have a different solution which is better in the ...
