Some more thoughts about trampling over $
I am on a spree today. The number of topics I wanted to blog about has accumulated, and I just decided to dump the stuff over here while I both…
Preventing trampling over $
In my previous post, I’ve written about the situation when you (or somebody you trust) redeclares the $ variable, thus inadvertently breaking all your jQuery code. I’ve also explained how to remedy for it inside the code you write by applying the Immediately Invoked Function Expression (IIFE) or Self-Executing Anonymous Function pattern.
However, is there anything you can do to prevent anyone from trampling over $ or jQuery variables in the first place?
As I said in my last post, yes, and no.
Let’s take a closer look at it.
Why doesn’t my jQuery work?
First, a disclaimer. This post is written for (C/)AL developers who are struggling with JavaScript, who copy and paste JavaScript code from Stack Overflow right into VS Code and are happy when it works, and confused when it doesn’t. Still, if you are not a (C/)AL developer but want to learn a bit of JavaScript yourself, this post is not at al about AL, it’s purely about JavaScript, and about demystifying a piece of it that JavaScript developers take for granted, and that developers with experience only with simpler languages (such as AL) find confusing.
Now let’s jump into the point. A friend asked me for help with a control add-in in which “jQuery doesn’t work, I can do jQuery() but I cannot do $()”
This is one of the schoolbook examples of what happens when you don’t isolate scope in JavaScript, so let’s first see what happened, and then let’s see how you can fix it.
Abusing Images property to load HTML in control add-ins
One of major limitations of control add-ins is not being able to define HTML. It seems so unbelievably unbelievable, that anyone looking at it from the outside of the NAV/BC playground may say “obviously, you must be missing something!”. But I am not. The one thing that you would expect to find first when defining a control add-in (and control add-ins in NAV/BC are nothing more than pieces of HTML that live within the allocated area of your browser real estate) is to be able to define the HTML. And yet, you can’t define it. The only way to show any UI from your control add-in is to procedurally create any of your control add-in HTML.
This makes no sense. No. Sense.