Control Add-ins – Page 5

Extending the HTML trick: using actual images

Post published:December 12, 2018
Post comments:3 Comments
Reading time:4 mins read

Eric Sevareid famously said that the chief cause of problems is solutions. The same applies to the HTML trick I blogged about yesterday. As soon as you solve the problem of using HTML directly in your control add-ins, another problem arises: what do you do with actual images your control add-in includes?

This post explains how to solve that problem, and how to make it possible for your control add-in to both use HTML for defining UI and use relative control add-in paths to images.

Let’s dig in.

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Encapsulation in JavaScript

Post published:December 11, 2018
Post comments:4 Comments
Reading time:6 mins read

This will be my last post in the “JavaScript for (C/)AL Developers” series today. If I continued blogging about nearly pure JavaScript stuff, you could reasonably ask if this is in fact an NAV blog or a JavaScript one. It’s still NAV, and while the stuff I am about to write about is purely a JavaScript concept, I find it highly relevant for any control add-in developer. So, hold my beer, and bear with me for another one.

One of the complaints I often hear about JavaScript is that in JavaScript there is no encapsulation. This is almost completely true, except for the fact that it’s entirely false.

Where is the problem in the first place, and then what is the solution? Let’s dive in.

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Preventing trampling over $

Post published:December 11, 2018
Post comments:8 Comments
Reading time:9 mins read

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.

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Why doesn’t my jQuery work?

Post published:December 11, 2018
Post comments:9 Comments
Reading time:8 mins read

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.

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Abusing Images property to load HTML in control add-ins

Post published:December 11, 2018
Post comments:18 Comments
Reading time:9 mins read

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.

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