Control Add-in

In the last example I put online, we’ve noticed that it was difficult to achieve a good separation of concerns in the front end if we are building UI directly through DOM . Apart from the fact that it’s very inefficient, manipulating DOM directly makes it very difficult to structure your front-end logic.

Now that you are done through this mouthful of the title, you may recognize that it’s the method you invoke when you want to run a control add-in trigger in AL from JavaScript. There is nothing new about this method itself, it’s just that most people aren’t aware of full power of this method, and they are using this method in a very inefficient way.

This post has been long overdue. I’ve had it in my to-do list for nearly four years now, but it always ended up in the not today category. Funny how many times I’ve implemented it already, and how many times I’ve presented this, and I never ever found a few minutes to create a demo repository and a blog to come with it.

Happy new year everyone! Last year was a bit slow for me, until the very end, when I churned out a year’s worth of posts just in two days. I hope this year to be a bit different, and let me kick-start it with a concept I’ve been playing with recently.

The last of the NAV TechDays 2018 demo series comes with a little story. While Waldo and I were preparing the “Evolution of the Titan” session, on Sunday before the conference, we were brainstorming the ideas of what would constitute a cool non-visual JavaScript demo.

One of the more effective, and probably completely unexpected, demos at Waldo’s and mine NAV TechDays 2018 session was the user profile picture demo. I say “completely unexpected” is that it shows something that you normally don’t expect from control add-ins.

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?

I usually post my NAV TechDays demo stuff for you to use and abuse, and this year won’t be an exception. There are three changes, to previous years, specially the last year. First, you won’t need to wait until New Year’s Eve for me to post my stuff. Second, I’ll blog each of the demos individually, because of the third reason.

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.

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.