For a longgg time now jelly is something that has scared me. I'm just starting to get over the fear because I have learned why it's scary!
You're a developer, and you like to learn by example. So you dig into some UI Macros or UI Pages and your first thought is, what the?!
No let's think of jelly having a complexity scale of 1-10; 1 is easy and 10 is hard. Most of what you will see that has been implemented falls somewhere in the complexity range of 7-10. Let's compare this to something with which you may be more familiar.
Ok, you've never worked with javascript but are eager to learn. The first thing you do is try to work with JS objects or maybe functions. You will fail and never want to try again.
Here's how I think of jelly (I'll admit I'm not an expert):
An envelope containing information. In this envelope is javascript and HTML. In actuality this envelope is XML that is turned into code.
The hardest thing for me to understand was the 2 phases:
The
<j>
and
<j2>
namespaces are standard Apache jelly.
The
<g>
and
<g2>
namespaces are specific to Service-Now referring to glide.
The way the XML is rendered is:
<j>
and
<g>
namespaces are processed and cached. Then
<j2>
and
<g2>
are processed and not cached.
However, to get over you're fear of jelly... Create a new UI Page. Use the technologies you are familiar with. Gradually work on using some jelly tags. Then go back and look at the OOB stuff. I'm sure it won't look as intimidating!
