Javascript is a slippery beast, Slave to no one and master to many. It’s just a quick blog post today, not as quick as this article I found written by me
CRM 2011 – Javascript snippet – How to remove all existing values from an OptionSet
I’m more happy in the .net and C# world with it’s static variables.
What I mean by this is C# you have to declare the variable you are going to use e.g.
- string
- int
- bool
- custom type
but with Javascript a var can be anything, it’s like something out of X-men changing and morphing it’s way along.
Here is a good article about static and dynamic languages
Static vs. dynamic typing of programming languages
Why doesn’t Hosk like Dynamic Javascript
Good question, surely I should like dynamic things.
Some of the reasons I don’t like it are
- Hard to read/understand other peoples code
- Bugs can be compiled and then appear in runtime when the code is run
- It encourages the cowboy coders to go to town
- It’s strange and different
Get to the point
I’m not saying I don’t like Javascript it’s just sometimes I want to do things and I’m not sure HOW because the syntax can be a bit crazy. Like all developers once we have a working example in our hands, we are off. So recently I saw some interesting Javascript in a project I am working and I was intrigued to understand how it worked and use it again.
One cool feature about Javascript is the ability to pass in function names using variables, a bit like reflection(ish), but only once you know how because I tried searching for this on the internet and fell down a big dark hole.
Example
On a form I have 4 OptionSets which we are dynamically setting the values to.
If I pass in the OptionSetField name I can dynamically get the control
var control = Xrm .Page .getControl (OptionSetFieldName);
I can then clear this control
control. clearOptions();
I can then add in the new values and build it up. The beauty of dynamic code is I can use the same code for all the OptionSets because I can pass in the name of the control.
When adding a the new optionSet values in, I can use a dynamic variable to retrieve the field name from array, which contains values retrieved from a fetchXML query. The childField is the name of the field in CRM.
var option = {
value: retrievedOptionSet[i]. text == "" ? "null" : retrievedOptionSet[0].attributes [childField]. value,
text: retrievedOptionSet[0].attributes [childField]. formattedValue
};
control. addOption(option);
}
Summary
It may be common knowledge to all you JavaScript wizards out there, but I hadn’t used or seen JavaScript using dynamic names. It makes sense and it’s very useful so I thought I would share it with you
Hosk's Dynamic Blog 
This looks like a pretty interesting technique – thanks for introducing me to this as a new idea. I was not aware of this. Not sure how often I would use it, but one to have “in the toolbox”.
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Ben, have you investigated simpleXrm.js?
I built it specifically to address many of these frustrations. It is naturally still bound by the limitations of the language and Microsoft’s APIs, but CRM JavaScript is given a heaping helping of syntactic sugar, encapsulation, and normalization.
It allows you to more easily read your code and your colleagues ‘, and also collapses the complex API plumbing into a library layer that can be updated on a per-organization basis to handle breaking changes in Microsoft’s APIs.
Documentation is my biggest hole right now. The feature set is rich but like most FOSS it’s a time consuming hobby, and I have only so many hours in the day.
Anyway I think you might appreciate the effort since you obviously have encountered many of the same pain points with JavaScript in CRM that I have.
Cheers!
Joe
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