I tried to understand the coding in app.js in order to understand how some of the function works.
all the functions are with a and b parameters
can someone assist?
The code is ofuscated - Is not the same as encrypted.
It's a simple protection but the code will more difficult to read depending of level of ofuscation used...
Use google chrome Developer Tools to debug it...
Internal functions and variables are replaced with shorter names as the JavaScript is minified. All applications should be minifed. If you are used to seeing application code that is not minified and ofuscated in this way, then you are either running on development builds or there is some reason why the code isn't minified, like a knowledge issue or lazyness :-) or it's just so little code that the overhead of minifiying it is not worth the effort of setting that up.
I would start by searching for the public facing method name (as it will keep it's name if it is called from the HTML for example, or if there is an event that is subscribe to, then I can search for that name. But basically I would start to look at the HTML for the event that triggers something or if there is something that you can search for in the URL that would not be minified.
But if you have find what you think is the method then you use the Browser developer tools and add a break point to inspect the values of a and b and with that you might be able to guess what it is.
This is all a bit tricky when you don't know the code or when you are not used to minified JavaScript because it can look quite different. But there is just no way to know what stuff are to reveres engineer it back to real variables names etc.
I don't have access to EAM so I would not know and also you need to be very specific and share the exact code snipplet for someone else to be able to search for it and perhaps find it and give you a tip. a and b will be used all owver the place.
But I really like your curiosity
https://developer.chrome.com/docs/devtools/javascript/
The real "Reverse Engineer" is not applied to JS because the code is never compiled.
The Functional aspects: variable a is xxxx, variable b is yyyy must be found by developer....
Infor don't ofuscate the code (JS, java, ...) as You said - only compress it (minified) so is not a very hard job to know what
each variable really is - is just a question of time.
As pointed by others the EAM.* classes are in minified form.To quickly navigate and understand the EAM classes I've resorted to parse the pretty-printed version of app.js(saved from Chrome - F12 - sources -app.js - pretty print - save [AFTER loging into EAM])parse it with javascript syntactical parser and saving all classes in a tree hierarchy on disk.(even if the 12 MB app.js file it's easy to search and understand).
Just a trick for Sencha Ext js classes embedded on app.js : you can see the sources at, e.g. https://docs.sencha.com/extjs/6.5.2/classic/Ext.toolbar.Toolbar.htmland then clicking the "source" gray label : it's in expanded form with interesting comments.
good luck !
Davide Grandi