Load only select sections of Code in QlikView - qlikview

Question

I have a set of code that is rather large in Qlik. I have dates that are defined at the start of the script
i.e.
Let vBDate = Date(Date#('01/01/2015','MM/DD/YYYY'),'MM/DD/YYYY');
Let vEDate = Date(Date#('12/31/2015','MM/DD/YYYY'),'MM/DD/YYYY');
The entire code runs financial numbers based on a specific data source. Originally I had a version of this QVW for each data source. However, as often goes with financials the QVW constantly needs to be refined. So I merged them all into one code. I broke the Code up into different tabs so I can turn off the sources I don't want.
What I want to do is try to se a variable, either in the code, like this,
Let vROIType = 'Vendor';
or using the method answered in my first attempt at this question where the variable is defined on the designer side using a button.
The hope is that when the variable is set, then only the code associated with that variable will run in the reload and the other code will be skipped.
In my research I tried to create functions in the script and use code to call them, however the call would always error out. I also read about QVDs but many of my date variables are defined at the start of running it, and the QVD needs to be pre-run.
Any help would be appreciated.

Answer 1

As long as you wrap the appropriate sections of the script in the conditionals properly, this should accomplish it:
Create a variable via the Variable Overview window (ctrl + alt + v) like you mentioned to reference the correct script to be reloaded (vROIType)
Create a button or text box and set an action to change the value of the vROIType variable. You can just make two buttons so you can select the correct data source by clicking the appropriate button.
Either reload via the menu or create another text box/button with an action to reload your script.
Most importantly, use conditionals in your script to selectively run the correct portions based on the vROIType variable.
if vROIType = 'Vendor' then
Everything in the script you want run when the source is `Vendor`.
elseif vROIType = 'SomeOtherVendor' then
Everything in the script you want run when the source is ....
end if;
Upon reload, the script will look at the vROIType variable and use that to determine whether or not to run parts of the script. Here's a link to a simple example you can try if you have the paid version of Qlikview, otherwise it'll yell at you that you can't open third party .qvw's.