Thanks to Mark Rackley and Scott Brickley, who have contributed much help and information toward the following solution I've been working on.
At this point, everything seems to work except my attempt to redirect to a new URL after a new item has been saved. Scott Brickley gave me the foundation for the 'changeNewItemRedirect()' function, but I haven't got the syntax correct somewhere and it fails to redirect. I'm not sure at this point, if the problem is with my lack of understanding of '_spPageContextInfo.siteAbsoluteUrl' and perhaps there is an issue with my concatenation after that? I'm attempting to have it land back on the Display form of a parent list.
The functionality of grabbing the ID of the Parent item is there and working for my other function, so I would assume it would work in this one as well. However, perhaps I'm going to have to add some parenthesis or alter my quotations somehow, to get the syntax right?
Thanks for taking a look and for any suggestions you may have.
Everything in this code seems to be properly formatted and appears to be working...the redirect just doesn't happen.
I dug deeper into the Dev Tools in my browsers and was able to find the ability to 'Watch Expressions' in Chrome. I was able to add a watch for WPQ2FormCtx.RedirectInfo.redirectUrl. When the page loads, nothing shows up as the value for this, however by refreshing the 'watch', the url value I'm pushing comes up in perfect form, properly displaying the value from the concatenated query string value. I can copy the URL there into a browser window and it immediately pulls up the page I'm shooting for.
However on clicking 'Save' from the new item form, when it should redirect to my injected value, it instead goes straight back to the main parent list view, which is the default behavior. It never redirects to the intended page. I'm stumped. It seems like everything is correct, but the functionality doesn't happen. Could it be a timing thing with _spBodyOnLoadFunctionNames? Any suggestions? Thanks for your insight.