Updating SharePoint Lists with the JavaScript API

A while back I ran into an issue while trying to use SharePoint to store information that had a certain type of relationship between the lists. I wanted to be able to have a user enter a record, but then use a lookup column to select one or multiple items from another list. Based on the selected items, a value would be calculated using other columns from the chosen items. Basically, the situation got a bit out of the box for what was available using the web browser, calculated columns or SharePoint Designer.

I did a bit of research and found that I could do my "more complicated" math calculations outside of SharePoint (yay) and then just dump my cleaned up data back into SharePoint once I was done. And it actually was not that messy, I just had to get familiar with the JavaScript API.

I did this last year, but just dusted off my personal documentation and figured maybe it would come in handy for either myself or someone else in the future. In case you might want to use something similar, check out the blog post I just whipped up and let me know if it comes in handy for you. Or, if you can think of a better way to accomplish something similar, let me know also :-)

The post I put up is on my wordpress blog, at: https://gregbesso.wordpress.com/sharepoint/javascript-api-readwrite/