Calculate Totals of certain list items and display via custom view as a webpart for [me] users

Question

I'd appreciate your advise on this.

I've seen Java scripts for this, but I'm not sure if I need this. I hope not and I hope I can do something like this in a workflow.

I have a list for staff to request a holiday. Say they have 250 hours per year. When they add a new list item and say request 10 hours holiday, then I'd like the Balance info to be showing on their Home page. They don't need to see the list of holiday requests, just their own requests on their own webpart.

There's one list for all different staff. I just want to calculate totals for one particular person and display it via custom view per [me] if that makes sense :P

Something like this:

Column 1 is Hours Taken, Column 2 is Remaining, Column 3 is Allowance

Item1 Person1 10 240 250
Item2 Person2 25 225 250
Item3 Person3 50 200 250
Item4 Person2 10 215 250
Item5 Person1 15 225 250
Item6 Person2 50 150 250

So when Person1 is logged on, this person should only see column 2 which is 225, Person2 150 and Person3 200 hours left.

Is this doable using SPD 2013 on Sharepoint Online workflows?

Unless I can use excel files to do the calculations and have them update sharepoint lists automatically say once a day?

I'd be grateful if you could put some light on this ;)

Answer 1

If you go with Workflows and List views it will become really complicated.

There is no harm in using SharePoint JavaScript API's. Just add a script editor webpart and query the list using CAML + JSOM.

Loop the requests and add up total applied. Then subtract it from total allowed per year.