Delegation problem using SharePoint online data source

[jefferson]

I have read endless articles about what is supported for delegation and I cannot find an answer to my problem.

I have a SharePoint list with a lookup column linking to a library (I have also tested with a list). In my app, I want to filter the items in the lookup based upon a different (Supplier) column in the lookup list. That column is a simple text field too.

I have created a data source to the lookup library ('New Goods - FE Product Catalogue') which contains just over 1000 items. I have amended my combo box ITEMS property to use my new data source and immeditaely the blue cirecle appears. It doesn't matter whether I apply a filter or not, still it does not delegate.

So the be clear, it does not matter if my combo ITEMS property is:

'New Goods - FE Product Catalogue'

or with a simple Filter:

Filter('New Goods - FE Product Catalogue', p0f5=CmbSupplierValue.Selected.Value)

In both cases I get the delegation error. So I guess my question is do SharePoint Online connections support delegation, am I doing something wrong or is there a workaround to this? Any help would be much appreciated.

[Shanescows]

Hi @jefferson

Let me first start off with the note that PowerApps and LookUp columns are not best friends. I avoid them like the plague for that very reason. 🙂 

The problem is your Combo Box is trying to query the Lookup column and that causes you to get the delegation warning. If you use a different column you will not get the delegation warning anymore. I just recreated all of this in my test environment. SharePoint Online isn't the issue, it is LookUp Columns. I believe the problem is the Combo Box uses the Search function under the hood and it doesn't support the LookUp column. 😞

You may have to look at the problem from a different angle. 

[jefferson]

Thanks so much for coming back to me. I was starting to become suspicious about the lookup (just by elinination there was little else left), though it is counter-intuitive because I am overiding the ITEMS property and the field I am looking up to is just a text field.

If you are right, is it reasonable to assume I could add a separate combo box control (outside the SharePoint form) that I apply my lookup datasource to? So in no way connected to my lookup column? Because if I do that, I still get the blue circle as soon as I apply my datasource.

Interestingly, if I add a gallery control and use my data source, it does not show a blue circle. Is this a false-positive on the combo box do you think? I have tested both the original SP combo box and my new control return results from my my lookup list that include items with ID's > 1000 (in other words the last items added to that lookup list).

My understanding (and please excuse ignorance, I am an SP specialist, but new to PowerApps) is that if delegation was not happening, I would not expect to see any items beyond the first 500 (by ID).

[Shanescows · Accepted solution]

I think the issue is your items property for your combo box is not correct. Let me see if I can recreate this and explain. 

My Datasource is a SharePoint list with a LookUp column in it. Here is my screenshot:

Both show the Value of the Title field. But because I am more precise on the bottom one I don't don't get the silly blue circle. 🙂 

Your Gallery control isn't lying to you. So far you have not made it mad with your items for it so no blue circle. 

Cool? 

[jefferson]

@Shanescows The ShowColumns did the trick! I would love to know how you knew this as I can find nothing to correlate it to delegation issues or indeed very little that defines what it does at all.

Anyway, I hope this helps someone else who experiences delegation issues with SharePoint lookup filters and thanks you once again for all your help 🙂

[Shanescows]

I am glad it worked for you Jefferson. 

Long story short I just played around a bit. I knew that adding a whole data source to a drop-down had to be confusing for the control. PowerApps is super friendly so it did its best to guess what column you wanted to use. Using ShowColumns we just got rid of the guesswork and that pesky LookUp column. If I had to guess your results weren't actually being stopped at 500 items but I am too lazy to test.