PowerApps: Multi value lookups SharePoint in Datacards

Why?

The SharePoint lookup column that allows multiple values to be selected. Nice idea from a SharePoint point of view, but when used in a PowerApps datacard that you want to have default values from a combobox control this may be tricky

What?

An explanation of how you can get multi value lookups from SharePoint to work in a PowerApp that has multiple screens.

How?

In my previous post the single value lookups were clarified: https://knowhere365.space/powerapps-single-value-lookups-sharepoint-in-datacards/ so please check that one first for the context.

Now we want to expand the ListRequests with combox control in Screen 1. In my example I call this combobox: ComboBoxRequestFormats:

The values of this dropdown need to come from a source SharePoint list so the business can manage the options themselves in this list: SourceListRequestFormats. We created a lookup column with the Allow multiple values enabled so the lists are linked: LookUpFormatType. For a best practice (and easy PowerApps management when building), you can use a different column for the lookup instead of the Title column: imagine you have multiple lookups then you need to make sure you are using the correct Title column in the correct syntax.

For submitting the data to your SharePoint list we want to use the Forms Control in Edit mode that is placed in the last screen.

1) The trick is to get every selected item in the Combobox control in a collection so we can use alle data of every selected item. We can achieve this with a ForAll function that we can place in a moment where you change screen or just before you submit the form:

ForAll(
    ComboBoxRequestFormats.SelectedItems,
    Collect(
        COLformatComboboxSelected,
        {
            '@odata.type': "#Microsoft.Azure.Connectors.SharePoint.SPListExpandedReference",
            Id: ID,
            Value: ComboBoxRequestFormats.Selected.Title
        }
    )
);
SubmitForm(FormWithDatacard);
Clear(COLformatComboboxSelected)

The ForAll function puts all the selected items of the control ComboBoxRequestFormats in a temporary new collection COLformatComboboxSelected. In this collection we define three columns to be used in the Datacard of the SharePiont list in next steps:
– @odata.type = a default string for this type of SharePoint columns
– Id = the ID from the SharePoint list
– Value = the property of the Combobox matching the selected column chosen in the multi-select lookup
(very important to change this if you are not using the Title column in the lookup column!)

2) Then we can use the new collection COLformatComboboxSelected to populate the the Default property of the LookUpFormatType Datacard:

COLformatComboboxSelected.Value

3) We also need to change the Update property of the same LookUpFormatType Datacard to submit the data to the SharePoint list preventing it from being blank:

COLformatComboboxSelected

It is important to put the formula of step 1 on the right place to make sure the latest selected items of the ComboBoxRequestFormats will be saved to the list 💪👍