Combo Boxes
Allowing a user to add a non-listed value to a multi-value field
I have used cbData for the Combo Box and MultiField for the field name in these examples.
It is easy enough to allow a user to add a custom value to a single select Combo Box with a Data Card Update of
{
Value:
Coalesce(
cbData.SearchText,
cbData.Selected.Value
)
}so it simply uses the SeachText if entered and nothing is selected from it (or uses the selection as normal).
But what about multi-select columns
Choices columns – manage in SharePoint by Admin, but use Text field for Power Apps
If you have read some of this site’s blogs, you may deduce that I have an aversion to complex column types for data fields in Power Apps unless there is a good and necessary reason to use them. On the lesser end of this scale, Choice columns cannot be used to Sort by in a Delegable manner and still in general add a level of complexity that may not be needed if you are only using single choices.
You can of course “hard code” them in Power Apps Drop-down /Combo Box controls, but any changes require design privileges in Power Apps, not something you always want.
So how do you write back to the desirable Text column, while still allowing some management of the Choices without Developer involvement ?
Distinct values for a large list field in Combo Box Items
This idea is an extension of a workaround in Combo Boxes dealing with large lists and the Delegation issues surrounding these and the Distinct function. I have tested this on a large list (30k items) and it works perfectly.
Two caveats here – the number of items displayed in your combo box and the number of filtered items subject to the Distinct function (after the leading letters are entered) will both be subject to your Delegation Limit, but these should not generally be an issue.
Delegation Management – Multi-Choice Combo Boxes
This article looks at some degree of Delegation Management where a Multi-select Combo Box is used to filter a Data Source for any matching values in either a Text or Single Choice field. The output is a Table and can be used as the Items of either a Gallery or a subsequent cascading value Combo Box.
In the below, I have a list of Devices and a field (Text) called DeviceType. I have a Combo Box (cbType) containing a Distinct list of the DeviceType (see this blog on how to do that in a Delegable manner).
Saving and displaying multi-choice Combo Box in a Text field
It is well documented how to save the contents of a multi-select combo box to a Single Line of Text field, but not so how to successfully get the content back into the DefaultSelectedItems of the control.
I will do two examples here (both related) – one on a Choice field and the other on a list of items.