I have a SharePoint list that contains a choice column with the 'multiple selection' option turned on. Each item in this list contains data related to preferences for a given user, and the choice column will store the IDs for each of the user's 'favorited' reports.
I would like to write a Patch formula in Power Apps that writes a new value to this column, but retains the existing values. Here is an extract from my current formula, triggered when a user selects the 'Add To Favorites' button, where 'Favorites' is the choice column that already contains values:
Patch(
'Platform User Preferences',
LookUp(
'Platform User Preferences',
UserEmail = User().Email
),
{Favorites: [ThisItem.ID]}
)
Current state, this formula overwrites the existing values in the choice column with the new single value, instead of adding it alongside the existing values.
One approach I have attempted (based on reading similar use cases online) is to create a collection from the Favorites column, add the new value to that collection, then patch the entire collection back to SP. However, I have had similar problems doing this as I do not fully understand the model of a collection that is based on a multi-value choice column. For example, the following also appears to completely wipe the data in the collection, rather than add to it:
ClearCollect(favslist,Filter('Platform User Preferences',UserEmail = User().Email).Favorites);
Collect(favslist, {Value: ThisItem.ID});
Any help with solving this problem would be most appreciated!