You use the collection the same as you do a data source. In the items property put the collection.
Now the fun begins. the Collection is in memory so when using it you need to think that it is not connected to the data source. You need to patch the results.
In the Gallery I would put the date using the date supplied by the collection plus a textinput that the default is based on the Respnder column. This will be blank until someone puts data in it. Now add a save icon to the same row. On the visibile property to the icon have it set to: If(!isblank(textinput?), false, true) This will mean that if some types something in that box, the icone will appear. On the Onselect to the icon have
Patch(datasource,Lookup(source,ID=Thisitem.ID),{ResponderColumn:Textinput?.Text}) - This will put the text into the datacource row. then I would add another line to the Onselect to run your Collection again and the Gallery will refresh with one less record. Hopw this all makes sense
