Allowing a user to build a list of data for submission to Power Automate.

[Thomas_Gregory]

I am brand new to PowerApps, I have experience as an actual real-life programmer but am working on a project for a small charity which has its own reasons for wanting the solution to be implemented in PowerApps.  I am definitely struggling with the fact that when I hit an obstacle I have no idea whether it is because PowerApps does not want to allow me to implement a solution or simply due to my ignorance of what PowerApps does offer.

My scenario:
Users need a small list of a group of values (First Name, Last Name, Date of Birth) to be checked against the backend to see if they already exist before proceeding to enter a new record.

Functionally what I need would be along the lines of this "To Do List" builder example given in Javascript:
https://data-flair.training/blogs/javascript-project-to-do-list/

The backend logic is straightforward to me.  I just can't find a good way to allow a user to build a list of values before submitting the data.
Every search I've made relating for lists turns up results that are tied to an external data source.  While that option is possible, it would be incredibly bad for an application to need to make calls outside just to build a simple list. So far the best idea I've come up with is to create an arbitrarily large number of rows of text inputs with conditional visibility based on whether the previous inputs have values which looks workable but I find problematic. 

If there's a way to avoid that hack by using something natively supported by PowerApps I'd absolutely want to implement that option instead.

[TheRobRush]

You can just have a collect gather their input controls data into a collection, and if they close the app in between final submissions also have the collection saved into devices memory as a backup. 

When app opens, check if there is a backup.

If so load it, 

If not collect the data into a collection from the source (ie sharepoint)

bring to create new screen

enter name birthday etc

check that against your collection, if its not there add it, if not discard

save collection for backup

when all done

press submit

takes collection, puts it into sharepoint

clear collection

that would be basic idea, can always keep it updated at the source, but also most of the time be solely editing right there on the device itself in its internal memory.