Submit and save button in gallery

[Shahin1]

Hi I have save button for gallery which is retrieving data of two columns  n other columns are fille din gallery n saved by each item. 

If user fills all the items in gallery n if he clicks submit button outside gallery  instead of save button, it should throw an error to save the items first. Bcoz in submit function, I have written navigate button n it is an end of the process .. how to write the formula?

Please help me with the formula.

Thanks

[zmansuri]

There is an amazing video by @RezaDorrani 

Power Apps Editable Table/Gallery like Excel (Tutorial) - YouTube

Watch from 22:00

there is concept which checks if the data is saved and provide visual indicator. If you feel this satisfy your requirement. Watch the whole video.

[Shahin1]

I am not working with a collection. Just retrieving data with filter and saving the other columns or items which are not filled. So I need formula without using collections.

[zmorek]

A collection is just a data source; substitute your data source in where he mentions the collection(s).