Keep in mind that you should be treating your Excel file as a data source - not as a working Excel file. Although, technically, you can do so, it is dangerous because you could alter your Excel and you PowerApp no longer functions. So, using PowerApps to assist in creating or filling in Excel to be used as a "final product" is not advised.
Also realize that your data is considered a table when read from Excel, so, if there is an "empty" cell in Excel, it is just an empty field in that record in your PowerApp...yes you could patch/update it and the Excel file would reflect it.
But, again, it's not advised to consider the Excel datasource as a formatted, pretty and usable file. If you want to do that, I would treat your Excel file as a data source and leave it alone. Then create another Excel file that links to the data source and gets its values from there. This way, change that Excel all you want...no harm to PowerApp.
I've noticed the first point already when I edited something directly from it and the app kinda... died on me (with dying dialogue and all the drama :p)
Also, yes, some empty fields might be used like that I think. For example, a boolean "Is it done/completed" might be empty, or perhaps, make it all "no" and then when editing, change to yes if done, possibly.
Uh, I didn't quite understand the last part. How would I go changing one with another source? That inside PowerApps?
No, what I'm suggesting is that you treat your Excel file as a data source ONLY. No formulas in it, no formatting, nothing really but a table - PowerApps will be happy with that.
Then, all your "logic" in your PowerApp.
If you need pretty versions of it, then create another Excel file and do a data connection to the other one. This way the data will come to your new spreadsheet from the original data source. I would NOT consider having the Excel updating and PowerApps updating all the same.
You just have to consider what purpose the Excel serves (the one the user would interact with). If it is a "report" or "snapshot" then treat it as that and get the data from the real Excel source as a data connection. If it is intended to manipulate the data and change content underneath of PowerApps, you might find yourself with broken apps often.
So for example, I would have 2 Excel file: source (from where I would read gallery, for example) called, say, "excel_source_table" and a second one which would be a duplicate called, say, "excel_edits_app". How would I go making changes in a second one? I have not worked with two DB connections at same time in PA so far, so kinda confused there. Would I need to change the DB source in the edit/form view?
No, your first Excel file will be the primary "database". PowerApps will use it as its only datasource.
You would have another Excel file that would also use the original Excel as a data source. This is done within the second Excel file by connecting it to the first. In your second file, you can format and use the data however you like and it will not impact the primary "database" Excel file...which you don't want to happen.
I am kinda not understanding. Wouldn't then the second excel be a mirror from the first one? As in, for example, if in PowerApps I edit a value from zero to 1, the "original" will have that update, and then the mirror too?
Yes, that is correct. Since your data is coming from the "original" in your second file, it would update. However, the term mirror does not apply in this case - it is "Connect". You are connected to the data, how you display, format or use it is up to you. If you're not familiar with connecting to data in Excel, you might want to brush up on it or consider alternate plans for your design. But, the remaining point is...you really don't want to have a "working" Excel file to be your datasource for PowerApps. Can you? Yes, but should you? I'd say no as there is too much room for issue that can quickly break your App. In this scenario, if the requirement is to have an Excel file of the data, then use a data connection to it in a secondary Excel file so as to leave your "master data source" alone for PowerApps to use.
I see, thank you. I think I will just make it so it is not possible, and any changes will have to be written as a comment or a real vs planned date, somewhere else. Will mark answers regarding Qs as answer now, thank you (:
It is answered, however, not sure if opening new thread or not since it is related to original Q:
It seems I was not able to use the date of another date to compare. I threw a label to check if I did it right or not. Using the formula you said:
I replaced "yourDate" with Today(), ending code as:
The label with that code gives me, as in today 03-19-2019, 12.
However, when I tried using that formula and replacing the "yourDate" with one of the dates I have: 'Comienzo Plan', 'Fin Plan' (which are start/end). But, when writing on the "yourDate" part, it only shows the datacards I have used with it in forms, so I can't use it to compare Today() with any of those dates. How should I go with this?
Where are you trying to put the formula? In a Form or in a Screen outside of a Form?
If you're in a Form, you can replace the yourDate's with ThisItem.'Comienzo Plan' etc.
If you're outside of a Form, you'll need to lookup the record in the Form. Typically just use whatever your Formula is for your Item property on the form.
But, feel free to post some formulas and let's see where the problem is. I will say though...the formula (as nasty long as it is) works well. I use it often in places where week numbers are needed.