I want to add a button to the system.header/left, which I already did. And when I click that button, I want a file picker popup to choose my CSV.
From the CSV content, I want to create space and pages.
I've browsed through the documents and tutorials, but I can't find anything alike.
Could you point a direction or steps for me? At least, point me to something relevant?.
Here's a short overview:
I'd suggest that you start with the servlet. Provide a couple of lines of test data, to check if your code creates the page structure as expected. Once this works, add the file handling part (from a dedicated html) and pass the data to your existing function. Now, you have the backend and the frontend, so rendering the dialog when your button is clicked, is pretty straight forward.
Make sure to display the button only if the current user has the right to create a space.
Stuff that might help you:
Hope this helps.