I suspect there is some reason why he wants the HTML to be on a server. Perhaps it does some processing or loads values from another source. Just filling a text area in a random HTML file is certainly possible but you don’t even need to it with javascript. Just write the HTML out to a file. Later in the project I suspect his textarea will be dynamic.
Well, now David has several options available.
Thanks to all the options you have given me lots to try out.
Actually I would prefer to have the HTML page local to my WebApp and not use a server. This way I can contain everything necessary in the one bundle for the user. For this reason I shall try Michel’s method first.
My WebApp is not nefarious. I have an option in a large application to build invoices in HTML. I wanted to use an HTML builder plugin that allows the user to edit the HTML in ways I cannot in my WebApp. I wanted to pre-populate the text fields with default values, but allow the user to change them. Once done, I hope to return the HTML, merge some fields and display the invoice in either a new browser window as HTML, email to the client or download as a PDF. Every part of this is now working except the planting of text into the text fields and retrieving any new values.
I shall mark Michel’s as the answer in the hope that works, but thanks again to all contributors. I will contribute back if/when I finally solve it.