how to force a text file with a custom extension to open in myApp rather than being displayed as text in Safari

I'd like to hear your ideas/suggestions for a feasible solutions to the following scenario:

There is an external web service that would serve an iPad user a custom format file of my choice/design to be downloaded via the Safari browser on a user's iPad.
The browser would not open this file, but would instead invoke myApp to read it and use its content (the uuid code to initiate its internal processes with its value)

I've looked into this and I know now how to register "myApp" to handle a custom file extension in iOS level. This works fine as long as the file is not a text file (ie if it's a true binary file, I get the "open in myapp" prompt)

As soon as the file is recognized by Safari as text file, its contents gets displayed on the page and the user doesn't get the opportunity to "Open in in myApp" as it does with a binary file of the same extension.

any ideas/suggestions are appreciated to put me on the right track. thank you.

Solution

This has worked for me in /etc/apache2/httpd.conf

<IfModule headers_module>
  <FilesMatch ".custom$">
    Header Set Content-type application/myApp
    Header Set Pragma public
    Header Set Expires 0
    Header Set Cache-Control private
  </FilesMatch>
</IfModule>

The key was setting the Content-type, since Content-Disposition gets ignored in Safari on iOS. Credit goes to Aaron. (sorry I forgot your full name, since the other answer got deleted along with your comment). If you add your answer, I'll switch to it. Thank you.