The following files have been moved into core_ltix as part of the MDL-79109 migration project work:

• return.php
• request_tool.php

Stepping through return.php (a file that tools could redirect back to), it's clear there's a legacy workflow where it detects a launch error and, depending on a few other things, will prompt the user to make a tool request. A tool request will be sent to the admin user for approval (which, presumably would take place in the old, blue LTI admin UI).

The view generated on return.php looks like this (you'll need to work out what params to use to get to the part which generates this though -fairly easy):

There are a number of reasons we want to remove this feature entirely:

1. This is a feature that is ONLY possible when using an unsigned, legacy tool launch. I.e. no key/secret. This is something we don't expect to see now that LTI has moved on to 1.3 (where key and secret don't exist). In fact, it's likely nobody even knows this 'feature' exists.
2. This feature depends on the tool instance having a toolurl, something which isn't possible any more since 4.3, since tools must be prior-configured now (and the url will exist on the tool type, not the tool instance).
3. The advice the return.php view gives (see above) isn't accurate any more. You cannot just enter the key/secret into the instance form any more (since 4.3).
4. This feature likely hasn't worked in many years and definitely doesn't work now.
5. This feature isn't tested in any way. No behat, no MDLQA, nothing.

I think it's time to remove this code. I suspect we want to keep some part of the return.php, just the bits that will redirect you back to the course home or whatever, but remove the parts dealing with the request tool feature.

This will involve:

• Removal of request_tool.php
• Remove any calling code in return.php (this is the only place request_tool.php is referenced)
• Deprecate any lang strings which are part of this process and this process only.
• Deprecate the moodle/ltix:requesttool capability.
• Sanity check on return.php