Can we do this via subclassing LiteralInclude so we don't have to have so much code here?

I know that we have a lot of code, but it is not possible to extend this class. The logic of this directive is contained in one method. There is no method that we can extend to add new expected behavior.

If we subclass we at least don't have to set the option_spec and other class properties.

Which version did you copy from? There are odd/subtle differences from the version linked to

Unless I'm missing something (I've only had a quick look) I think we should be able to do this as something like:

    def run(self):
        _, filename = self.env.relfn2path(self.arguments[0])
        retnode, = super().run()
        container_node = nodes.container("", literal_block=True, classes=["example-block-wrapper"])
        container_node += example_header(filename=filename)
        container_node += retnode
        retnode = container_node
        return [retnode]

?

(I figured there was some auto-formatting going on)

A link to that would more helpful than master :)

The only change in option_spec is the removal of caption right? Basically there is a lot of code here that we haven't really changed, and it's hard to work out what is special and what isn't.

I will prepare a detailed description of the changes that I made in the code of this class tomorrow.

Can you wait with review? I did not think that this change might require such a discussion

I might be over thinking it - still, a comment in the source would help future Us.

Diff changes: https://pastebin.com/W4eHex7C
Line 1-5: I changed the name of the class. No comemnts
Line 6-15: I updated description of class. No comments
Line 16-17: I remove caption. Now, we use a filename as a caption allways.
Line 18-19 At the time of writing PR, there were no validation types in the project.
Line 20-25: There are two changes here.
a) I dropped support for translating the message. We do not support translations in the project.
b) I pass a arguments to logger. Reason available: #4804
Line 26-38.
a) I dropped caption support. It was conflicting with the new header.
b) I added a new header. This uses the file name as the header content.

Unless I'm missing something (I've only had a quick look) I think we should be able to do this as something like:

I did not find the official API to make a distinction. This is just one class and I decided it would be better to copy it. I've done research on how other people implement extensions for this directive and other people also copy the full class code
https://github.com/FabriceSalvaire/sphinx-getthecode/blob/master/sphinxcontrib/getthecode.py#L27-L32