Case insensitive query parameters

[lorenzori]

Hi, thank you for this awesome tool!

Some client applications require URL query parameters to be case-insensitive, so I have added a middleware to make all query parameters in the request lowercase following an example from an issue in FastAPI.

With this PR for example both https://host/cog/WMTSCapabilities.xml?url=path/to/cog/...tif and https://host/cog/WMTSCapabilities.xml?URL=path/to/cog/...tif
will work.

I am not 100% the WMTS standard says anything about this so happy with any feedback.

[vincentsarago]

🙏 thanks for the PR @lorenzori

As I said in the comment, I'm not 💯 sure we want to add this middleware by default but I think it's fine to add it in the code so people can add it to their own application.

The titiler.application module aims to be a demo and we highly suggest that titiler users create their own application.

I opened another issue #322 because mixing lowercase/uppercase will break the tilejson and wmts endpoints.

[lorenzori]

hey @vincentsarago thanks for the feedback! I have made the LowerCaseQueryStringMiddleware middleware optional as suggested using flag TITILER_API_LOWER_CASE_QUERY_PARAMETERS.

We have looked into making only the query keys lowercase instead of the entire query to avoid breaking the other endpoints and tests pass now locally, however is a bit of a hack as I didn't find an elegant solution with Starlette's Request.

[vincentsarago]

🙏 thanks @lorenzori, I added tests and fixed some format errors