CMake. Custom find module for FLTK with FetchContent

[Daniel An.]

I plan to write a FLTK find module for my project. So using this module in user code will look like this:

find_package(FLTK <verion> MODULE REQUIRED)

Inside the module, a check will be performed for the availability of the requested version by searching for config file.  Something like this:

unset(FLTK_FIND_VERSION_COMPLETE)

find_package(FLTK CONFIG)
find_package_handle_standard_args(FLTK CONFIG_MODE)

If the requested version is not available, then this module downloads and build FLTK from Github (FetchContent_Declare, FethContent_MakeAvailable).

My question. Is it idiomatically correct to make downloads from the WEB inside the find module? Have you seen anything similar in other projects?

[wea...@gmail.com]

I'm not an FLTK developer, but I have been playing around with cmake too. I think it is not in the scope of a find module to download and install content.

I solved this problem on a higher level in my hobby project. The user has the possibility to use system provided libraries (e.g. FLTK, spdlog, DCMTK, ...), separate option for each (-DUSE_SYSTEM_FLTK=1 or something like this), or if no system provided library is enabled then it downloads, compiles and installs the missing libraries. This is all in the top level cmake.

[Albrecht Schlosser]

On 7/11/24 11:22 wea...@gmail.com wrote:

I'm not an FLTK developer, but I have been playing around with cmake too. I think it is not in the scope of a find module to download and install content.

I agree, and I suggest to ask such questions in the CMake (Discourse) Forum where CMake developers participate.