Embedding routes within a module via `__init__()`

[mkitti]

On the forums, I encountered some confusion about a @get route at the top level of a package module:
https://discourse.julialang.org/t/difference-between-include-and-using/87795

The problem with putting the routes at the top level of the module is that this is only invoked during precompilation. It is not invoked when the module is loaded.

For the routes to be loaded at module initialization, the routes should be declared from __init__ or some function called from __init__():

module OxygenExample
using Oxygen
using HTTP


function runserver()
    serve()
end

function __init__()
    @get "/greet" function(req::HTTP.Request)
        return "hello world!"
    end
    # routes may also be contained in src/main.jl
    include(joinpath(@__DIR__,"main.jl"))
end

end # module OxygenExample

[ndortega]

Thanks @mkitti for opening this issue, this was the first Oxygen.jl issue on the Julia discourse forums.

Could you clarify the ask? Did you want to add this to the docs? Or are you looking for an alternative way to declare routes? I could look into adding additional route registering functions with a do-end block syntax (same as Genie.jl), the downside is that the first call to each endpoint would be slower because we'd need to store the parsing & mapping strategy at runtime.

The routing macros have the following benefits:

• Provide us a nice syntax to declare routes
• Allow us to generate the parsing logic at build time to parse & map incoming parameters to function handlers with minimal overhead.

[mkitti]

Mainly documenting this would be great.

I'm also thinking about if the macros could be used in a way to create routes during the precompilation phase, but then have them activated on modules load via __init__, but I'm not sure if I have the bandwidth to think about this at the moment.

[ndortega]

Awesome, I can definitely add that to the docs in the next update. I'll keep this issue open until then.

And to your second point, that'd be cool but difficult to implement. As you know, the whole point of macros is to get executed at the precompilation phase.