Cowboy Routing with constraints keeps failing

Question

I've been trying to use this otherwise simple routing constraint

Dispatch = cowboy_router:compile([{'_',
        [
            {"/tokens/:tokenid",{tokenid,int}, paytoken_handler, []}
        ]}]),

but i keep getting the same error.

My request is curl 10.10.10.56:8080/tokens/1000 -v -H "Content-Type: application/json"

[error] Ranch listener http had connection process started with cowboy_protocol:start_link/4 at <0.97.0> exit with reason: {function_clause,[{cowboy_router,check_constraints,[{tokenid,int},[{tokenid,<<"1000">>}]],[{file,"src/cowboy_router.erl"},{line,276}]},{cowboy_router,match_path,4,[{file,"src/cowboy_router.erl"},{line,264}]},{cowboy_router,execute,2,[{file,"src/cowboy_router.erl"},{line,172}]},{cowboy_protocol,execute,4,[{file,"src/cowboy_protocol.erl"},{line,529}]}]}

NOTE: When i remove the constraint {tokenid, int} it works fine.

Dispatch = cowboy_router:compile([{'_',
        [
            {"/tokens/:tokenid", paytoken_handler, []}
        ]}]),

Any help please.

Thanks.

Answer 1

Edit

It looks like the constraints must be passed as a list of items

{"/:id/:h",[{id,int},{h,int}], toppage_handler, []}

for your case this should work

{"/tokens/:tokenid",[{tokenid,int}], paytoken_handler, []}