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http_routes

This example illustrates the http_router, http_server, and http_client libraries by defining a small HTTP server with three routes and a client that calls each of them:

• routes is an object that imports the http_router category and implements the http_handler_protocol protocol. It declares three routes using route/4 facts:
  • GET /hello — a plain static route that returns a fixed text response.
  • GET /users/{id:integer} — a route using a typed path-template placeholder; the router extracts and types the path parameter and annotates the request with a path_params/1 property before calling the handler.
  • POST /echo — a route that reads the request body and echoes it back, prefixed with "Echo: ".
• routes_demo is an object that starts a local, loopback HTTP server serving the routes object using the http_server facade, calls each of the three routes using the http_client convenience predicates (get/3 and post/4), prints the normalized responses, and stops the server.

  This example requires a backend Prolog compiler that supports threads, as `http_server::start/4 and http_server::stop/1` run the server concurrently with the client calls.

Loading

| ?- logtalk_load(http_routes(loader)).

Running

| ?- routes_demo::run.
GET /hello -> 200 OK
  Hello from the Logtalk http_router example!
GET /users/42 -> 200 OK
  User #42
POST /echo -> 200 OK
  Echo: Hello, router!
true.