2 — Routing & Path Parameters

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HTTP Methods

@app.get("/items")          # GET
@app.post("/items")         # POST
@app.put("/items/{id:int}") # PUT
@app.patch("/items/{id:int}")   # PATCH
@app.delete("/items/{id:int}")  # DELETE

# Multiple methods on one handler
@app.route("/items", methods=["GET", "POST"])
async def items(request):
    if request.method == b"POST":
        ...

---

Path Parameters

Declare typed parameters in the URL pattern — they are extracted and injected directly into your handler.

@app.get("/users/{user_id:int}")
async def get_user(request, user_id: int):
    return {"user_id": user_id}   # user_id is already an int

curl http://127.0.0.1:8000/users/42
# {"user_id": 42}

Converters

Converter	Pattern	Example
:int	[0-9]+	/users/42
:float	[0-9.]+	/prices/9.99
:str	[^/]+	/posts/my-slug
:uuid	UUID format	/tasks/550e8400-...
:path	.* (matches /)	/files/a/b/c.txt

@app.get("/posts/{slug:str}")
async def get_post(request, slug: str):
    return {"slug": slug}

@app.get("/tasks/{task_id:uuid}")
async def get_task(request, task_id: str):
    return {"task_id": task_id}

@app.get("/files/{filepath:path}")
async def get_file(request, filepath: str):
    return {"path": filepath}

---

Query Parameters

request.args is a dict[str, list[str]]. Use get_arg() for a single value.

@app.get("/tasks")
async def list_tasks(request):
    page    = int(request.get_arg("page", "1"))
    limit   = int(request.get_arg("limit", "10"))
    status  = request.get_arg("status")           # None if missing

    return {
        "page": page,
        "limit": limit,
        "filter": status,
    }

curl "http://127.0.0.1:8000/tasks?page=2&limit=5&status=done"
# {"page":2,"limit":5,"filter":"done"}

---

Named Routes

Give a route a name to reference it programmatically:

@app.get("/users/{user_id:int}", name="user_detail")
async def get_user(request, user_id: int):
    return {"user_id": user_id}

---

Route Priorities

Static routes always match before dynamic ones. /users/me will always win over /users/{user_id:int}:

@app.get("/users/me")           # static — matches first
async def get_me(request): ...

@app.get("/users/{user_id:int}")  # dynamic — fallback
async def get_user(request, user_id: int): ...

---

404 and 405 Handlers

@app.handle(404)
async def not_found(exc):
    from ember import JSONResponse
    return JSONResponse({"error": "not_found"}, status_code=404)

@app.handle(405)
async def method_not_allowed(exc):
    from ember import JSONResponse
    return JSONResponse({"error": "method_not_allowed"}, status_code=405)

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