{"record":{"id":"f36ae3e2dd1be3fe","repo":"DioxusLabs/dioxus","slug":"query-parameter-not-found-in-function-argumen","errorCode":null,"errorMessage":"query parameter `{}` not found in function arguments","messagePattern":"query parameter `(.+?)` not found in function arguments","errorType":"validation","errorClass":"syn::Error","httpStatus":null,"severity":"error","filePath":"packages/fullstack-macro/src/lib.rs","lineNumber":698,"sourceCode":"                }\n                PathParam::WildCard(_lit, _, _star, ident, ty, _) => {\n                    let (new_ident, new_ty) = arg_map.remove_entry(ident).ok_or_else(|| {\n                        syn::Error::new(\n                            ident.span(),\n                            format!(\"path parameter `{}` not found in function arguments\", ident),\n                        )\n                    })?;\n                    *ident = new_ident;\n                    *ty = new_ty.0;\n                }\n                PathParam::Static(_lit) => {}\n            }\n        }\n\n        let mut query_params = Vec::new();\n        for param in route.query_params {\n            let (ident, ty) = arg_map.remove_entry(&param.binding).ok_or_else(|| {\n                syn::Error::new(\n                    param.binding.span(),\n                    format!(\n                        \"query parameter `{}` not found in function arguments\",\n                        param.binding\n                    ),\n                )\n            })?;\n            query_params.push(QueryParam {\n                binding: ident,\n                name: param.name,\n                catch_all: param.catch_all,\n                ty: ty.0,\n                arg_idx: ty.1,\n            });\n        }\n\n        // Disallow multiple query params if one is a catch-all\n        if query_params.iter().any(|param| param.catch_all) && query_params.len() > 1 {","sourceCodeStart":680,"sourceCodeEnd":716,"githubUrl":"https://github.com/DioxusLabs/dioxus/blob/393d190a801ccb441d41923e232289b4f8a5c669/packages/fullstack-macro/src/lib.rs#L680-L716","documentation":"Thrown when the query string part of a dioxus-fullstack route (after `?`) declares a parameter that has no matching function argument. Each `?a=1&b` query segment binds to a same-named function argument (`name=binding` syntax lets the URL name differ from the Rust identifier); a missing argument is a compile error.","triggerScenarios":"`#[route(GET, \"/search?q\")]` on a function with no `q` argument; using `?sort=order` (URL name `sort`, binding `order`) when the function argument is named `sort` instead of `order`; adding a query param to the route string during development without updating the signature.","commonSituations":"Iterating on filter/search endpoints and adding URL params faster than handler signatures; misunderstanding the `name=binding` split; renaming Rust arguments without syncing the route string.","solutions":["Add a function argument named exactly like the query parameter (e.g. `q: String`) — it should impl `Deserialize` (or `FromStr`) since it arrives from the query string.","If URL and Rust names must differ, use the `url_name=rust_binding` syntax in the route string: `/search?search=q` binds URL key `search` to argument `q`.","Remove the extra query segment from the route string if it should not be accepted."],"exampleFix":"// before\n#[route(GET, \"/search?q\")]\nasync fn search() -> Vec<Item> { ... }\n\n// after\n#[route(GET, \"/search?q\")]\nasync fn search(q: String) -> Vec<Item> { ... }","handlingStrategy":"validation","validationCode":"# Extend the route checker to query params (bare, name=binding, and catch-all forms):\n# if '?' in route:\n#     q = route.split('?', 1)[1]\n#     need |= {b if (p := seg.split('=')) and (b := p[1] if '=' in seg else seg) and not seg.startswith((':', '{')) else None for seg in q.split('&')} - {None}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Treat `?a&b` in the route string as part of the function contract: N params, N arguments.","Remember `url_name=binding` when the URL key and Rust identifier must differ — do not rename one side silently."],"tags":["dioxus","proc-macro","routes","query-params","compile-time"],"backgroundTag":null,"analyzedSha":"393d190a801ccb441d41923e232289b4f8a5c669","analyzedAt":"2026-08-16T11:27:45.815Z","schemaVersion":2},"datasetVersion":"2026-08-16T13:17:31.715Z"}