如何使用Alamofire运行结构化查询？

Question

如下图所示，它在Postman中效果很好。

postman

但是，我的代码不起作用...

func getMy() {
    let projectId = "lolcourt-554c8"
    let url = "https://firestore.googleapis.com/v1/projects/\(projectId)/databases/(default)/documents:runQuery"
    var request = URLRequest(url: URL(string: url)!)
    request.httpMethod = "POST"
    do {
        let post = MyPost(userId: "Mr.Kim")
        request.httpBody = try JSONEncoder().encode(post)
    } catch {
        print("http Body Error")
    }
    AF.request(request).responseString { response in
        print(response)
    }

输出：

success("[{\n  \"error\": {\n    \"code\": 400,\n    \"message\": \"Invalid JSON payload received. Unknown name \\\"{\\\"structuredQuery\\\":{\\\"where\\\":{\\\"fieldFilter\\\":{\\\"field\\\":{\\\"fieldPath\\\":\\\"userID\\\"},\\\"op\\\":\\\"EQUAL\\\",\\\"value\\\":{\\\"stringValue\\\":\\\"Mr.Kim\\\"}}},\\\"orderBy\\\":[{\\\"field\\\":{\\\"fieldPath\\\":\\\"date\\\"},\\\"direction\\\":\\\"DESCENDING\\\"}],\\\"from\\\":[{\\\"collectionId\\\":\\\"lolCourt\\\"}]}}\\\": Cannot bind query parameter. Field \'{\\\"structuredQuery\\\":{\\\"where\\\":{\\\"fieldFilter\\\":{\\\"field\\\":{\\\"fieldPath\\\":\\\"userID\\\"},\\\"op\\\":\\\"EQUAL\\\",\\\"value\\\":{\\\"stringValue\\\":\\\"Mr\' could not be found in request message.\",\n    \"status\": \"INVALID_ARGUMENT\",\n    \"details\": [\n      {\n        \"@type\": \"type.googleapis.com/google.rpc.BadRequest\",\n        \"fieldViolations\": [\n          {\n            \"description\": \"Invalid JSON payload received. Unknown name \\\"{\\\"structuredQuery\\\":{\\\"where\\\":{\\\"fieldFilter\\\":{\\\"field\\\":{\\\"fieldPath\\\":\\\"userID\\\"},\\\"op\\\":\\\"EQUAL\\\",\\\"value\\\":{\\\"stringValue\\\":\\\"Mr.Kim\\\"}}},\\\"orderBy\\\":[{\\\"field\\\":{\\\"fieldPath\\\":\\\"date\\\"},\\\"direction\\\":\\\"DESCENDING\\\"}],\\\"from\\\":[{\\\"collectionId\\\":\\\"lolCourt\\\"}]}}\\\": Cannot bind query parameter. Field \'{\\\"structuredQuery\\\":{\\\"where\\\":{\\\"fieldFilter\\\":{\\\"field\\\":{\\\"fieldPath\\\":\\\"userID\\\"},\\\"op\\\":\\\"EQUAL\\\",\\\"value\\\":{\\\"stringValue\\\":\\\"Mr\' could not be found in request message.\"\n          }\n        ]\n      }\n    ]\n  }\n}\n]")

我认为编码完成了没有任何错误。

if let encoded = try? JSONEncoder().encode(MyPost(userId: "Mr.Kim")) {
        print(String(data: encoded, encoding: .utf8)!)
    }

输出：

{"structuredQuery":{"where":{"fieldFilter":{"field":{"fieldPath":"userID"},"op":"EQUAL","value":{"stringValue":"Mr.Kim"}}},"orderBy":[{"field":{"fieldPath":"date"},"direction":"DESCENDING"}],"from":[{"collectionId":"lolCourt"}]}}

Answer 1

这与参数编码有关，只需添加此标头

request.addValue("application/json", forHTTPHeaderField: "Content-Type")

Answer 2

无需您自己的参数编码，Alamofire具有内置。

AF.request(url: ..., method: .post, parameters: post, encoder: JSONParameterEncoder.default)

这将正确编码任何编码键入JSON。

PS。要打印响应json而不逃脱，我建议print（字符串（Decoding：data，as：utf8.self）为NSString）