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Request Hooks ​

After reading this page, you will know how to add hooks to a global or instance scope.

Lifecycle ​

There are 4 hooks in total, before, init, success, and error.

Hooks will be called in the following order:

Handle Request ​

  • before - Instance has been created, atom and configs are available.
  • init - Request has been created, setting configs will not effect the request anymore.

Handle Response ​

  • success - Request has been sent and received a response.
  • failed - Request has been sent but failed.

Usage ​

Different hooks will receive different parameters.

BeforeSend ​

RequestHooks.BeforeSend will receive his own request instance.

  • before
  • init
typescript
type hook = (request: FastjsRequest) => boolean;

RequestSuccess ​

RequestHooks.RequestSuccess will receive the response object.

  • success
typescript
type hook = (response: RequestReturn) => boolean;

RequestFailed ​

RequestHooks.RequestFailed will receive the error and the request instance.

  • failed
typescript
type hook = (error: Error | number | null, request: FastjsRequest) => boolean;

When the error parameter is a Error object, it may be cause by hook interception, network error, and others.

When the error parameter is a number, it is the status code of the response.

Type Declaration ​

typescript
export declare namespace RequestHooks {
  type BeforeSend = (request: FastjsRequest) => boolean;
  type RequestSuccess = (response: RequestReturn) => boolean;
  type RequestFailed = (error: any, request: FastjsRequest) => boolean;
}

export interface RequestHookParam {
  before?: RequestHooks.BeforeSend[] | RequestHooks.BeforeSend;
  init?: RequestHooks.BeforeSend[] | RequestHooks.BeforeSend;
  success?: RequestHooks.RequestSuccess[] | RequestHooks.RequestSuccess;
  failed?: RequestHooks.RequestFailed[] | RequestHooks.RequestFailed;
}

Set Hooks ​

You can set hooks in the global scope or instance scope.

Global Hooks ​

Global hooks will effect all requests.

typescript
request.config.hooks.before = (request: FastjsRequest) => {
  // Disallow all requests
  return false;
};

Instance Hooks ​

Instance hooks will only effect the instance.

typescript
let loading = false;
const getUserData = request
  .create("https://reqres.in/api/users", null, {
    hooks: {
      before: (request: FastjsRequest) => {
        if (loading) return false;
        loading = true;
        return true;
      },
    },
  })
  .then(() => {
    loading = false;
  });

Multi Hooks v1.0.0-alpha.15 ​

Important Note

When you have instance and global hooks at the same time, the instance hooks will be called first.

Set an array of hooks to run multiple hooks. Any hook that returns false will stop the request and will not run the next hooks.

typescript
request.config.hooks.before = [
  () => {
    console.log("First hook");
    return false;
  },
  () => {
    console.log("Second hook"); // This will not be called
    return false;
  },
];
request.get("https://reqres.in/api/users");
// Log: First hook

If you still want to run the next hooks even if the previous hook returns false, you can set GlobalConfig.hooks.runAll to true.

typescript
request.config.hooks.runAll = true;
request.config.hooks.before = [
  () => {
    console.log("First hook");
    return false;
  },
  () => {
    console.log("Second hook"); // This will be called
    return false;
  },
];
request.get("https://reqres.in/api/users");
// Log: First hook
// Log: Second hook

Also, multi hooks can be set in the instance scope.

typescript
request.get("https://reqres.in/api/users", null, {
  hooks: {
    before: [() => {}, () => {}],
  },
});

Example ​

Setting a hook to add a custom referer header.

typescript
request.config.hooks.before = (request: FastjsRequest) => {
  request.config.headers["x-refer"] = location.href;
  return true;
};

Setting some hooks to handle the response.

typescript
request.config.hooks.success = [
  () => {
    console.log("Request success");
    return true;
  },
  (response: RequestReturn) => {
    console.log("Response data", response.data);
    return true;
  },
];

Type Declaration ​

RequestReturn ​

typescript
export interface RequestReturn {
  headers: Array<[string, string]>;
  headersObj: Record<string, string>;
  response: any;
  data: any;
  status: number;
  request: FastjsRequest;
  resend: () => FastjsRequest;
}