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Data Request fetch

Data Request fetch

Importing Modules

import fetch from '@system.fetch'

API

fetch

method

Initiate an asynchronous network data request. The functions of each field in the options parameter are:

  • url: The URL of the website to access.
  • method: Supports 'GET', 'POST', and 'PUT'. The default is 'GET'.
  • header: An object containing HTTP request header information, where keys and values are strings. Typical HTTP header fields can be Authorization, Content-Type, etc.
  • params: Request parameters; all its properties will be set in the URL part of the request.
  • data: The body content in an HTTP POST request.
  • responseType: The response data type in the HTTP request. The default is 'text', and it can have the following values:
    • 'text': The response returns text data, i.e., the data property of the returned data is of type string.
    • 'json': The response returns JSON data; the returned data property will parse the JSON data into the corresponding JavaScript value.
    • arraybuffer: The response returns binary data, i.e., the returned data is stored as an ArrayBuffer object.
  • timeout: The timeout for the request response in milliseconds. The default value is 6000ms6000 \rm ms.

data Parameter

data is the request body and is only used in POST requests. It is typically one of three types: a string, an ArrayBuffer object, or a JSON object. When data is a string or an ArrayBuffer object, the request body will be text or binary data, respectively. When the body is a JSON object, it will be serialized into text form. The serialization format is determined by the Content-Type field of the request method (method parameter):

  • When Content-Type is application/json, the data parameter object is serialized into a JSON string and used as the request body;
  • In other cases, the data parameter object is serialized into the application/x-www-form-urlencoded format.

Warning

Many HTTP APIs use JSON-formatted POST request bodies. Please ensure the Content-Type request header is correctly set to application/json. For details, refer to this example.

Return Value

Returns a Promise object. The properties of the value it fulfills after the request is completed are as follows:

  • code is the server response code; the response code for a successful request is generally 200.
  • header is the server's response header.
  • data is the return value of the request data, the specific content of which is determined by the options.responseType parameter.

When the request fails, the returned Promise object will be rejected.

Usage Instructions

code Response Code

The meanings of the response codes returned by the server are:

  • 200: Indicates a successful request;
  • 1002: Parameter validation error;
  • 1005: Incomplete input parameters;
  • 5000: Request failed, response error;
  • 5001: Failed to read data buffer;
  • 5002: Request failed, response error;
  • Others: Other HTTP/HTTPS response codes, such as 404, etc.

When the response code returned by fetch is 200, it indicates that the network request was successful; other values indicate that an error occurred during the request.

Notes

Examples

GET Request

This is a basic GET request example:

const res = await fetch.fetch({
  url: 'http://www.rt-thread.com/service/rt-thread.txt',
  method: 'GET', // Since the default mode is GET, the method is optional here
  responseType: 'text'
})
console.log(`the status code of the response: ${res.code}`)
console.log(`the data of the response: ${res.data}`)

POST Request

const res = await fetch.fetch({
  url: 'https://www.rt-thread.com/service/echo',
  method: 'POST',
  data: {
    key1: 'hello',
    key2: 'world'
  },
  responseType: 'text'
})
console.log(`the status code of the response: ${res.code}`)
console.log(`the data of the response: ${res.data}`)

POST Request (JSON Body)

Glyphix framework