@system.fetch (Data Request)

NOTE

The APIs of this module are no longer maintained since API version 6. You are advised to use @ohos.net.http.

The initial APIs of this module are supported since API version 3. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import fetch from '@system.fetch';

fetch.fetch³⁺

fetch(options:{
  url: string;
  data?: string|object;
  header?: Object;
  method?: string;
  responseType?: string;
  success?: (data: FetchResponse) => void;
  fail?: (data: any, code: number) => void;
  complete?: () => void;
} ): void

Obtains data through a network.

System capability: SystemCapability.Communication.NetStack

Parameters

Name	Type	Mandatory	Description
url	string	Yes	Resource URL.
data	string \|Object	No	Request parameter, which can be a string or a JSON object. For details, see the mapping between data and Content-Type.
header	Object	No	Request header.
method	string	No	Request method. The default value is GET. The value can be OPTIONS, GET, HEAD, POST, PUT, DELETE or TRACE.
responseType	string	No	Response type. The return type can be text or JSON. By default, the return type is determined based on Content-Type in the header returned by the server. For details, see return values in the success callback.
success	Function	No	Called when the API call is successful. The return value is defined by FetchResponse.
fail	Function	No	Called when an API call fails.
complete	Function	No	Called when an API call is complete.

Table 1 Mapping between data and Content-Type

data	Content-Type	Description
string	Left unspecified	The default value of Content-Type is text/plain, and the value of data is used as the request body.
string	Any type	The value of data is used as the request body.
Object	Left unspecified	The default value of Content-Type is application/x-www-form-urlencoded. The data value is encoded based on the URL rule and appended in the request body.
Object	application/x-www-form-urlencoded	The value of data is encoded based on the URL rule and is used as the request body.

FetchResponse³⁺

System capability: SystemCapability.Communication.NetStack

Name	Type	Readable	Writable	Description
code	number	Yes	No	Server status code.
data	string \|Object	Yes	No	The type of the returned data is determined by responseType. For details, see the mapping between responseType and data in success callback.
headers	Object	Yes	No	All headers in the response from the server.

Table 2 Mapping between responseType and data in success callback

responseType	data	Description
N/A	string	When the type in the header returned by the server is text/, application/json, application/javascript, or application/xml*, the value is the text content.
text	string	Text content.
json	Object	A JSON object.

Example

export default {
  data: {
    responseData: 'NA',
    url: "test_url",
  },
  fetch: function () {
    var that = this;
    fetch.fetch({
      url: that.url,
      success: function(response) {
        console.info("fetch success");
        that.responseData = JSON.stringify(response);
      },
      fail: function() {
        console.info("fetch fail");
      }
    });
  }
}

NOTE HTTPS is supported by default. To support HTTP, you need to add "network" to the config.json file, and set the attribute "cleartextTraffic" to true, as shown below:
{
  "deviceConfig": {
    "default": {
      "network": {
        "cleartextTraffic": true
      }
      ... // Other configuration information
    }
  }
  ... // Other configuration information
}