harmony 鸿蒙@system.fetch (Data Request)

2022-08-09
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@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NOTE - The APIs of this module are no longer maintained since API version 6.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 instead.

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

Table 1 Mapping between data and Content-Type

data	Content-Type	Description
string	Not set	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	Not set	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. That is:
{
  "deviceConfig": {
    "default": {
      "network": {
        "cleartextTraffic": true
      }
      ...
    }
  }
  ...
}