1# @system.fetch (Data Request)
2
3> **NOTE**
4> - The APIs of this module are no longer maintained since API version 6. You are advised to use [`@ohos.net.http`](js-apis-http.md).
5>
6> - 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.
7
8
9## Modules to Import
10
11
12```
13import fetch from '@system.fetch';
14```
15
16
17## fetch.fetch<sup>3+</sup>
18
19fetch(options:{ <br>
20&nbsp;&nbsp;url: string;<br>
21&nbsp;&nbsp;data?: string | object;<br>
22&nbsp;&nbsp;header?: Object;<br>
23&nbsp;&nbsp;method?: string;<br>
24&nbsp;&nbsp;responseType?: string;<br>
25&nbsp;&nbsp;success?: (data: FetchResponse) => void;<br>
26&nbsp;&nbsp;fail?: (data: any, code: number) => void;<br>
27&nbsp;&nbsp;complete?: () => void;<br>
28  } ): void
29
30Obtains data through a network.
31
32**System capability**: SystemCapability.Communication.NetStack
33
34**Parameters**
35| Name| Type| Mandatory| Description|
36| -------- | -------- | -------- | -------- |
37| url | string | Yes| Resource URL.|
38| 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**.|
39| header | Object | No| Request header.|
40| method | string | No| Request method. The default value is **GET**. The value can be **OPTIONS**, **GET**, **HEAD**, **POST**, **PUT**, **DELETE **or **TRACE**.|
41| 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.|
42| success | Function | No| Called when the API call is successful. The return value is defined by [FetchResponse](#fetchresponse3).|
43| fail | Function | No| Called when an API call fails.|
44| complete | Function | No| Called when an API call is complete.|
45
46**Table 1** Mapping between data and Content-Type
47
48| data | Content-Type | Description|
49| -------- | -------- | -------- |
50| string | Left unspecified| The default value of Content-Type is **text/plain**, and the value of data is used as the request body.|
51| string | Any type| The value of data is used as the request body.|
52| 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.|
53| Object | application/x-www-form-urlencoded | The value of data is encoded based on the URL rule and is used as the request body.|
54
55## FetchResponse<sup>3+</sup>
56
57**System capability**: SystemCapability.Communication.NetStack
58
59| Name| Type| Readable| Writable| Description|
60| -------- | -------- | -------- | -------- | -------- |
61| code | number | Yes| No| Server status code.|
62| 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.|
63| headers | Object | Yes| No| All headers in the response from the server.|
64
65**Table 2** Mapping between responseType and data in success callback
66
67| responseType | data | Description|
68| -------- | -------- | -------- |
69| 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.|
70| text | string | Text content.|
71| json | Object | A JSON object.|
72
73**Example**
74
75```
76export default {
77  data: {
78    responseData: 'NA',
79    url: "test_url",
80  },
81  fetch: function () {
82    var that = this;
83    fetch.fetch({
84      url: that.url,
85      success: function(response) {
86        console.info("fetch success");
87        that.responseData = JSON.stringify(response);
88      },
89      fail: function() {
90        console.info("fetch fail");
91      }
92    });
93  }
94}
95```
96
97
98> **NOTE**
99>   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:
100>
101> ```
102> {
103>   "deviceConfig": {
104>     "default": {
105>       "network": {
106>         "cleartextTraffic": true
107>       }
108>       ...
109>     }
110>   }
111>   ...
112> }
113> ```
114