OpenHarmony @CnapData

Users often need to share data (such as a text or an image) from one application to another. The following uses PDF file sharing as an example to describe how to use Want to share data between applications.

Data sharing requires two UIAbility components (one for the sharing party and the other for the shared party) and one system component (used as the application sharing box). When the sharing party initiates data sharing by calling startAbility(), the system implicitly matches and displays all applications that support the type of data to share. After the user selects an application, the system starts the application to complete data sharing.

In this section, data sharing is triggered by touching a button. You can use other ways to trigger data sharing during application development. This section focuses on how to configure Want to implement data sharing.

The following actions are involved for data sharing:

ohos.want.action.select: action of starting the application sharing box.
ohos.want.action.sendData: action of sending a single data record, that is, transferring data to the shared party.

The sharing party starts an application sharing box and transfers the data to the shared party. Therefore, Want of the sharing party must be nested at two layers. In the first layer, implicit Want is used together with the ohos.want.action.select action to display the application sharing box. In the second layer, the data to share is declared

in the custom field parameters, and then the Want that includes the ohos.want.action.sendData action and the parameters field is transferred to the application sharing box. The shared party obtains the shared data from parameters.

import common from '@ohos.app.ability.common';

let fileType = 'application/pdf';
let fileName = 'TestFile.pdf';
let fileFd = -1; // Obtain the file descriptor (FD) of the file to share.
let fileSize; // Obtain the size of the file to share.

function implicitStartAbility() {
  let context = getContext(this) as common.UIAbilityContext;
  let wantInfo = {
    / This action is used to implicitly match the application sharing box.
    action: 'ohos.want.action.select',
    // This is the custom parameter in the first layer of Want,
    / which is intended to add information to the application sharing box.
    parameters: {
      // MIME type of PDF.
      'ability.picker.type': fileType,
      'ability.picker.fileNames': [fileName],
      'ability.picker.fileSizes': [fileSize],
      // This is nested Want ,which will be directly sent to the selected application.
      'ability.want.params.INTENT': {
        'action': 'ohos.want.action.sendData',
        'type': 'application/pdf',
        'parameters': {
          'keyFd': { 'type': 'FD', 'value': fileFd }
        }
      }
    }
  }
  context.startAbility(wantInfo).then(() => {
    ...
  }).catch((err) => {
    ...
  })
}

NOTE

Data sharing can be implemented only in FD format. For details about how to obtain the FD and file name, see File Management.

In the preceding code, under the custom field parameters, the following ability.picker.* fields are used to pass the information to be displayed on the application sharing box:

ability.picker.type: file type icon.
ability.picker.fileNames: file name.
ability.picker.fileSizes: file size, in bytes.
ability.picker.fileNames and ability.picker.fileSizes are arrays and have a one-to-one mapping.

The following figure shows an example.

Shared Party

To enable the shared party to identify the shared content, configure skills in the module.json5 file of the UIAbility of the shared party. The actions and type fields in uris match the action and type fields in ability.want.params.INTENT of the sharing party, respectively.

{
  "module": {
    ...
    "abilities": [
      {
        ...
        "skills": [
          {
            ...
            "actions": [
              "action.system.home",
              "ohos.want.action.sendData"
              ...
            ],
            "uris": [
              {
                "type": "application/pdf"
              },
            ]
          }
        ]
      }
    ]
  }
}

After the user selects an application, the Want nested in the ability.want.params.INTENT field is passed to that application. After the UIAbility of the application starts, the application obtains want information from onCreate() or onNewWant().

The following is an example of the Want obtained. You can use the FD of the shared file to perform required operations.

{
    "deviceId": "",
    "bundleName": "com.example.myapplication",
    "abilityName": "EntryAbility",
    "moduleName": "entry",
    "uri": "",
    "type": "application/pdf",
    "flags": 0,
    "action": "ohos.want.action.sendData",
    "parameters": {
        "component.startup.newRules": true,
        "keyFd": {
            "type": "FD",
            "value": 36
        },
        "mime-type": "application/pdf",
        "moduleName": "entry",
        "ohos.aafwk.param.callerPid": 3488,
        "ohos.aafwk.param.callerToken": 537379209,
        "ohos.aafwk.param.callerUid": 20010014
    },
    "entities": []
}

Using Want to Share Data Between Applications

Sharing Party

Shared Party