(Optional) Using canOpenLink to Check Application Accessibility

When to Use

Before starting application B, application A can call canOpenLink to check whether application B is accessible.

NOTE

The canOpenLink API cannot be used to determine whether the application navigated to via App Linking is accessible.

Constraints

Starting from API version 21, a maximum of 200 URL schemes can be configured in the querySchemes field in the module.json5 file of the entry module. In API version 20 and earlier versions, a maximum of 50 URL schemes can be configured.

Available APIs

canOpenLink is provided by the bundleManager module to check whether a target application is accessible.

For details about the matching rules, see Matching Rules of Explicit Want and Implicit Want.

How to Develop

Procedure for the Caller Application

1. Configure the querySchemes field in the module.json5 file of the entry module to declare the URL schemes.

   {
     "module": {
       //...
       "querySchemes": [
         "app1Scheme"
       ]
     }
   }
   

2. Import the ohos.bundle.bundleManager module.

3. Call canOpenLink.

   import { bundleManager } from '@kit.AbilityKit';
   import { BusinessError } from '@kit.BasicServicesKit';
   import { hilog } from '@kit.PerformanceAnalysisKit';
   
   try {
     let link = 'app1Scheme://test.example.com/home';
     let canOpen = bundleManager.canOpenLink(link);
     hilog.info(0x0000, 'testTag', 'canOpenLink successfully: %{public}s', JSON.stringify(canOpen));
   } catch (err) {
     let message = (err as BusinessError).message;
     hilog.error(0x0000, 'testTag', 'canOpenLink failed: %{public}s', message);
   }
   

Procedure for the Target Application

Configure the uris field in the module.json5 file.

{
  "module": {
    //...
    "abilities": [
      {
        //...
        "skills": [
          {
            // actions cannot be empty. Otherwise, matching the target application fails.
            "actions": [
              "ohos.want.action.home"
            ],
            "uris": [
              {
                "scheme": "app1Scheme",
                "host": "test.example.com",
                "pathStartWith": "home"
              }
            ]
          }
        ]
      }
    ]
  } 
}

FAQ

1. Why is the number of URL schemes configured in querySchemes limited?

   The canOpenLink() API is used to check whether an application is accessible. It indirectly reveals whether a specific application is installed.

   To protect system security and user privacy and to prevent malicious applications from scanning the list of installed applications, you must configure the querySchemes property when using the canOpenLink() API. Starting from API version 21, the maximum number of URL schemes that can be configured is 200. In API version 20 and earlier versions, a maximum of 50 URL schemes can be configured.