1# @ohos.application.Want (Want) 2 3Want is a carrier for information transfer between objects (application components). Want can be used as a parameter of **startAbility()** to specify a startup target and information that needs to be carried during startup, for example, **bundleName** and **abilityName**, which respectively indicate the bundle name of the target ability and the ability name in the bundle. When ability A needs to start ability B and transfer some data to ability B, it can use Want a carrier to transfer the data. 4 5> **NOTE** 6> 7> The APIs of this module are supported since API version 8 and deprecated since API version 9. You are advised to use [@ohos.app.ability.Want](js-apis-app-ability-want.md) instead. Newly added APIs will be marked with a superscript to indicate their earliest API version. 8 9## Modules to Import 10 11```ts 12import Want from '@ohos.application.Want'; 13``` 14 15## Attributes 16 17**System capability**: SystemCapability.Ability.AbilityBase 18 19| Name | Type | Mandatory| Description | 20| ----------- | -------------------- | ---- | ------------------------------------------------------------ | 21| deviceId | string | No | ID of the device running the ability. If this field is unspecified, the local device is used. | 22| bundleName | string | No | Bundle name.| 23| abilityName | string | No | Name of the ability. If both **bundleName** and **abilityName** are specified in a **Want** object, the **Want** object can match a specific ability. The value of **abilityName** must be unique in an application.| 24| uri | string | No | URI information to match. If **uri** is specified in a **Want** object, the **Want** object will match the specified URI information, including **scheme**, **schemeSpecificPart**, **authority**, and **path**.| 25| type | string | No | MIME type, that is, the type of the file to open, for example, **'text/xml'** and **'image/*'**. For details about the MIME type definition, see https://www.iana.org/assignments/media-types/media-types.xhtml?utm_source=ld246.com. | 26| flags | number | No | How the **Want** object will be handled. By default, numbers are passed in. For details, see [flags](js-apis-ability-wantConstant.md#wantconstantflags).| 27| action | string | No | Action to take, such as viewing and sharing application details. In implicit **Want**, you can define this attribute and use it together with **uri** or **parameters** to specify the operation to be performed on the data. For details, see [action](js-apis-ability-wantConstant.md#wantconstantaction). For details about the definition and matching rules of implicit Want, see [Matching Rules of Explicit Want and Implicit Want](../../application-models/explicit-implicit-want-mappings.md). | 28| parameters | {[key: string]: any} | No | Want parameters in the form of custom key-value (KV) pairs. By default, the following keys are carried:<br>- **ohos.aafwk.callerPid**: PID of the caller.<br>- **ohos.aafwk.param.callerToken**: token of the caller.<br>- **ohos.aafwk.param.callerUid**: UID in [bundleInfo](js-apis-bundle-BundleInfo.md#bundleinfo), that is, the application UID in the bundle information.<br>- **component.startup.newRules**: whether to enable the new control rule.<br>- **moduleName**: module name of the caller. No matter what this field is set to, the correct module name will be sent to the peer.<br>- **ohos.dlp.params.sandbox**: available only for DLP files. | 29| entities | Array\<string> | No | Additional category information (such as browser and video player) of the ability. It is a supplement to the **action** field for implicit Want. and is used to filter ability types. For details, see [entity](js-apis-ability-wantConstant.md#wantconstantentity). | 30 31**Example** 32 33- Basic usage (called in a UIAbility object, where context in the example is the context object of the UIAbility). 34 35 ```ts 36 import Want from '@ohos.application.Want'; 37 import { BusinessError } from '@ohos.base'; 38 import UIAbility from '@ohos.app.ability.UIAbility'; 39 import AbilityConstant from '@ohos.app.ability.AbilityConstant'; 40 41 let want: Want = { 42 'deviceId': '', // An empty deviceId indicates the local device. 43 'bundleName': 'com.example.myapplication', 44 'abilityName': 'EntryAbility', 45 }; 46 class MyAbility extends UIAbility{ 47 onCreate(want: Want, launchParam: AbilityConstant.LaunchParam){ 48 this.context.startAbility(want, (error: BusinessError) => { 49 // Start an ability explicitly. The bundleName, abilityName, and moduleName parameters work together to uniquely identify an ability. 50 console.error(`error.code = ${error.code}`); 51 }); 52 } 53 } 54 ``` 55 56- Data is transferred through user-defined fields. The following data types are supported (called in a UIAbility object, where context in the example is the context object of the UIAbility): 57 58 * String 59 ```ts 60 import Want from '@ohos.application.Want'; 61 62 let want: Want = { 63 bundleName: 'com.example.myapplication', 64 abilityName: 'EntryAbility', 65 parameters: { 66 keyForString: 'str', 67 }, 68 }; 69 ``` 70 * Number 71 ```ts 72 import Want from '@ohos.application.Want'; 73 74 let want: Want = { 75 bundleName: 'com.example.myapplication', 76 abilityName: 'EntryAbility', 77 parameters: { 78 keyForInt: 100, 79 keyForDouble: 99.99, 80 }, 81 }; 82 ``` 83 * Boolean 84 ```ts 85 import Want from '@ohos.application.Want'; 86 87 let want: Want = { 88 bundleName: 'com.example.myapplication', 89 abilityName: 'EntryAbility', 90 parameters: { 91 keyForBool: true, 92 }, 93 }; 94 ``` 95 * Object 96 ```ts 97 import Want from '@ohos.application.Want'; 98 99 let want: Want = { 100 bundleName: 'com.example.myapplication', 101 abilityName: 'EntryAbility', 102 parameters: { 103 keyForObject: { 104 keyForObjectString: 'str', 105 keyForObjectInt: -200, 106 keyForObjectDouble: 35.5, 107 keyForObjectBool: false, 108 }, 109 }, 110 }; 111 ``` 112 * Array 113 ```ts 114 import Want from '@ohos.application.Want'; 115 116 let want: Want = { 117 bundleName: 'com.example.myapplication', 118 abilityName: 'EntryAbility', 119 parameters: { 120 keyForArrayString: ['str1', 'str2', 'str3'], 121 keyForArrayInt: [100, 200, 300, 400], 122 keyForArrayDouble: [0.1, 0.2], 123 keyForArrayObject: [{obj1: 'aaa'}, {obj2: 100}], 124 }, 125 }; 126 ``` 127 * File descriptor (FD) 128 ```ts 129 import fs from '@ohos.file.fs'; 130 import Want from '@ohos.application.Want'; 131 import { BusinessError } from '@ohos.base'; 132 import AbilityConstant from '@ohos.app.ability.AbilityConstant'; 133 import UIAbility from '@ohos.app.ability.UIAbility'; 134 135 136 let fd: number = 0; 137 try { 138 fd = fs.openSync('/data/storage/el2/base/haps/pic.png').fd; 139 } catch(e) { 140 console.error(`openSync fail: ${JSON.stringify(e)}`); 141 } 142 let want: Want = { 143 deviceId: '', // An empty deviceId indicates the local device. 144 bundleName: 'com.example.myapplication', 145 abilityName: 'EntryAbility', 146 parameters: { 147 'keyFd':{'type':'FD', 'value':fd} 148 } 149 }; 150 151 class MyAbility extends UIAbility{ 152 onCreate(want: Want, launchParam: AbilityConstant.LaunchParam){ 153 this.context.startAbility(want, (error: BusinessError) => { 154 // Start an ability explicitly. The bundleName, abilityName, and moduleName parameters work together to uniquely identify an ability. 155 console.error(`error.code = ${error.code}`); 156 }); 157 } 158 } 159 ``` 160 161- For more details and examples, see [Want](../../application-models/want-overview.md). 162 163 <!--no_check--> 164
