1# @ohos.app.ability.AbilityStage (AbilityStage) 2 3**AbilityStage** is a runtime class for HAP files. 4 5**AbilityStage** notifies you of when you can perform HAP initialization such as resource pre-loading and thread creation during the HAP loading. 6 7> **NOTE** 8> 9> The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version. 10> The APIs of this module can be used only in the stage model. 11 12## Modules to Import 13 14```ts 15import AbilityStage from '@ohos.app.ability.AbilityStage'; 16``` 17 18## AbilityStage.onCreate 19 20onCreate(): void 21 22Called when the application is created. 23 24**System capability**: SystemCapability.Ability.AbilityRuntime.Core 25 26**Example** 27 28```ts 29import AbilityStage from '@ohos.app.ability.AbilityStage'; 30 31class MyAbilityStage extends AbilityStage { 32 onCreate() { 33 console.log('MyAbilityStage.onCreate is called'); 34 } 35} 36``` 37 38 39## AbilityStage.onAcceptWant 40 41onAcceptWant(want: Want): string; 42 43Called when a specified ability is started. 44 45**System capability**: SystemCapability.Ability.AbilityRuntime.Core 46 47**Parameters** 48 49| Name| Type| Mandatory| Description| 50| -------- | -------- | -------- | -------- | 51| want | [Want](js-apis-app-ability-want.md) | Yes| Want information about the target ability, such as the ability name and bundle name.| 52 53**Return value** 54 55 | Type| Description| 56 | -------- | -------- | 57 | string | Returns an ability ID. If this ability has been started, no new instance is created and the ability is placed at the top of the stack. Otherwise, a new instance is created and started.| 58 59**Example** 60 61```ts 62import AbilityStage from '@ohos.app.ability.AbilityStage'; 63 64class MyAbilityStage extends AbilityStage { 65 onAcceptWant(want) { 66 console.log('MyAbilityStage.onAcceptWant called'); 67 return 'com.example.test'; 68 } 69} 70``` 71 72 73## AbilityStage.onConfigurationUpdate 74 75onConfigurationUpdate(newConfig: Configuration): void; 76 77Called when the global configuration is updated. 78 79**System capability**: SystemCapability.Ability.AbilityRuntime.Core 80 81**Parameters** 82 83 | Name| Type| Mandatory| Description| 84 | -------- | -------- | -------- | -------- | 85 | newConfig | [Configuration](js-apis-app-ability-configuration.md) | Yes| Callback invoked when the global configuration is updated. The global configuration indicates the configuration of the environment where the application is running and includes the language and color mode.| 86 87**Example** 88 89```ts 90import AbilityStage from '@ohos.app.ability.AbilityStage'; 91 92class MyAbilityStage extends AbilityStage { 93 onConfigurationUpdate(config) { 94 console.log('onConfigurationUpdate, language:' + config.language); 95 } 96} 97``` 98 99## AbilityStage.onMemoryLevel 100 101onMemoryLevel(level: AbilityConstant.MemoryLevel): void; 102 103Called when the system has decided to adjust the memory level. For example, this API can be used when there is not enough memory to run as many background processes as possible. 104 105**System capability**: SystemCapability.Ability.AbilityRuntime.Core 106 107**Parameters** 108 109 | Name| Type| Mandatory| Description| 110 | -------- | -------- | -------- | -------- | 111 | level | [AbilityConstant.MemoryLevel](js-apis-app-ability-abilityConstant.md#abilityconstantmemorylevel) | Yes| Memory level that indicates the memory usage status. When the specified memory level is reached, a callback will be invoked and the system will start adjustment.| 112 113**Example** 114 115```ts 116import AbilityStage from '@ohos.app.ability.AbilityStage'; 117 118class MyAbilityStage extends AbilityStage { 119 onMemoryLevel(level) { 120 console.log('onMemoryLevel, level:' + JSON.stringify(level)); 121 } 122} 123``` 124 125## AbilityStage.context 126 127context: AbilityStageContext; 128 129Defines the context of **AbilityStage**. 130 131**System capability**: SystemCapability.Ability.AbilityRuntime.Core 132 133| Name | Type | Description | 134| ----------- | --------------------------- | ------------------------------------------------------------ | 135| context | [AbilityStageContext](js-apis-inner-application-abilityStageContext.md) | The context is obtained in the callback invoked when initialization is performed during ability startup.| 136