1# Component Startup Rules (FA Model) 2 3 4Component startup refers to the behavior of starting or connecting to an application component. 5 6 7- Start the PageAbility and ServiceAbility. For example, you can use **startAbility()**. 8 9- Connect to the ServiceAbility and DataAbility. For example, you can use **connectAbility()** and **acquireDataAbilityHelper()**. 10 11 12To deliver a better user experience, OpenHarmony restricts the following behavior: 13 14 15- A background application randomly displays a dialog box, such as an ads pop-up. 16 17- Background applications wake up each other. This type of behavior occupies system resources and increases power consumption, or even causes system frozen. 18 19- A foreground application randomly redirects to another application, for example, redirecting to the payment page of another application. This type of behavior poses security risks. 20 21 22In view of this, OpenHarmony formulates a set of component startup rules, as follows: 23 24 25- **Before starting a component of another application, verify the visible field of the target component.** 26 - This rule applies only to cross-application scenarios. 27 - If the **visible** field of the target component is **false**, verify the **ohos.permission.START_INVISIBLE_ABILITY** permission. 28 - For details, see [Component Visible Configuration](../quick-start/module-configuration-file.md#abilities). 29 30- **Before starting a component of a background application, verify the BACKGROUND permission.** 31 - An application is considered as a foreground application only when the application process gains focus or its UIAbility component is running in the foreground. 32 - Verify the **ohos.permission.START_ABILITIES_FROM_BACKGROUND** permission. 33 34- **Before starting the ServiceAbility or DataAbility component of an application, verify the AssociateWakeUp field of the target application.** 35 - This rule applies only to cross-application scenarios. 36 - This rule is valid only when the target component is ServiceAbility or DataAbility. 37 - The ServiceAbility and DataAbility of an application can be accessed by others only when **AssociateWakeUp** of the target application is set to **true**. 38 - The **AssociateWakeUp** field can be configured only for preset applications. For other applications, this field is set to **false** by default. 39 40 41> **NOTE** 42> 1. Component startup control has been implemented since OpenHarmony v3.2 Release. 43> 44> 2. The new component startup rules are more strict than the original ones. You must be familiar with the new startup rules to prevent service exceptions. 45 46 47 48 49## Intra-Device Component Startup Rules 50 51 The rules for starting components on the same device vary in the following scenarios: 52 53- Starting a PageAbility 54 55- Starting a ServiceAbility or DataAbility 56 57 58 59 60## Inter-Device Component Startup Rules 61 62 The rules for starting components on a different device vary in the following scenarios: 63 64- Starting a PageAbility 65 66- Starting a ServiceAbility 67 68 69 70
