We get the result right (Part 2). Fragment Result API

We continue the story about the novelties of the Jetpack library, designed to simplify the exchange of data between the components of an Android application. The first part was devoted to transferring data from Activity and the new Api Activity Result.  

, Google Fragment. “Single Activity” Android-.

“ ?” - . -: ViewModel, Activity, targetFragment . 

Fragment Result Api . , - . , Api , .

1.3.0-alpha04, FragmentManager FragmentResultOwner. , FragmentManger , . , .

, FragmentManager:

• , FragmentManger setFragmentResultListener()
  
  
  
  . 

  
  
  
  
  

• , FragmentManger Bundle, . setFragmentResult()
  
  
  
  . 

  
  
  
  
  

• FragmentManger , Bundle , . 

  
  
  
  
  

:

Fragment Result Api lifecycle- - , STARTED, DESTROYED. 

“ ” FragmentManger Map:

• Map<String, Bundle>
  
  
  
  ,  

  
  
  
  
  

• Map<String, LifecycleAwareResultListener>
  
  
  
  

  
  
  
  
  

FragmentResultListener, FragmentManager Map, , Map. , , FragmentResultListener LifecycleAwareResultListener.

, FragmentManager . , Map .

.

: ProductsFragment , , SortFragment . Fragment Result Api. 

. , . 

1

ProductsFragment, , FragmentManager. - setFragmentResultListener



fragment-ktx, , .

onCreate():

override fun onCreate(savedInstanceState: Bundle?) {
   super.onCreate(savedInstanceState)
   setFragmentResultListener("request_key") { key, bundle ->
        val selectedSort = bundle.getParcelable<Sort>("extra_key")
        //   
   }
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

2

SortFragment , setFragmentResult, Bundle. 

applyButton.setOnClickListener {
   setFragmentResult(
      "request_key",
       bundleOf("extra_key" to getSelectedSort())
   )
}
      
      

        
        
        
      

    
        
        
        
      
      

        
        
        
      

    
    

, Fragment Result Api. 

Api , , FragmentManager  .

FragmentManager

FragmentManager . : parentFragmentManager, childFragmentManager FragmentManager -. , FragmentManager.

master-detail . , FragmentA FragmentB, .

FragmentManager -, .. . FragmentManager requireActivity().supportFragmentManager



parentFragmentManager



.

, , DialogFragment , FragmentA FragmentC. 

, Fragment FragmentA :

• FragmentManager requireActivity().supportFragmentManager

  
  
  
  
  

• FragmentManager FragmentA. , FragmentA childFragmentManager, Fragment parentFragmentManager.

  
  
  
  
  

Lifeycle

, Fragment Result Api lifecycle- - , . . 

- onCreate, STARTED, FragmentManager , - .

STARTED, FragmentManager , ( FragmentManager Map<String, Bundle>, ).

, , “ ” .

, , ( CREATED), , .

, . ? , FragmentManager Map<String, LifecycleAwareListener>, . , .

, : 

• Fragment Result Api , . , targetFrament , targetFrament Deprecated.

  
  
  
  
  

• Api

  
  
  
  
  

• - , view

  
  
  
  
  

• (FragmentManager Parcelable)

  
  
  
  
  

: 

• ,

  
  
  
  
  

• Bundle, . , ClassCastException. 

  
  
  
  
  

, Fragment Result Api , , , .