How to send data from DialogFragment to a Fragment?

by

NOTE: aside from one or two Android Fragment specific calls, this is a generic recipe for implementation of data exchange between loosely coupled components. You can safely use this approach to exchange data between literally anything, be it Fragments, Activities, Dialogs or any other elements of your application.

Here’s the recipe:

  1. Create interface (i.e. named MyContract) containing a signature of method for passing the data, i.e. methodToPassMyData(... data);.
  2. Ensure your DialogFragment fullfils that contract (which usually means implementing the interface): class MyFragment extends Fragment implements MyContract {....}
  3. On creation of DialogFragment set your invoking Fragment as its target fragment by calling myDialogFragment.setTargetFragment(this, 0);. This is the object you will be talking to later.
  4. In your DialogFragment, get that invoking fragment by calling getTargetFragment(); and cast returned object to the contract interface you created in step 1, by doing: MyContract mHost = (MyContract)getTargetFragment();. Casting lets us ensure the target object implements the contract needed and we can expect methodToPassData() to be there. If not, then you will get regular ClassCastException. This usually should not happen, unless you are doing too much copy-paste coding 🙂 If your project uses external code, libraries or plugins etc and in such case you should rather catch the exception and tell the user i.e. plugin is not compatible instead of letting the app crash.
  5. When time to send data back comes, call methodToPassMyData() on the object you obtained previously: ((MyContract)getTargetFragment()).methodToPassMyData(data);. If your onAttach() already casts and assigns target fragment to a class variable (i.e. mHost), then this code would be just mHost.methodToPassMyData(data);.
  6. Voilà. You just successfully passed your data from dialog back to invoking fragment.

More Related Contents:

  1. NullPointerException accessing views in onCreate()
  2. Using context in a fragment
  3. Android Activity ClassNotFoundException – tried everything
  4. Replacing a fragment with another fragment inside activity group
  5. Access ViewPager Fragment method from Activity
  6. Setting Custom ActionBar Title from Fragment
  7. Android search with Fragments
  8. onActivityResult() not called in new nested fragment API
  9. Why is accessing TextView of a Fragment inside Activity throwing an error
  10. How to get elements of fragments created by ViewPager in MainActivity?
  11. Android FragmentManager BackStackRecord.run throwing NullPointerException
  12. When is onAttach called during the Fragment LifeCycle? [duplicate]
  13. How to check permission in fragment
  14. RecyclerView not calling onCreateViewHolder or onBindView
  15. Android – How to change fragments in the Navigation Drawer
  16. Android – ImageLoader must be init with configuration before using in UIL
  17. Fragment add or replace not working
  18. onRequestPermissionsResult not being called in dialog fragment
  19. How to change fragments using Android navigation drawer
  20. incompatible types: HomeFragment cannot be converted to Fragment in Android
  21. How to pass data from Recyclerview to Fragment
  22. How to update edittext whenever a quantity is added in android studio
  23. Request runtime permissions from v4.Fragment and have callback go to Fragment?
  24. How to hide the soft keyboard inside a fragment?
  25. No response from jsonArray request [closed]
  26. Override back button to act like home button
  27. javax.* cannot be imported in my Android app?
  28. Android audio FFT to retrieve specific frequency magnitude using audiorecord
  29. Can one class extend two classes?
  30. BroadcastReceiver not receiving download complete action

Leave a Comment