I have added Fragment to Activity like
getSupportFragmentManager().beginTransaction()
.add(R.id.container,new MyFragment).commit();
where container is the id of FrameLayout
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
Now how could i get the instance of Fragment in Activity like this
I have to call a method of Fragment A after getting result from Fragment B.
I have created an interface in Fragment B and implemented it in Activity.Now i have to pass the result to Fragment A. I am unable to get the instance of Fragment A.
One thing i don't wanna do is to create a private instance of Fragment A in Activity and call it's method.
Try this
getSupportFragmentManager().beginTransaction()
.add(R.id.container,new MyFragment(),"MyFragment").commit();
for get the fragment
MyFragment frag = ((MyFragment) getSupportFragmentManager().findFragmentByTag("MyFragment"));
Following this link:
All Fragment-to-Fragment communication is done through the associated Activity. Two Fragments should never communicate directly.
Thus I would recommend:
To define a interface in Fragment B.
Implement the interface in activity.
Then eventually, deliver the message to Fragment A.
Code example and reference.
Related
I'm using MVP in my project. I have an activity. Inside this activity I'm showing fragment. Fragment contains some data, edit text, buttons etc. From this fragment it is possible to navigate to another fragment. Here is my code for showing another fragment:
getParentFragmentManager()
.beginTransaction()
.replace(R.id.main_container, secondFragment)
.addToBackStack(null)
.commitAllowingStateLoss();
Next, when I try to go back from fragment 2 to fragment 1, my fragment one is re-created.The method onViewCreated() is called again with saveedInstanceState = null. Also in the onViewCreated() I call presenter.onCreate(savedInstanceState) and because of this, all requests that should be called when I first enter the fragment are re-called when I back to first fragment.
As far as I understand, when calling a .replace(container, fragment), I cannot avoid recreating the fragment view, but in this case, how can I save all my data in the presenter so that I do not re-execute all requests when returning to the fragment?
P.S. With .add() fragment is not recreated. But in my activity I have toolbar with title, and I don't need it to show in my second fragment. When I open my second fragment with .replace() toolbar is not showing, but when open with .add() toolbar is showing.
Use Fragment Result API :
For implemention this method set - setFragmentResultListener - in source fragment and also set - setResult() and finish() - in destination fragment
Note 1 : for having clean code i suggest you to use FragmentTransaction class in:
https://github.com/mahditavakoli1312/FragmentTransaction---mahdi-tavakoli
Note 2 : use Navigation for navigate betwin fragments and activities Instead tranastion
I have an Activity. It adds Fragment A dynamically. Fragment A contains static added (by xml) child Fragment B. How can I pass data from Activity to Fragment B when i add Fragment A to Activity?
I know next approach:
Implement interface getter in Activity and call getter method from Fragment B
I'd like to know, are there another ways to do it?
I tried set arguments from Activity to Fragment A, find Fragment B by child fragment manager and set arguments from Fragment A to Fragment B.
But Fragment B created earlier than Fragment A, so i had exceptions..
Well there are more than one ways to accomplish that. one of the way is
Create a function public void setData(Data data) in your Fragment B
Transfer your data from Activity to Fragment A. Since your Fragment B is added by fragment tag in xml. create ref to your Fragment B object in Fragment A. Now you have the reference to Fragment B in A.
Now Simply call the function (created in Fragment B) in Fragment A and pass the data which you have received by the Activity
Other way..
In Fragment B you can call getActivity() and type cast it in to your Activity class type and call its method which can return the desired data
This sample by google should resolve all your Issues:
https://developer.android.com/training/basics/fragments/communicating.html
You can try EventBus to pass data from Activity to your Fragment B. In your activity call this EventBus.getDefault().post(new MessageEvent());
And then you just need to register EventBus in onCreateView of Fragment B
EventBus.getDefault().register(this);
And then
#Subscribe
public void onEvent(MessageEvent event){
// DO SOMETHING
}
I have two Fragments A and B. I am going from fragment A to Fragment B using Following method.
getActivity().getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new B()).addToBackStack(TAG).commit();
Now I want to send data to from fragment B to Fragment A i.e Previous Fragment.
Can you please give me an idea about how to send data to previous Fragment.
Thanks
Check the documentation about Fragments and its communication.
Do you want to pass info from one fragment to another? One fragment shouldn't know about other fragments. Make the fragment B communicate with its activity through an interface and make the activity pass the data to fragment A
You can communicate between fragments through Activity where you are replacing fragments.
Pass data to activity and then call method of that fragment where you want to update data.
2.Other way you can take a variable in Activity and save the data to this variable and when another fragment (Fragment A) is loaded(Resumed) then show data from Activity variable by getting
((HomeActivity)getActivity).variableName;
You create a subclass of Fragment called MyFragment that A, B are instances of it. Then create a static factory method take a MyFragment as param like:
public static MyFragment newInstance(MyFragment a){
MyFragment b = new MyFragment();
MyFragment b.a = a;
return b;
}
b.a is a field of MyFragment. Then you can use reference a to send data.
is there a way to send some data from an activity to a running fragment?
In my app I'm adding a second fragment over another fragment. I intentionally use the add method instead of the replace method. So now I want to hide my second fragment with
fragmentManager.popBackStack();
and my first fragment reappears. After hiding the second fragment I want to send some data from my activity to the still running frist fragment.
Any idea how to do this? It doesn't work with bundles (put extra), because I don't rebuild the fragment, I just hide the second one!
one simple solution is:
MyFragment oldFragment = (MyFragment) fragmentManager.findFragmentById(R.id.fragment_place);
fragmentManager.popBackStackImmediate();
MyFragment newFragment = (MyFragment)fragmentManager.findFragmentById(R.id.fragment_place);
newFragment.postData(...);
You can use an EventBus library like this one, it's easy to use and very convenient.
You can use tags on the Fragments when you create them to call them when needed.
getFragmentManager().beginTransaction()
.add(R.id.content, new SomeFragment(), SomeFragment.class.getSimpleName())
.commit();
So above I use the simple name of the class to tag the fragment when I create and add it to the activity.
SomeFragment fragment = (SomeFragment) getFragmentManager().findFragmentByTag(SomeFragment.class.getSimpleName());
And I can call it back when I need it and know it is being displayed like above, now I can call send it data like normal by calling a public method in the custom fragment and passing it the data as a param.
Based on the example from http://developer.android.com/training/basics/fragments/communicating.html I tried to reproduce the communication between two fragments which are sub fragments of a larger fragment.
In the example, AB activity contains A fragment and B fragment. But I am trying to achieve the same but in my case AB Fragment contains A fragment and B fragment.
The problem is the overridden method in the AB Fragment never gets called. Does this not work because the containing component is a Fragment and not a Activity like in the example? Am I missing out something here?
If you are referring to onClick() or some other onSomething() handler, then these always get called in the Activity class, not the fragment. So in the example you linked, the onArticleSelected() must remain in the Activity, even if you have nested fragments.
To pass info on to the fragment, you have a few options. One, you can keep a reference to the fragment within the activity. This might be lost if your activity recreates (settings event for example).
The second and better way would be to tag your fragments, and then use findFragmentByTag.
When you add your fragment (notice the parameter "my_fragment" which is the tag I gave to the fragment):
getSupportFragmentManager().beginTransaction().add(R.id.fragment_container, myFragment, "my_fragment").commit();
Or when you replace one fragment with another:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container, myFragment, "my_fragment").comit();
Then, when you want to do something in the fragment from within your onArticleSelected of the activity:
Fragment fragment = getSupportFragmentManger().findFragmentByTag("my_fragment");
if (fragment != null) {
fragment.articleSelected(articleId);
}
You can always use an Interface to communicate between fragments. It is the safest way to do so.