Sorry for bad English.
I have BaseFragment. it contains Search View and View Pager and View pager has three fragement like Fragment A,B,C
Fragment B has Listview.
so whenever i am doing search i got search response in Base fragment now what i want to do is push these response to fragment B listview inside viewpager. when every time search action perform and need to refresh listview.
You can get an instance of the fragment you want by calling Fragment manager like this:
CustomFragment fragment = (CustomFragment) getSupportFragmentManager().findFragmentById(R.id.fragment_a);
and then you can call any methods of the fragment like this:
fragment.update(data);
But make sure you check the fragment is not null before calling its methods.
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 with fragment A. Fragment A hosts a list in recyclerview which requires an adapter. When an item from the list is clicked I want to open another fragment, say B, showing additional details about the item.
I can open fragment B in three ways:
From the recyclerview adapter itself where I will have the item position etc.
From fragment A using callback from the adapter, since the adapter has all the required info like position, object etc.
From the activity, again using callback. If i do from the activity, i will have to add callback interface from adapter to fragment A, and finally to the activity. Looks too much.
I want to know what is the best way to open fragment B.
Hey its not good practice to start the fragment from adaptor. because it will be very complex to find the container of fragment. so please always try to start the fragment from main activity which will be parent of all fragment.I hope its help you.
Option 2 is always good approach->
2. From fragment, A using callback from the adapter, since the adapter has all the required info like position, object etc.
"According to MVC pattern adapter is always used for binding view with lists. So adapter should always independent from the fragment so the Single Responsibility Principle will always be handled. So, there should be no dependency from the adapter to fragment but fragment to the adapter. When you call fragment or activity from adapter it will create a cyclic dependency with one another so memory will not clear until you finish the apps. You can call any callback method of the fragment from the adapter which method will call the desired fragment you want."
I have one fragment and that have some view element like textview buttons.
Now My problem is I have some service running background and it is checking data from server(Mysql) when these are some data it tells to Mainactivity.
Now on the basis of result I have to update fragment texeviews buttos.
In fact the fragment is a section of activity.
In the activity,you will get the fragment which involve.
You get the fragment ,so you can do you want to do .
So I currently have an app that has 4 tabs (fragments). They are fragments A,B,C,D, in that order.
Fragment A is the first view opened (along with B because viewPager loads the view before and after the current view).
When I click a button in Fragment A, it sends Data back to MainActivity and then sends that data out to Fragments B and C.
However, this is where the issue comes into play. Since Fragment B was already called, the View isn't updated once I click the button and send the data over, but Fragment C is because the view wasn't called before.
Is there any way that I can remedy this?
You can do it a few ways right.
Just set the data to the fragment and have it update its views
Have all the fragments like B and C register themselves to recieve data from the MainActivity and when MainActivity gets it's data set you tell all the registered receivers of the new data
Recreate the fragment
Use an event bus and tell all subsribers of the new data and MainActivity, Fragment B would get notified of new data. Fragment C would get its data when created by MainActivity
I think this list is pretty endless tbh
The key here is the fragments need to fetch the data from the actvitiy aswell as be updated by the activity. In which case you need to break your UI update behaviour out of onCreateView and into its own updateUI() function. updateUI(MyData) can then be called from onCreateView and also called in a setMyData() on the fragment. Just make sure you check the isAdded flag in setMyData.
This pretty much says it all:
http://developer.android.com/training/basics/fragments/communicating.html
I used a simple fragment communicator that allows the activity to call the fragment, and the same for a fragment to talk to the activity.
You can change the views with the new data based on calling the method from within the activity. The way I do it is set the fragments in the activity then pass them into the page adapter this way I can call the methods within the fragment and implement the fragmentcommunicator interface on the fragments.
You can honestly even avoid the interface if you want, but if you are going to include the same method in all the fragments to talk to them it is easiest.
If you show code, I can show you a quick example.
I have a ViewPager with 3 fragments. One fragment downloads data ​from a website and displays it in TextViews. Now when the user clicks in the menu of the MainActivity on the item "refresh", the fragment should redownloads the data and displays it.
I tried to create a function refresh in the fragment's class and call it from the MainActivity's menu. That worked, but then it crashes because the app can't find the textview. The variable view is empty and it causes a null pointer exception.
What can I do to resolve this?
Many thanks!
From your fragmentactivity,
Fragment tehFraggerz = getSupportFragmentManager().findFragmentByTag(string);
where string is the tag. You set the tag of the fragments in the add, replace, etc methods.
Once you have your fragment, you can do
TextView tehTexterz = (TextView) tehFraggerz.getView().findViewById(R.id.tehText);