Mark Reload Previous Fragment In Back Stack Android

Many developers around the world faces the problem while using fragments when specially you are working with backstack. Let’s take an example when you have a Home fragment and display some information and another Fragment has ability to update, when you open Update fragment on top of it and putted HomeFragment to back stack, Your Next fragment performs some update tasks with apis now when you will press back button and your HomeFragment will be popped from backstack this will contains Old Information, but now you want to make api call to reload updated information.

There can be some more complex cases where you need to mark more than one or specific fragment in backstack.

I have already faced such issues in my production app, so i have build some basic and functionality to solve this.

Sharing with you the workaround

1. Create a MainActivity

package com.codezlab.reloadbackfragment.activities;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import com.codezlab.reloadbackfragment.R;
import com.codezlab.reloadbackfragment.fragments.HomeFragment;
import com.codezlab.reloadbackfragment.fragments.UpdateFragment;

public class MainActivity extends AppCompatActivity implements HomeFragment.OnFragmentInteractionListener, UpdateFragment.OnFragmentInteractionListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initWithHomeFragment();
    }


    private void initWithHomeFragment() {
        String fragmentTag = HomeFragment.class.getSimpleName();
        Fragment fragment = HomeFragment.newInstance(null, null);
        FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();
        localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

    }


    @Override
    public void navigateToUpdateFragment() {
        String fragmentTag = UpdateFragment.class.getSimpleName();
        UpdateFragment fragment = UpdateFragment.newInstance();
        FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();
        localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

    }
}

package com.codezlab.reloadbackfragment.activities;

import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentTransaction;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import com.codezlab.reloadbackfragment.R;

import com.codezlab.reloadbackfragment.fragments.HomeFragment;

import com.codezlab.reloadbackfragment.fragments.UpdateFragment;

public class MainActivity extends AppCompatActivity implements HomeFragment.OnFragmentInteractionListener, UpdateFragment.OnFragmentInteractionListener {

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initWithHomeFragment();

}

private void initWithHomeFragment() {

String fragmentTag = HomeFragment.class.getSimpleName();

Fragment fragment = HomeFragment.newInstance(null, null);

FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();

localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

}

@Override

public void navigateToUpdateFragment() {

String fragmentTag = UpdateFragment.class.getSimpleName();

UpdateFragment fragment = UpdateFragment.newInstance();

FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();

localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:orientation="vertical"
    android:layout_height="match_parent"
    tools:context=".activities.MainActivity">


    <FrameLayout
        android:id="@+id/fragmentContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </FrameLayout>

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:app="http://schemas.android.com/apk/res-auto"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:orientation="vertical"

android:layout_height="match_parent"

tools:context=".activities.MainActivity">

<FrameLayout

android:id="@+id/fragmentContainer"

android:layout_width="match_parent"

android:layout_height="match_parent">

</FrameLayout>

</LinearLayout>

1. Create class BaseFragment.java

package com.codezlab.reloadbackfragment.fragments;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;

public class BaseFragment extends Fragment {

    private boolean reloadRequired = false;


    public boolean isReloadRequired() {
        return reloadRequired;
    }

    public void setReloadRequired(boolean reloadRequired) {
        this.reloadRequired = reloadRequired;
    }


    protected final boolean markFragmentForReloading(String tag) {
        boolean marked = false;
        if (tag == null)
            return marked;

        FragmentManager fragmentManager = getFragmentManager();
        if (fragmentManager != null) {
            Fragment fragment = fragmentManager.findFragmentByTag(tag);

            if (fragment instanceof BaseFragment) {
                ((BaseFragment) fragment).setReloadRequired(true);
                marked = true;
            }

        }
        return marked;
    }


}

package com.codezlab.reloadbackfragment.fragments;

import android.support.v4.app.Fragment;

import android.support.v4.app.FragmentManager;

public class BaseFragment extends Fragment {

private boolean reloadRequired = false;

public boolean isReloadRequired() {

return reloadRequired;

}

public void setReloadRequired(boolean reloadRequired) {

this.reloadRequired = reloadRequired;

}

protected final boolean markFragmentForReloading(String tag) {

boolean marked = false;

if (tag == null)

return marked;

FragmentManager fragmentManager = getFragmentManager();

if (fragmentManager != null) {

Fragment fragment = fragmentManager.findFragmentByTag(tag);

if (fragment instanceof BaseFragment) {

((BaseFragment) fragment).setReloadRequired(true);

marked = true;

}

return marked;

}

3. Create HomeFragment.java

package com.codezlab.reloadbackfragment.fragments;

import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.Toast;

import com.codezlab.reloadbackfragment.R;

/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link HomeFragment.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link HomeFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class HomeFragment extends BaseFragment {
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    private String mParam1;
    private String mParam2;

    private Button button;
    private OnFragmentInteractionListener mListener;

    public HomeFragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment HomeFragment.
     */
    public static HomeFragment newInstance(String param1, String param2) {
        HomeFragment fragment = new HomeFragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_home, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        button = view.findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (mListener != null)
                    mListener.navigateToUpdateFragment();

            }
        });
    }

    @Override
    public void onDestroyView() {
        button.setOnClickListener(null);
        super.onDestroyView();
    }

    @Override
    public void onResume() {
        super.onResume();

        /* check if fragment is  marked for reloading */
        if (isReloadRequired()) {
            /*un-mark to prevent reloading again*/
            setReloadRequired(false);
            Toast.makeText(getActivity(), "You can call api to update your data", Toast.LENGTH_SHORT).show();
        }

    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        public void navigateToUpdateFragment();
    }
}

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package com.codezlab.reloadbackfragment.fragments;

import android.content.Context;

import android.net.Uri;

import android.os.Bundle;

import android.support.annotation.NonNull;

import android.support.annotation.Nullable;

import android.support.v4.app.Fragment;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.Toast;

import com.codezlab.reloadbackfragment.R;

/**

* A simple {@link Fragment} subclass.

* Activities that contain this fragment must implement the

* {@link HomeFragment.OnFragmentInteractionListener} interface

* to handle interaction events.

* Use the {@link HomeFragment#newInstance} factory method to

* create an instance of this fragment.

public class HomeFragment extends BaseFragment {

// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER

private static final String ARG_PARAM1 = "param1";

private static final String ARG_PARAM2 = "param2";

private String mParam1;

private String mParam2;

private Button button;

private OnFragmentInteractionListener mListener;

public HomeFragment() {

// Required empty public constructor

}

/**

* Use this factory method to create a new instance of

* this fragment using the provided parameters.

* @param param1 Parameter 1.

* @param param2 Parameter 2.

* @return A new instance of fragment HomeFragment.

public static HomeFragment newInstance(String param1, String param2) {

HomeFragment fragment = new HomeFragment();

Bundle args = new Bundle();

args.putString(ARG_PARAM1, param1);

args.putString(ARG_PARAM2, param2);

fragment.setArguments(args);

return fragment;

}

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

if (getArguments() != null) {

mParam1 = getArguments().getString(ARG_PARAM1);

mParam2 = getArguments().getString(ARG_PARAM2);

}

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

Bundle savedInstanceState) {

// Inflate the layout for this fragment

return inflater.inflate(R.layout.fragment_home, container, false);

}

@Override

public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {

super.onViewCreated(view, savedInstanceState);

button = view.findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

if (mListener != null)

mListener.navigateToUpdateFragment();

}

});

}

@Override

public void onDestroyView() {

button.setOnClickListener(null);

super.onDestroyView();

}

@Override

public void onResume() {

super.onResume();

/* check if fragment is marked for reloading */

if (isReloadRequired()) {

/*un-mark to prevent reloading again*/

setReloadRequired(false);

Toast.makeText(getActivity(), "You can call api to update your data", Toast.LENGTH_SHORT).show();

}

@Override

public void onAttach(Context context) {

super.onAttach(context);

if (context instanceof OnFragmentInteractionListener) {

mListener = (OnFragmentInteractionListener) context;

} else {

throw new RuntimeException(context.toString()

+ " must implement OnFragmentInteractionListener");

}

@Override

public void onDetach() {

super.onDetach();

mListener = null;

}

/**

* This interface must be implemented by activities that contain this

* fragment to allow an interaction in this fragment to be communicated

* to the activity and potentially other fragments contained in that

* activity.

* <p>

* See the Android Training lesson <a href=

* "http://developer.android.com/training/basics/fragments/communicating.html"

* >Communicating with Other Fragments</a> for more information.

public interface OnFragmentInteractionListener {

public void navigateToUpdateFragment();

}

4. Create UpdateFragment.java

package com.codezlab.reloadbackfragment.fragments;

import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;

import com.codezlab.reloadbackfragment.R;

/**
 * A simple {@link Fragment} subclass.
 * Activities that contain this fragment must implement the
 * {@link UpdateFragment.OnFragmentInteractionListener} interface
 * to handle interaction events.
 * Use the {@link UpdateFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class UpdateFragment extends BaseFragment {

    private OnFragmentInteractionListener mListener;

    private Button button;
    public UpdateFragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @return A new instance of fragment UpdateFragment.
     */
    public static UpdateFragment newInstance() {
        UpdateFragment fragment = new UpdateFragment();
        Bundle args = new Bundle();
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_update, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        button = view.findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                /*supply TagName of the fragment which is added to back stack */
                markFragmentForReloading(HomeFragment.class.getSimpleName());
            }
        });
    }


    @Override
    public void onDestroyView() {
        button.setOnClickListener(null);
        super.onDestroyView();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof OnFragmentInteractionListener) {
            mListener = (OnFragmentInteractionListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
    }
}

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package com.codezlab.reloadbackfragment.fragments;

import android.content.Context;

import android.net.Uri;

import android.os.Bundle;

import android.support.annotation.NonNull;

import android.support.annotation.Nullable;

import android.support.v4.app.Fragment;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import com.codezlab.reloadbackfragment.R;

/**

* A simple {@link Fragment} subclass.

* Activities that contain this fragment must implement the

* {@link UpdateFragment.OnFragmentInteractionListener} interface

* to handle interaction events.

* Use the {@link UpdateFragment#newInstance} factory method to

* create an instance of this fragment.

public class UpdateFragment extends BaseFragment {

private OnFragmentInteractionListener mListener;

private Button button;

public UpdateFragment() {

// Required empty public constructor

}

/**

* Use this factory method to create a new instance of

* this fragment using the provided parameters.

* @return A new instance of fragment UpdateFragment.

public static UpdateFragment newInstance() {

UpdateFragment fragment = new UpdateFragment();

Bundle args = new Bundle();

fragment.setArguments(args);

return fragment;

}

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

}

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

Bundle savedInstanceState) {

// Inflate the layout for this fragment

return inflater.inflate(R.layout.fragment_update, container, false);

}

@Override

public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {

super.onViewCreated(view, savedInstanceState);

button = view.findViewById(R.id.button);

button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

/*supply TagName of the fragment which is added to back stack */

markFragmentForReloading(HomeFragment.class.getSimpleName());

}

});

}

@Override

public void onDestroyView() {

button.setOnClickListener(null);

super.onDestroyView();

}

@Override

public void onAttach(Context context) {

super.onAttach(context);

if (context instanceof OnFragmentInteractionListener) {

mListener = (OnFragmentInteractionListener) context;

} else {

throw new RuntimeException(context.toString()

+ " must implement OnFragmentInteractionListener");

}

@Override

public void onDetach() {

super.onDetach();

mListener = null;

}

/**

* This interface must be implemented by activities that contain this

* fragment to allow an interaction in this fragment to be communicated

* to the activity and potentially other fragments contained in that

* activity.

* <p>

* See the Android Training lesson <a href=

* "http://developer.android.com/training/basics/fragments/communicating.html"

* >Communicating with Other Fragments</a> for more information.

public interface OnFragmentInteractionListener {

}

After building app with above code, you will see HomeFragment has a button to open next UpdateFragment.
Click OpenNextFragment button it will take to UpdateFragment and put current fragment in backstack.

String fragmentTag = UpdateFragment.class.getSimpleName();
        UpdateFragment fragment = UpdateFragment.newInstance();
        FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();
        localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

String fragmentTag = UpdateFragment.class.getSimpleName();

UpdateFragment fragment = UpdateFragment.newInstance();

FragmentTransaction localFragmentTransaction = getSupportFragmentManager().beginTransaction();

localFragmentTransaction.replace(R.id.fragmentContainer, fragment, fragmentTag).addToBackStack(fragmentTag).commit();

I have added fragment in back stack with TagName, so that we could access by its tag.

You can see both Fragments extends BaseFragment class, having function to mark previous fragment for reloading by supplying TagName of the fragment.

I will put complete project code to download shortly, till the time enjoy reading and implementing it.

3 Comments

AffiliateLabz
February 16, 2020 7:13 am

Great content! Super high-quality! Keep it up! 🙂

erotik izle
November 15, 2020 11:57 pm

This is my first time visit at here and i am really pleassant to read all at one place. Neely Fraser Borszcz

erotik izle
November 16, 2020 1:54 pm

Really enjoyed this blog post. Much thanks again. Want more. Maire Duffie Fronnia

Codezlab

Mark Reload Previous Fragment In Back Stack Android

Satvinder Singh

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Reply To erotik izle