Show DatePickerFragment in a Fragment Android

Question

I have spent time to search to find the working solution. Some doesn't apply to my case and some doesn't work. That is why I am posting this here.

I am trying to pick a date using the DatePickerFragment in a fragment. I was following the directions explained in Android Developer's site here. I am not getting the code compiled even after following all the steps.

By the way, I am using Navigation Graph to switch between fragment.

Here is what I did and what I faced problem on:

My DatePickerFragment

class DatePickerFragment : DialogFragment(), DatePickerDialog.OnDateSetListener {

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        val c = Calendar.getInstance()
        val year = c.get(Calendar.YEAR)
        val month = c.get(Calendar.MONTH)
        val dayOfMonth = c.get(Calendar.DAY_OF_MONTH)
        return DatePickerDialog(requireActivity(), this, year, month, dayOfMonth)
    }

    override fun onDateSet(view: DatePicker?, year: Int, month: Int, day: Int) {
        // Do something with the date chosen by the user

        // I want to update the button text of my AddNewTransactionFragment with the date picked
    }
}

My AddNewTransactionFragment

The supportFragmentManager is not recognized.

class AddNewTransactionFragment : Fragment(R.layout.fragment_add_new_transaction) {

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        fun showDatePickerDialog(v: View) {
            val newFragment = DatePickerFragment()
            newFragment.show(supportFragmentManager, "datePicker")

            // here this 'supportFragmentManager' is red and the code won't compile with the
            // error: Unresolved reference: supportFragmentManager.
            // and the function showDatePickerDialog is grayed out even though I have
            // android:onClick="showDatePickerDialog" in the corresponding xml file.
        }
    }
}

My xml file of fragment AddNewTransactionFragment

Here, the button android:onClick= attribute has a method but it is red, which is not recognized from the Fragment code.

<?xml version="1.0" encoding="utf-8"?>
<ScrollView 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:layout_height="match_parent"
    android:background="@color/backgroundGray"
    android:padding="25dp"
    tools:context="com.sukajee.splitexpense.AddNewTransactionFragment">


    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:id="@+id/textViewAddNew"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingVertical="10dp"
            android:text="Add New Transaction"
            android:textColor="@color/colorAccent"
            android:textSize="20sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:id="@+id/textViewTransactionDate"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingTop="10dp"
            android:text="Date"
            android:textColor="@color/colorAccent"
            android:textSize="15sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/textViewAddNew" />

        <Button
            android:id="@+id/buttonTransactionDate"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Friday, 01 January 2021"
            app:layout_constraintStart_toStartOf="parent"
            android:onClick="showDatePickerDialog"
            app:layout_constraintTop_toBottomOf="@id/textViewTransactionDate" />

        <EditText
            android:id="@+id/editTextDescription"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ellipsize="end"
            android:hint="Description (Grocery, Food, Laundry etc.)"
            android:maxLines="1"
            android:textColorHint="@color/colorAccent"
            android:textSize="15sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/buttonTransactionDate" />

        <EditText
            android:id="@+id/editTextStore"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ellipsize="end"
            android:hint="Store Name"
            android:maxLines="1"
            android:textColorHint="@color/colorAccent"
            android:textSize="15sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/editTextDescription" />

        <EditText
            android:id="@+id/editTextAmount"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ellipsize="end"
            android:hint="Amount"
            android:inputType="numberDecimal"
            android:maxLines="1"
            android:textColorHint="@color/colorAccent"
            android:textSize="15sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/editTextStore" />

        <EditText
            android:id="@+id/editTextNote"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="20dp"
            android:ellipsize="end"
            android:hint="Note"
            android:inputType="textMultiLine"
            android:textColorHint="@color/colorAccent"
            android:textSize="15sp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/editTextAmount" />

        <Button
            android:id="@+id/buttonSubmit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="Submit"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/editTextNote" />

        <Button
            android:id="@+id/buttonCancel"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="Cancel"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/buttonSubmit" />

        <Button
            android:id="@+id/buttonClear"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="5dp"
            android:text="Clear"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/buttonCancel" />
    </androidx.constraintlayout.widget.ConstraintLayout>
</ScrollView>

This is what explained in the developer's site. What could be the reason for me not getting the required output even after following everything described? Please help.

Answer 1

You have used supportFragmentManager which is available in activity, and also you wrote a method inside another method. Try with this.

class AddNewTransactionFragment : Fragment(R.layout.fragment_add_new_transaction) {

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        someButton.setOnClickListener{v->showDatePickerDialog(v)}
    }

fun showDatePickerDialog(v: View) {
            val newFragment = DatePickerFragment()
            newFragment.show(childFragmentManager, "datePicker")

            // here this 'childFragmentManager' is red and the code won't compile with the
            // error: Unresolved reference: supportFragmentManager.
            // and the function showDatePickerDialog is grayed out even though I have
            // android:onClick="showDatePickerDialog" in the corresponding xml file.
        }
}

Answer 2

You are trying to use the supportFragmentManager from a Fragment but the supportFragmentManager is only available from an Activity specifically an AppCompatActivity or FragmentActivity.

From a Fragment you could use the childFragmentManager as a FragmentManager but i've never tried to open a DialogFragment from a Fragment.