CODEWITHSUNDEEP
androidandroid-databindingandroid-viewmodel
Stillie
Stillie

Reputation: 2676

Enable a button when all EditText complete

I would like to enable a AppCompatButton when all fields in a form are complete.

I am using a ViewModel and would like to use Databinding to enable this.

I have 2 methods that fire when text is changed on the views to update an objects data in the viewmodel.

The issue I am running into is when both fields are complete, I need to enable a button on the layout allowing them to proceed.

An example would be log in, when the username and password fields are fulled in, the log in button becomes enabled.

Upvotes: 5

Views: 5018

Answers (2)

aLT
aLT

Reputation: 326

You can use the same solution like here

But if you want use only AndroidArch and DataBinding you can create your own approach like below:

class MyVM : ViewModel() {
    ...
    val mLoginLiveData = MutableLiveData<String>()
    val mPasswordLiveData = MutableLiveData<String>()
    val mLoginPasswordMediator = MediatorLiveData<Boolean>()
    ...
    init {
      mLoginPasswordMediator.addSource(mLoginLiveData) { validateForm() }
      mLoginPasswordMediator.addSource(mPasswordLiveData) { validateForm() }
      ...
    }

    private fun validateForm() {
        // put your validation logic here, and update the following value
        // as `true` or `false` based on validation result
        // mLoginPasswordMediator.value = ...
    }

    override fun onCleared() {
        // DO NOT forget to remove sources from mediator
        mLoginPasswordMediator.removeSource(mLoginLiveData)
        mLoginPasswordMediator.removeSource(mPasswordLiveData)
    }
}

and in your activity class listen your MediatorLiveData:

class MyActivity : AppCompatActivity() {
    ...
    override fun onCreate(savedInstanceState: Bundle?) {
      //Obtain your ViewModel class here
      //Initialize binding here
      ...
      mBinding.lifecycleOwner = this
      mVM.mLoginPasswordMediator.observe(this, Observer { validationResult ->
          mBinding.yourButton.isEnabled = validationResult
      })
    }
}

And didn't forget to use your LiveDatas' in 'your_activity_layout'.xml:

...
//Add your ViewModel class to layout here
<EditText
  ...
  android:text="@={vm.mLoginLiveData}"
  ... />
...
<EditText
  ...
  android:text="@={vm.mPasswordLiveData}"
  ... />
...

Upvotes: 9

Asendo
Asendo

Reputation: 158

To do this you would have to add onEditorActionListener to your editText which you would enable the button lets say for example i have an edit text named password which i want to enable a login button when it is not empty and when the text entered i it is not less than 8 i would validate and enable the button like this:

password.setOnEditorActionListener(new TextView.OnEditorActionListener() {
    @Override
    public boolean onEditorAction(TextView textView, int actionId, KeyEvent keyEvent) {
        if (password.getText().length() > 0  && password.getText.lenght !< 8) {
            //Automatically click button to login
            loginBtn.setEnabled(true);
            return true;
        }
        return false;
    }
});

You can also use a TextWatcher or an addTextChangedListener on the EditText see here for fore details: https://freakycoder.com/android-notes-66-how-to-use-textwatcher-for-more-than-one-edittext-e190b7ae1070

https://www.dev2qa.com/android-enable-disable-button-by-edittext-text-length/

Upvotes: 0

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