So far, the button is always disabled no matter what the username edittext value is. Should I be usi...

# android

[리오]

So far, the button is always disabled no matter what the username edittext value is. Should I be using a onchanged listener instead?

[wasyl]

perhaps username is not null, but is empty?

[리오]

!

[wasyl]

Did you try !it.isNullOrEmpty() as condition in the transformation?

[리오]

That was it

[miqbaldc]

You should use ObservableField from data binding class instead of MutableLiveData. Unless you want to use custom class that extend Observable for your username props

ref Observable[PrimitiveType]: https://developer.android.com/topic/libraries/data-binding/observability

ref custom observable:
https://android.jlelse.eu/android-data-binding-observables-part-4-da862a0f402d

@리오

[gildor]

You should use ObservableField from data binding class instead of MutableLiveData

Why so?

[miqbaldc]

So you don't have to to observe in the fragment. Because ObservableField will observe data change on the property without hassle.

*If I get @리오 question correctly. cmiiw

[miqbaldc]

cmiiw @gildor

[miqbaldc]

*unless @리오 wants to implement no logic in the UI at all even a little one my provided solutions might be ugly

[miqbaldc]

// viewmodel.kt
val username = ObservableFieldString("")

// fragment.kt
// do nothing, or process viewmodel.username.get()


// login.xml
<variable name="vm" />

<EditText
android:text="@={vm.username}"
/>
<LoginButton
android:disabled="@{TextUtils.isEmpty(vm.username)}"
>

*I forgot a few syntax above, please change accordingly. Use multi-way e.g (equals sign after @) databinding if I recall correctly, so you don't have to listen for username change.

[gildor]

@miqbaldc MutableLiveData is completely fine and more safe replacement for ObservableField and supported by bindings and one day ObservableField even may be replaced by LiveData

[gildor]

There are even articles like that from DevRelTeam in Google
https://medium.com/androiddevelopers/android-data-binding-library-from-observable-fields-to-livedata-in-two-steps-690a384218f2

[miqbaldc]

I see.

That's an awesome and new info for me. *been dangling with java and building an android library instead of android application.

😂

Thanks @gildor bookmarked.