从编辑文本创建一个Observable

Question

我正在使用android数据绑定,我想从编辑文本数据创建一个observable,所以我可以使用rxjava对它进行操作.这是我的代码.

XML

<EditText
            android:id="@+id/edit_text_username"
            android:layout_width="match_parent"
            android:addTextChangedListener="@{viewModel.getUsername}"
            android:background="@drawable/border_edit_top"
            android:drawableLeft="@drawable/ic_person_white_24px"
            android:drawablePadding="10dp"
            android:drawableStart="@drawable/ic_person_white_24px"
            android:hint="@string/username"
            android:inputType="text"
            android:paddingEnd="10dp"
            android:paddingLeft="10dp"
            android:paddingRight="10dp"
            android:paddingStart="10dp"
            app:layout_heightPercent="10%" />

ViewModel类

 public TextWatcher getUsername() {
    return new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before, int count) {
            Log.i("username", s.toString());
        }

        @Override
        public void afterTextChanged(Editable s) {

        }
    };
}

我有3个这样的编辑文本,我想使用rx java的combinelatest运算符进行表单验证.我在这个场景中如何实现rx java？

Answer 1

您可以使用RxBinding.这个例子可以帮到你.

//Validate username field
Observable<Boolean> usernameObservable = RxTextView.textChanges(usernameEditText)
                .map(username -> StringUtils.isNotBlank(username) && Validators.validateUsername(username.toString())).skip(1);

//Validate password field
Observable<CharSequence> passwordObservable = RxTextView.textChanges(passwordEditText).skip(1);

//Validate confirm password field
Observable<CharSequence> confirmPasswordObservable = RxTextView.textChanges(confirmPasswordEditText)
                .skip(1);

//Validate password matches field
Observable<Boolean> passwordMatcherObservable = Observable.combineLatest(passwordObservable, confirmPasswordObservable,
                (password, confirmPassword) -> password.toString().equals(confirmPassword.toString())).skip(1);

Observable.combineLatest(passwordMatcherObservable, usernameObservable,
                (passwordMatch, isUsernameValid) -> passwordMatch && isUsernameValid)
                .distinctUntilChanged()
                .subscribe(valid -> createAccountBtn.setEnabled(valid));