I'm trying to set a variable (buttonText) of customView from main_activity.xml but I got this error:
attribute buttonText (aka com.example.testbinding:buttonText) not
found. error: failed linking file resources.
customView.xml
<?xml version="1.0" encoding="utf-8"?>
<layout 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" >
<data>
<variable
name="buttonText"
type="String" />
</data>
<LinearLayout
android:id="#+id/container"
android:orientation="vertical">
<Button
android:id="#+id/button"
android:text="#{buttonText}" />
</LinearLayout>
</layout>
main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<layout 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">
<data>
</data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<com.example.testbinding.CustomView
android:id="#+id/customView"
...
app:buttonText = "Test button text"
...
>
</com.example.testbinding.CustomView>
</android.support.constraint.ConstraintLayout>
</layout>
In this post I found:
In your Custom View, inflate layout however you normally would and
provide a setter for the attribute you want to set:
My CustomView class have a public setter for buttonText property:
public class CustomView extends LinearLayout {
private CustomViewBinding binding;
private String buttonText;
public CustomView(Context context) {
super(context);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
binding = DataBindingUtil.inflate(inflater, R.layout.custom_view, this, true);
}
public String getButtonText() {
return buttonText;
}
public void setButtonText(String buttonText) {
this.buttonText = buttonText;
}
}
Can anyone tell me what's wrong with it?
Or it impossible without BindingAdapter?
binding.setbuttonText("text_button");
instead of
public String getButtonText() {
return buttonText;
}
public void setButtonText(String buttonText) {
this.buttonText = buttonText;
}
Seems I found what was wrong.
If I use a variable declared in parent view - everything is ok. But if I use a value right in property it's don't work.
wrong:
app:buttonText = "Test button text"
app:progressValue = "50"
correct:
<variable
name="viewModel"
type="com.example.testbinding.ViewModel"/>
app:buttonText = "#{viewModel.buttonText}"
app:progressValue = "#{viewModel.progressValue}"
Of course, viewModel must have a defined setter for these properties.
Related
I have a test project where I want to bind the press of a button to trigger a function via the DataBinding Libray and add:command.
Unfortunately, I'm getting the error:
Found data binding errors.
****/ data binding error ****msg:Could not resolve com.example.ckleineidam.testproject.ViewModel.testButton as an accessor or listener on the attribute.
MainActivity:
public class MainActivity extends AppCompatActivity {
ViewModel mModel;
ActivityMainBinding binding;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_main);
binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
mModel = new ViewModel(this);
binding.setViewModel(mModel);
}
}
ViewModel:
public class ViewModel extends BaseObservable {
private static final String TAG = "VIEW_MODEL";
private Context mActivity;
public ViewModel(Context context) {
this.mActivity=context;
}
public void testButton(){
Log.i(TAG, "Button Click");
}
}
activity_main.xml:
<?xml version="1.0" encoding="utf-8"?>
<layout
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"
tools:context=".MainActivity">
<data>
<variable
name="ViewModel"
type="com.example.ckleineidam.testproject.ViewModel" />
</data>
<android.support.constraint.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="title"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="#+id/activation_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Test Button"
android:background="?android:attr/selectableItemBackground"
app:command="#{ViewModel.testButton}"
app:layout_constraintTop_toBottomOf="#id/title" />
</android.support.constraint.ConstraintLayout >
</layout>
The code is also as an example project at Github.
You are getting this error because there is no attribute app:command on a button.
If you are trying to achieve an onClick functionality, you can use android:onClick="#{ViewModel.testButton}" and change your function signature to void testButton(View view).
To use custom attributes, you need to define a binding adapter
I am trying to use data binding in my app, but nothing is shown.
This is what I did:
I created an New Project with an Empty Activity.
I added
dataBinding {
enabled = true
}
to my build.gradle
This is my activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable name="game" type="my.name.bar.Bar"/>
</data>
<android.support.constraint.ConstraintLayout
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"
tools:context="my.name.bar.MainActivity">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#{game.GetFoo()}"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</android.support.constraint.ConstraintLayout>
</layout>
And this is my Bar class
public class Bar {
private String str;
public Bar() {
str = "Foo";
}
public String GetFoo() {
return str;
}
}
But I am only getting a white screen. If I replace the binding with just "Hello World!" then everything works fine. What am I doing wrong?
(promoted from the comment)
You must bind the value. In your case, it is something like this:
ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);
binding.setGame(new Bar());
I have simple layout and viewModel. I want to connect them with each other but they dont connect.Problem of above problem is in logs there is no error and my app also doesn't crash.
Here my layout:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable
name="progressView"
type="uz.iutlab.ictnews.viewModel.ProgressViewModel" />
<variable
name="viewModel"
type="uz.iutlab.ictnews.viewModel.DetailFragmentViewModel" />
</data>
<RelativeLayout
android:id="#+id/activity_detail"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:tools="http://schemas.android.com/tools"
tools:context="uz.iutlab.ictnews.view.fragment.DetailFragment">
<RelativeLayout
android:id="#+id/fragment_detail_post_root"
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="#dimen/collapsing_image_height">
<android.support.design.widget.CollapsingToolbarLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.makeramen.roundedimageview.RoundedImageView
android:id="#+id/fragment_detail_image_post"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"
android:src="#{viewModel.image}"
app:layout_collapseMode="parallax"
app:setContext="#{viewModel.context}" />
<android.support.v7.widget.Toolbar
android:id="#+id/fragment_detail_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_collapseMode="pin" />
<TextView
android:id="#+id/fragment_detail_title_post"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:padding="#dimen/spacing_view_large"
android:text="#{viewModel.title}"
android:textColor="#android:color/white"
android:textSize="#dimen/font_size_title_huge" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
</RelativeLayout>
</RelativeLayout>
Here is my ViewModel class
public class DetailFragmentViewModel extends BaseObservable {
private Post mPost;
private Context mContext;
public DetailFragmentViewModel(Post mPost,Context mContext) {
this.mPost = mPost;
this.mContext = mContext;
}
public String getTitle() {
return mPost.getTitle().getRendered();
}
public Context getContext () {
return mContext;
}
public String getImage() {
if (mPost.getMedia().getSource_url() != null) {
return mPost.getMedia().getSource_url();
} else {
return null;
}
}
#BindingAdapter({"android:src","setContext"})
public static void downloadImage (RoundedImageView imageView,String url,Context context) {
if (url!=null) {
Picasso.with(context).load(url).into(imageView);
} else {
imageView.setImageResource(R.drawable.placeholder);
}
}
}
There is no error, There is no crashes. App works normally but there is no any title , any image.I tried this one instead overriding its method writing own but doesn't work.
#BindingAdapter({"bind:imageUrl","setContext"})
public static void downloadImage (RoundedImageView imageView,String url,Context context) {
if (url!=null) {
Picasso.with(context).load(url).into(imageView);
} else {
imageView.setImageResource(R.drawable.placeholder);
}
}
In addition to above . I also check it with debug, above methods are not called.
You should better remove app:setContext="#{viewModel.context}" and get it from the view in your adapter. Also you need to use attribute names without a namespace; so instead of bind:imageUrl only use imageUrl.
#BindingAdapter("imageUrl")
public static void downloadImage (RoundedImageView imageView, String url) {
if (url != null) {
Picasso.with(imageView.getContext()).load(url).into(imageView);
} else {
imageView.setImageResource(R.drawable.placeholder);
}
}
But since Picasso works asynchronously, you might end up with an image after you already set it to R.drawable.placeholder again.
Eventually you could also have a look at the generated java sources for the binding and see if your BindingAdapter is called somewhere.
try like this:
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:bind="http://schemas.android.com/apk/res-auto"
>
.....
<com.makeramen.roundedimageview.RoundedImageView
android:id="#+id/fragment_detail_image_post"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:adjustViewBounds="true"
android:scaleType="centerCrop"
bind:src="#{viewModel.image}"
app:layout_collapseMode="parallax"
bind:setContext="#{viewModel.context}" />
.....
</layout>
#BindingAdapter({"bind:loadUrl"})
public static void downloadImage(RoundedImageViewimageView, String url) {
if (url != null) {
Picasso.with(imageView.getContext()).load(url).into(imageView);
} else {
imageView.setImageResource(R.mipmap.ic_launcher);
}
}
The problem was not in my ViewModel or in my xml file everything is correct there is no syntax error.Problem is here this is fragment and I have connected them together my fragment with my viewModel.I made mistake in creating binding here you can see it. This is my not working one
FragmentStudentLifeBinding binding = DataBindingUtil.inflate(inflater,R.layout.fragment_student_life,container,false);
Here is correct one
FragmentStudentLifeBinding binding = DataBindingUtil.inflate(inflater,R.layout.fragment_student_life,container,true);
I missed to attach fragment to activity that is why my binding hadn't been working for 21 days.Hope it will help to someone.
Suppose I have this object:
public class Field
{
List<String> list;
public Field()
{
list = new ArrayList();
}
public boolean isOnTheList(String someText)
{
return list.contains(someText);
}
}
Now I want to use this function on a xml with binding like this.
<?xml version="1.0" encoding="utf-8"?>
<layout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<import type="android.view.View"/>
<variable
name="field"
type="com.greendao.db.Field"/>
<variable
name="user"
type="com.package.User"/>
</data>
<LinearLayout
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:visibility="#{field.isOnTheList(user.name)?View.VISIBLE:View.GONE}"
tools:context=".advisor.new_visit_report.activities.FieldsSelectionActivity"> ...
The problem is that is not working. Anyone has already tried this?
If everything else is set correctly, I would suggest to edit your method to return View.VISIBLE or View.GONE directly:
public int isOnTheList(String someText) {
return list.contains(someText) ? View.VISIBLE : View.GONE;
}
Used in xml:
android:visibility="#{field.isOnTheList(user.name)}
The 2 main questions are :
Why ViewDataBinding doesn't have a method like getVariable("variableName") that will look up for a variable and returns it or null if no variable with this name exists.
Is their any way/workaround to achieve this kind of behavior?
So to be more explicit : if I don't know the type of my ViewDataBinding, is their a way to get its variable or I must know its type?
Here is how it is working actually :
I havea layout called my_layout.xml :
<layout>
<data>
<variable
android:name="myVaribale"
android:type="String"/>
</variable>
</data>
<RelativeLayout
android:id="#+id/root_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="#{myVariable}"/>
</RelativeLayout>
<layout>
I inflate an instance of its ViewDataBinding :
MyLayoutBinding binding = (MyLayoutBinding) DataBindingUtil.inflate(inflater, R.layout.my_layout, root, false);
I can get its variable by calling the appropriate method :
String myVariable = binding.getMyVariable();
So this was how to get a variable when we know the type of the ViewDataBinding.
My problem is here :
Let's imagine I have 3 layouts called my_layout_1, my_layout_2, my_layout_3 and those 3 layouts are surrounded by a <layout> tag.
Those 3 layouts has also the same variable (myVariable).
So here are the layouts :
my_layout_1
<layout>
<data>
<variable
android:name="myVariable"
android:type="String"/>
</variable>
</data>
<RelativeLayout
android:id="#+id/root_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="#{myVariable}"
style="#style/my_style_1"/>
</RelativeLayout>
<layout>
my_layout_2
<layout>
<data>
<variable
android:name="myVariable"
android:type="String"/>
</variable>
</data>
<RelativeLayout
android:id="#+id/root_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="#{myVariable}"
style="#style/my_style_2"/>
</RelativeLayout>
<layout>
my_layout_3
<layout>
<data>
<variable
android:name="myVariable"
android:type="String"/>
</variable>
</data>
<RelativeLayout
android:id="#+id/root_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:text="#{myVariable}"
style="#style/my_style_3"/>
</RelativeLayout>
<layout>
So the different layout represent a text with a different style (I know it can be achieved by others way but the goal is just to explain why I need this function getVariable(variableName).
Imagine now that I got a layout called my_text_container which will randomly contain one of the 3 layouts.
my_text_container
<layout>
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
<layout>
So I'll add a text by doing something like this (again, it's just for demonstration purpose) :
MyTextContainerBinding textContainerBinding = (MyTextContainerBinding) DataBindingUtil.inflate(inflater, R.layout.my_text_container, root, false);
int textLayoutRes;
int randomNumber = generateNumberBetween0and2();
switch(randomNumber) {
case 0: textLayoutRes = R.layout.my_layout_1;
break;
case 1: textLayoutRes = R.layout.my_layout_2;
break;
case 2: textLayoutRes = R.layout.my_layout_3;
break;
}
textContainerBinding.getRoot().addView(DataBindingUtil.inflate(inflater, textLayoutRes, root, false));
And finally I want to retrieve myVariable but I don't know if it's a layout 1, 2 or 3. Basically what could be done now is to use instanceof operator to check whether its a type MyLayoutBinding1, MyLayoutBinding2 or MylayoutBinding3. But as I said this use-case is only for demonstration purpose and I could have 999 different layouts.
So what I would like to do is :
ViewDataBinding myLayout = DataBindingUtil.getBinding(textContainerBinding.getRoot().getChildAt(0));
String myVariable = myLayout.getVariable("myVariable");
if(myVariable != null)
Log.d(TAG, "myLayout was MylayoutBinding1 or myLayoutBinding2 or myLayoutBinding3");
else
Log.d(TAG, "mylayout was not one of the 3 layouts");
Sorry for this (very) long post but thank's for reading it and for any future answers !
I am not sure if I get it but what I do is I declare a variable in the layout like this:
<data>
<variable
name="variableName"
type="bla.bla.VariableType"/>
</data>
Then first you get your layout binding in onCreate:
binding = DataBindingUtil.inflate(inflater, R.layout.your_layout, container, false);
Then you should send a variable to the layout in code like:
binding.setVariableName(yourVariable);
Then you can retrieve it like:
binding.getVariableName();
why ViewDataBinding Doesn't have getMethodVariable?
consider the normal scenario without binding. you have a text container layout. how will you include another layout inside it in a normal activity.
my_text_container.xml:(Normal activity)
You inflate this layout to your java file using R.layout.my_text_container, you won't inflate every layout to a different view to access textview inside it. just one inflate and go with it.
So the same procedure is followed in DataBinding as well, when you use include tag ,the respective fields will be inside MyTextContainerLayoutBinding.
you don't have to inflate it again and again with activity name like MyLayout1Binding, MyLayout2Binding. that's why getting variable name become unnecessary over here.
I think adding variability to Binding , will be more helpful in a place where you just want to display data. Data from one model across multiple included layouts,more helpful with Listviews,Recyclerviews(where layout use data from models).
you can't provide different type for different layouts ,if you are going include one layout to another.(Remember that this binds both layout to single name (parent_activity in your case container)).
Eg:
UserProfileModel:
public class UserProfileModel {
String firstname;
String lastname;
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
public String getFirstname() {
return firstname;
}
public void setFirstname(String firstname) {
this.firstname = firstname;
}
}
my_layout_1.xml;
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<data>
<variable name="user"
type="com.hourglass.lingaraj.bindingusingvariables.UserProfileModel" />
</data>
<LinearLayout
android:orientation="vertical"
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:visibility="visible"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#{user.firstname}"
style="#style/mystyle_1"/>
<include layout ="#layout/my_layout_2"
app:user="#{user}" />
</LinearLayout>
</layout>
my_layout_2.xml:
<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
<data>
<variable
name="user"
type="com.hourglass.lingaraj.bindingusingvariables.UserProfileModel"/>
</data>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:visibility="visible"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#{user.lastname}"
style="#style/mystyle_2"/>
</RelativeLayout>
</layout>
MainActivity.java:
public class MainActivity extends AppCompatActivity {
MyLayout1Binding layout_binding;
UserProfileModel data_model;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_layout_1);
data_model = new UserProfileModel();
data_model.setFirstname("Lingaraj");
data_model.setLastname("Sankaravelu");
layout_binding = DataBindingUtil.inflate(getLayoutInflater(),R.layout.my_layout_1,null,false);
layout_binding = DataBindingUtil.setContentView(this,R.layout.my_layout_1);
layout_binding.setUser(data_model);
}
}
As you see we are using only one model to populate data across included layout. So there is no need get Variable name to verify which model is loaded as it's Binded to single layout.
There is no workaround to achieve this, us of I have tried.
So my answer will be No you can't get a variable name from binding
References.
No More findViewById
Android Data Binding: That Thing
Android Data Binding: Adding some variability
Android Data Binding: Express Yourself