Menu
Is there any possibility to use extension function with a databinding? XML:
<data> <import type="my.package.domain.country.model.City.streetName" /> <variable name="city" type="my.package.domain.country.model.City" /> </data> <TextView android:id="@+id/city" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{city.street.streetName()}" /> my.package.domain.country.model.city
data class City( val id: String, val street: Street ) fun City.streetName(): String = street.houseNumber Error
[kapt] An exception occurred: android.databinding.tool.util.LoggedErrorException: Found data binding errors. ****/ data binding error ****msg:cannot find method streetName() in class my.package.domain.country.model.City
Thanks ;)
219
The Data Binding Library is a support library that allows you to bind UI components in your layouts to data sources in your app using a declarative format rather than programmatically. Layouts are often defined in activities with code that calls UI framework methods.
Kotlin extension function provides a facility to "add" methods to class without inheriting a class or using any type of design pattern. The created extension functions are used as a regular function inside that class. The extension function is declared with a prefix receiver type with method name.
In particular, Kotlin extensions let you add functions to a class that you cannot modify. By using them, you will be able to call these new functions as if they were part of the original class. Similarly, you can use this mechanism to add new properties to existing classes. You can also extend Kotlin companion objects.
Extension functions are a cool Kotlin feature that help you develop Android apps. They provide the ability to add new functionality to classes without having to inherit from them or to use design patterns like Decorator.
You have to import CityKt firstly into xml
<import type="my.package.domain.country.model.CityKt" /> int the data section then you can use it like this
<TextView android:id="@+id/city" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="@{CityKt.streetName(city)}" /> If you review CityKt you will see that there is static Java method with City as first argument
195
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
