How do I use databinding to combine a string from resources with a dynamic variable in XML?

Question

I have a TextView which has a hardcoded string and I have a dynamic variable that I want to put at the end of this string. This is my code:

Answer 1

In case if you want to type text in XML, you can use `` quotation.

android:text="@{`Device Name`}"

elsewhere you need to Concat with the String or variable, you can use

android:text="@{`Device Name`.concat(android.os.Build.MANUFACTURER)}"

if you want to Concat string resource instead of the variable you can do,

android:text="@{@string/app_name.concat(`Device Name`)}"

Answer 2

You can do this even simplier:

android:text= "@{@string/generic_text(profile.name)}"

you string should be like this:

<string name="generic_text">My Name is %s</string>

Edit:

1. Of course you can use as many variables as you need:

   android:text= "@{@string/generic_text(profile.firstName, profile.secondName)}"
   
   <string name="generic_text">My Name is %1$s %2$s</string>
   

2. It works just because it's designed in data binding. More in docs: https://developer.android.com/topic/libraries/data-binding/expressions#resources

Answer 3

Use a Binding Adapter.

This sample is written in Kotlin and takes into account that the bound variable can be null:

@BindingAdapter("my_name")
fun TextView.setMyName(name: String?) {
    this.text =
        if (name.isNullOrEmpty()) "" else "${this.context.getString(R.string.Generic_Text)} $name"
}

then use the binding adapter in your XML instead of the android:text property

app:my_name="@{Profile.name}"

Answer 4

You can do this:

android:text= "@{String.format(@string/Generic_Text, Profile.name)}"

if you use string formatting for your Generic_Text string. ex. %s at the end

Answer 5

Many ways to concat strings

1. Using string resource (Recommended because Localization)

android:text= "@{@string/generic_name(user.name)}"

Just make string resource like this.

<string name="generic_name">Hello %s</string>

2. Hard coded concat

android:text="@{`Hello ` + user.name}"/>

This is useful when you need hardcoded append like + for phone number.

3. Using String's concat method

android:text="@{user.firstName.concat(@string/space).concat(user.lastName)}"

Here space is an html entity which is placed inside strings.xml. Because XML does not accept Html entities or special characters directly. (Link Html Entities)

<string name="space">\u0020</string>

4. Using String.format()

android:text= "@{String.format(@string/Hello, user.name)}"

you have to import String class in layout in this type.

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <import type="String" />
    </data>
    <TextView
        android:text= "@{String.format(@string/Hello, user.name)}"
        ... >
    </TextView>
</layout>

5. concat two strings by string resource.

android:text="@{@string/generic_name(user.firstName,user.lastName)}"

In this case put a string resource in strings.xml

<string name="generic_name">%1$s, %2$s</string>

There can be many other ways, choose one you need.

Answer 6

You can also set string resource as parameter to other string resource using formatter like below:

<string name="first_param_text">Hello</string>
<string name="second_param_text">World</string>
<string name="formatted_text">%s lovely %s</string>

and

android:text="@{String.format(@string/formatted_text, @string/first_param_text, @string/second_param_text)}"

"Hello lovely World" will appear on the view.