Localize

​

When to use this

• You want the UI Kit to follow the device language.
• You want to force a specific language regardless of device settings.
• You need to override default UI Kit labels with brand-specific wording.
• You want consistent date and time labels across all UI Kit screens.

​

Prerequisites

• CometChat UI Kit for Android is installed and initialized. Use Getting Started if needed.
• You can access an Android Context (Activity or Application) to apply locale changes.
• You can edit res/values/strings.xml in your app module.

​

Quick start

1. Choose a language code from Supported languages.
2. Add a locale call before you render UI Kit screens. File: app/src/main/java/<your_package>/LocalizeActivity.java or app/src/main/java/<your_package>/LocalizeActivity.kt. Use the code in Implementation > Set and read the UI Kit locale.
3. Override UI text keys in res/values/strings.xml if you need custom wording.
4. Rebuild and run the app.
5. Verify that UI Kit labels render in the selected language and your custom strings appear.

​

Core concepts

• CometChatLocalize: Utility class to set and read the UI Kit locale from an Android Context.
• Language.Code: Constants for supported language codes to use with setLocale.
• strings.xml: Android string resources that control the visible text in UI Kit components.
• DateTimeFormatterCallback: Callback interface to control date and time labels like “Today” or “X mins ago”.

​

CometChatLocalize methods

• setLocale(Context context, @Language.Code String language): Sets the UI Kit language using a Language.Code value.
• getLocale(Context context): Returns the current locale country code for the provided context.

​

Supported languages

• Arabic (ar)
• Chinese (zh)
• Chinese (Traditional) (zh-TW)
• Dutch (nl)
• English (en)
• French (fr)
• German (de)
• Hindi (hi)
• Hungarian (hu)
• Italian (it)
• Japanese (ja)
• Korean (ko)
• Lithuanian (lt)
• Malay (ms)
• Portuguese (pt)
• Russian (ru)
• Spanish (es)
• Swedish (sv)
• Turkish (tr)

​

Implementation

​

Set and read the UI Kit locale

• Where to change it: Your Activity or Application class before UI Kit screens are rendered.
• Applies to: All UI Kit screens.
• Default behavior: UI Kit uses the device locale.
• Override: Call CometChatLocalize.setLocale(...) with a Language.Code value.
• Code:

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.cometchat.chatuikit.shared.resources.localise.CometChatLocalize
import com.cometchat.chatuikit.shared.resources.localise.Language

class LocalizeActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        CometChatLocalize.setLocale(this, Language.Code.hi)
        val currentLocale = CometChatLocalize.getLocale(this)

        setContentView(R.layout.activity_localize)
    }
}

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import com.cometchat.chatuikit.shared.resources.localise.CometChatLocalize;
import com.cometchat.chatuikit.shared.resources.localise.Language;

public class LocalizeActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        CometChatLocalize.setLocale(this, Language.Code.hi);
        String currentLocale = CometChatLocalize.getLocale(this);

        setContentView(R.layout.activity_localize);
    }
}

• What this does: Sets the UI Kit language to Hindi for the current context and reads the current locale value for later use.
• Verify: Launch a UI Kit screen and confirm labels display in the selected language.

​

Override UI Kit strings in strings.xml

• Where to change it: app/src/main/res/values/strings.xml in your app module.
• Applies to: All UI Kit components that reference the string key.
• Default behavior: UI Kit uses its internal strings.xml values.
• Override: Add the same key to your app’s strings.xml to override the label.

<resources>
   <string name="cometchat_chats" translatable="true">Chats</string>
   ....
</resources>

• What this does: Shows the default UI Kit label for the conversations list.

<resources>
   <string name="cometchat_chats" translatable="true">Conversations</string>
   ....
</resources>

• What this does: Replaces the UI Kit label with your custom text.

• No UI Kit source code changes required.
• Easy localization using Android resources.
• UI Kit updates do not overwrite your overrides.
• You can tailor text without affecting behavior.

​

Customize date and time labels

• Where to change it: Your UI Kit initialization (where you build UIKitSettings).
• Applies to: All UI Kit screens that display timestamps.
• Default behavior: UI Kit uses its built-in formatter.
• Override: Provide a DateTimeFormatterCallback when building UIKitSettings.
• Code:

import android.content.Context
import android.util.Log
import com.cometchat.chat.core.CometChat
import com.cometchat.chat.exceptions.CometChatException
import com.cometchat.chatuikit.shared.cometchatuikit.CometChatUIKit
import com.cometchat.chatuikit.shared.cometchatuikit.UIKitSettings
import com.cometchat.chatuikit.shared.interfaces.DateTimeFormatterCallback
import java.text.SimpleDateFormat
import java.util.Date
import java.util.Locale

object AppInit {
    fun initUiKitWithDateFormatter(
        context: Context,
        appId: String,
        region: String,
        authKey: String
    ) {
        val uiKitSettings = UIKitSettings.UIKitSettingsBuilder()
            .setAppId(appId)
            .setRegion(region)
            .setDateTimeFormatterCallback(object : DateTimeFormatterCallback {

                private val fullTimeFormatter = SimpleDateFormat("hh:mm a", Locale.getDefault())
                private val dateFormatter = SimpleDateFormat("dd MMM yyyy", Locale.getDefault())

                override fun time(timestamp: Long): String {
                    return fullTimeFormatter.format(Date(timestamp))
                }

                override fun today(timestamp: Long): String {
                    return "Today"
                }

                override fun yesterday(timestamp: Long): String {
                    return "Yesterday"
                }

                override fun lastWeek(timestamp: Long): String {
                    return "Last Week"
                }

                override fun otherDays(timestamp: Long): String {
                    return dateFormatter.format(Date(timestamp))
                }

                override fun minutes(diffInMinutesFromNow: Long, timestamp: Long): String {
                    return "$diffInMinutesFromNow mins ago"
                }

                override fun hours(diffInHourFromNow: Long, timestamp: Long): String {
                    return "$diffInHourFromNow hrs ago"
                }
            })
            .setAuthKey(authKey)
            .build()

        CometChatUIKit.init(context, uiKitSettings, object : CometChat.CallbackListener<String>() {
            override fun onSuccess(s: String) {
                Log.d("CometChatInit", "Success: $s")
            }

            override fun onError(e: CometChatException) {
                Log.e("CometChatInit", "Error: ${e.message}")
            }
        })
    }
}

import android.content.Context;
import android.util.Log;
import com.cometchat.chat.core.CometChat;
import com.cometchat.chat.exceptions.CometChatException;
import com.cometchat.chatuikit.shared.cometchatuikit.CometChatUIKit;
import com.cometchat.chatuikit.shared.cometchatuikit.UIKitSettings;
import com.cometchat.chatuikit.shared.interfaces.DateTimeFormatterCallback;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;

public class AppInit {
    public static void initUiKitWithDateFormatter(
        Context context,
        String appId,
        String region,
        String authKey
    ) {
        UIKitSettings uiKitSettings = new UIKitSettings.UIKitSettingsBuilder()
            .setAppId(appId)
            .setRegion(region)
            .setDateTimeFormatterCallback(new DateTimeFormatterCallback() {

                private final SimpleDateFormat fullTimeFormatter = new SimpleDateFormat("hh:mm a", Locale.getDefault());
                private final SimpleDateFormat dateFormatter = new SimpleDateFormat("dd MMM yyyy", Locale.getDefault());

                @Override
                public String time(long timestamp) {
                    return fullTimeFormatter.format(new Date(timestamp));
                }

                @Override
                public String today(long timestamp) {
                    return "Today";
                }

                @Override
                public String yesterday(long timestamp) {
                    return "Yesterday";
                }

                @Override
                public String lastWeek(long timestamp) {
                    return "Last Week";
                }

                @Override
                public String otherDays(long timestamp) {
                    return dateFormatter.format(new Date(timestamp));
                }

                @Override
                public String minutes(long diffInMinutesFromNow, long timestamp) {
                    return diffInMinutesFromNow + " mins ago";
                }

                @Override
                public String hours(long diffInHourFromNow, long timestamp) {
                    return diffInHourFromNow + " hrs ago";
                }
            })
            .setAuthKey(authKey)
            .build();

        CometChatUIKit.init(context, uiKitSettings, new CometChat.CallbackListener<String>() {
            @Override
            public void onSuccess(String s) {
                Log.d("CometChatInit", "Success: " + s);
            }

            @Override
            public void onError(CometChatException e) {
                Log.e("CometChatInit", "Error: " + e.getMessage());
            }
        });
    }
}

• What this does: Registers a global DateTimeFormatterCallback so all UI Kit timestamps use your formatting rules.
• Verify: Open a conversation list and confirm labels like “Today” or “X mins ago” match your formatter.

​

Customization matrix