feat: add isLanguageSupported method (#58)

README.md

@@ -109,6 +109,7 @@ const getSupportedVoices = async () => {
 * [`stop()`](#stop)
 * [`getSupportedLanguages()`](#getsupportedlanguages)
 * [`getSupportedVoices()`](#getsupportedvoices)
+* [`isLanguageSupported(...)`](#islanguagesupported)
 * [`openInstall()`](#openinstall)
 * [Interfaces](#interfaces)
 
@@ -149,7 +150,7 @@ Stops the TTS engine.
 getSupportedLanguages() => Promise<{ languages: string[]; }>
 ```
 
-Returns a list of supported languages.
+Returns a list of supported BCP 47 language tags.
 
 **Returns:** <code>Promise&lt;{ languages: string[]; }&gt;</code>
 
@@ -169,6 +170,23 @@ Returns a list of supported voices.
 --------------------
 
 
+### isLanguageSupported(...)
+
+```typescript
+isLanguageSupported(options: { lang: string; }) => Promise<{ supported: boolean; }>
+```
+
+Checks if a specific BCP 47 language tag is supported.
+
+| Param         | Type                           |
+| ------------- | ------------------------------ |
+| **`options`** | <code>{ lang: string; }</code> |
+
+**Returns:** <code>Promise&lt;{ supported: boolean; }&gt;</code>
+
+--------------------
+
+
 ### openInstall()
 
 ```typescript

android/src/main/java/com/getcapacitor/community/tts/TextToSpeech.java

@@ -134,11 +134,9 @@ public boolean isAvailable() {
     }
 
     public boolean isLanguageSupported(String lang) {
-        Set<Locale> supportedLocales = tts.getAvailableLanguages();
-        if (supportedLocales.contains(Locale.forLanguageTag(lang))) {
-            return true;
-        }
-        return false;
+        Locale loc = Locale.forLanguageTag(lang);
+        int result = tts.isLanguageAvailable(loc);
+        return result == tts.LANG_AVAILABLE || result == tts.LANG_COUNTRY_AVAILABLE || result == tts.LANG_COUNTRY_VAR_AVAILABLE;
     }
 
     public void onDestroy() {

android/src/main/java/com/getcapacitor/community/tts/TextToSpeechPlugin.java

@@ -100,6 +100,19 @@ public void getSupportedVoices(PluginCall call) {
         }
     }
 
+    @PluginMethod
+    public void isLanguageSupported(PluginCall call) {
+        String lang = call.getString("lang", "");
+        try {
+            boolean isLanguageSupported = implementation.isLanguageSupported(lang);
+            JSObject ret = new JSObject();
+            ret.put("supported", isLanguageSupported);
+            call.resolve(ret);
+        } catch (Exception ex) {
+            call.reject(ex.getLocalizedMessage());
+        }
+    }
+
     @PluginMethod
     public void openInstall(PluginCall call) {
         try {

ios/Plugin/TextToSpeech.swift

@@ -49,9 +49,9 @@ import Capacitor
         })
     }
 
-    @objc public func isLanguageSupported(_ language: String) -> Bool {
-        let languages = self.getSupportedLanguages()
-        return languages.contains(language)
+    @objc public func isLanguageSupported(_ lang: String) -> Bool {
+        let voice = AVSpeechSynthesisVoice(language: lang)
+        return voice != nil
     }
 
     // Adjust rate for a closer match to other platform.

ios/Plugin/TextToSpeechPlugin.m

@@ -9,4 +9,5 @@
            CAP_PLUGIN_METHOD(openInstall, CAPPluginReturnPromise);
            CAP_PLUGIN_METHOD(getSupportedLanguages, CAPPluginReturnPromise);
            CAP_PLUGIN_METHOD(getSupportedVoices, CAPPluginReturnPromise);
+           CAP_PLUGIN_METHOD(isLanguageSupported, CAPPluginReturnPromise);
 )

ios/Plugin/TextToSpeechPlugin.swift

@@ -53,4 +53,12 @@ public class TextToSpeechPlugin: CAPPlugin {
             "voices": []
         ])
     }
+
+    @objc func isLanguageSupported(_ call: CAPPluginCall) {
+        let lang = call.getString("lang") ?? ""
+        let isLanguageSupported = self.implementation.isLanguageSupported(lang)
+        call.resolve([
+            "supported": isLanguageSupported
+        ])
+    }
 }

src/definitions.ts

@@ -8,13 +8,19 @@ export interface TextToSpeechPlugin {
    */
   stop(): Promise<void>;
   /**
-   * Returns a list of supported languages.
+   * Returns a list of supported BCP 47 language tags.
    */
   getSupportedLanguages(): Promise<{ languages: string[] }>;
   /**
    * Returns a list of supported voices.
    */
   getSupportedVoices(): Promise<{ voices: SpeechSynthesisVoice[] }>;
+  /**
+   * Checks if a specific BCP 47 language tag is supported.
+   */
+  isLanguageSupported(options: {
+    lang: string;
+  }): Promise<{ supported: boolean }>;
   /**
    * Verifies proper installation and availability of resource files on the system.
    *

src/web.ts

@@ -52,6 +52,14 @@ export class TextToSpeechWeb extends WebPlugin implements TextToSpeechPlugin {
     return { voices };
   }
 
+  public async isLanguageSupported(options: {
+    lang: string;
+  }): Promise<{ supported: boolean }> {
+    const result = await this.getSupportedLanguages();
+    const isLanguageSupported = result.languages.includes(options.lang);
+    return { supported: isLanguageSupported };
+  }
+
   public async openInstall(): Promise<void> {
     this.throwUnimplementedError();
   }