feat: add error message in case of missing TTS voice for the selected language

aip_trainer/lambdas/js.py

@@ -27,6 +27,7 @@ function playAudio(text, language) {
     let voice_idx = 0;
     let voice_synth = null;
     let synth = window.speechSynthesis;
+    let voice_lang;
 
     function setSpeech() {
         return new Promise(
@@ -43,17 +44,33 @@ function playAudio(text, language) {
         )
     }
 
+    switch (language) {
+        case 'de':
+            voice_lang = 'de-DE';
+            break;
+        case 'en':
+            voice_lang = 'en-US';
+            break;
+        default:
+            console.log(`Sorry, we are out of ${expr}.`);
+            throw new Error(`Language ${language} not valid!`)
+            alert(`Language ${language} not valid!`)
+    }
+    
     let s = setSpeech();
     s.then((voices) => {
-        for (idx = 0; idx < voices.length; idx++) {
-            if (voices[idx].lang.slice(0, 2) == language) {
-                voice_synth = voices[idx];
-                break;
-            }
+        let voicesSynth = voices.filter(voice => voice.lang === voice_lang);
+        if (voicesSynth.length === 0) {
+            console.error(`No voice found for language ${voice_lang}, retry for less restrictive check (startsWith)...`)
+            voicesSynth = voices.filter(voice => voice.lang.startsWith(language));
+        }
+        if (voicesSynth.length === 0) {
+            console.error(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
+            throw new Error(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
+            alert(`No voice found for language ${voice_lang}/${language}, you should use the Text-To-Speech backend feature...`)
         }
-
         var utterThis = new SpeechSynthesisUtterance(text);
-        utterThis.voice = voice_synth;
+        utterThis.voice = voicesSynth[0];
         utterThis.rate = 0.7;
 
         synth.speak(utterThis);
@@ -62,3 +79,4 @@ function playAudio(text, language) {
     });
 }
 """
+1