Skip to content

Commit

Permalink
Let the browser detect language per text selection
Browse files Browse the repository at this point in the history
  • Loading branch information
@joelpurra
joelpurra committed Dec 31, 2016
1 parent a373826 commit 5d9d1c3
Showing 1 changed file with 161 additions and 69 deletions.
230 changes: 161 additions & 69 deletions src/background.js
View file
Expand Up @@ -252,103 +252,195 @@ const detectPageLanguage = () => new Promise(
}
);

const cleanupSelections = (allVoices, detectedPageLanguage, selections) => {
const isNonNullObject = (selection) => !!selection && typeof selection === "object";
const detectTextLanguage = (text) => new Promise(
(resolve, reject) => {
try {
if (!("detectLanguage" in chrome.i18n)) {
// NOTE: text-based language detection is only used as a fallback.
log("detectTextLanguage", "Browser does not support detecting text language");

const hasValidText = (selection) => !isUndefinedOrNullOrEmptyOrWhitespace(selection.text);
return resolve(null);
}

const isValidString = (str) => !isUndefinedOrNullOrEmptyOrWhitespace(str);
chrome.i18n.detectLanguage(text, (result) => {
// https://developer.chrome.com/extensions/i18n#method-detectLanguage
if (chrome.runtime.lastError) {
return reject(chrome.runtime.lastError);
}

const trimText = (selection) => {
var copy = shallowCopy(selection);
// The language fallback value is "und", so treat it as no language.
if (!result.isReliable && result.languages.length > 0 && result.languages[0].language !== "und") {
// NOTE: text-based language detection is only used as a fallback.
log("detectTextLanguage", "Browser did not detect reliable text language", result);

copy.text = copy.text.trim();
return resolve(null);
}

return copy;
};
const primaryDetectedTextLanguage = result.languages[0].language;

const isKnownVoiceLanguage = (elementLanguage) => allVoices.some((voice) => voice.lang.startsWith(elementLanguage));

// https://www.iso.org/obp/ui/#iso:std:iso:639:-1:ed-1:v1:en
// https://en.wikipedia.org/wiki/ISO_639-1
// https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
// http://xml.coverpages.org/iso639a.html
// NOTE: discovered because Twitter seems to still use "iw".
const iso639Dash1Aliases1988To2002 = {
"in": "id",
"iw": "he",
"ji": "yi",
};
log("detectTextLanguage", "Browser detected reliable text language", result, primaryDetectedTextLanguage);

const mapIso639Aliases = (language) => {
return iso639Dash1Aliases1988To2002[language] || language;
};
return resolve(primaryDetectedTextLanguage);
});
} catch(error) {
return reject(error);
}
}
);

const cleanupParentElementsLanguages = (selection) => {
var copy = shallowCopy(selection);
const cleanupSelections = (allVoices, detectedPageLanguage, selections) => promiseTry(
() => {
const isNonNullObject = (selection) => !!selection && typeof selection === "object";

copy.parentElementsLanguages = copy.parentElementsLanguages || [];
copy.parentElementsLanguages = copy.parentElementsLanguages
.filter(isValidString)
.map(mapIso639Aliases)
.filter(isKnownVoiceLanguage);
const hasValidText = (selection) => !isUndefinedOrNullOrEmptyOrWhitespace(selection.text);

return copy;
};
const trimText = (selection) => {
var copy = shallowCopy(selection);

const setEffectiveLanguage = (selection) => {
var copy = shallowCopy(selection);
copy.text = copy.text.trim();

copy.effectiveLanguage = copy.parentElementsLanguages[0] || copy.htmlTagLanguage || detectedPageLanguage || null;
return copy;
};

return copy;
};
const selectionsWithValidText = selections
.filter(isNonNullObject)
.filter(hasValidText)
.map(trimText)
.filter(hasValidText);

const mapResults = (selection) => {
return {
text: selection.text,
effectiveLanguage: selection.effectiveLanguage,
return selectionsWithValidText;
})
.then((selectionsWithValidText) => Promise.all(
selectionsWithValidText.map(
(selection) => {
var copy = shallowCopy(selection);

return detectTextLanguage(copy.text)
.then((detectedTextLanguage) => {
copy.detectedTextLanguage = detectedTextLanguage;

return copy;
});
})
)
)
.then((selectionsWithValidTextAndDetectedLanguage) => {
const isKnownVoiceLanguage = (elementLanguage) => allVoices.some((voice) => voice.lang.startsWith(elementLanguage));

// https://www.iso.org/obp/ui/#iso:std:iso:639:-1:ed-1:v1:en
// https://en.wikipedia.org/wiki/ISO_639-1
// https://en.wikipedia.org/wiki/List_of_ISO_639-1_codes
// http://xml.coverpages.org/iso639a.html
// NOTE: discovered because Twitter seems to still use "iw".
const iso639Dash1Aliases1988To2002 = {
"in": "id",
"iw": "he",
"ji": "yi",
};
};

const cleanedupSelections = selections
.filter(isNonNullObject)
.filter(hasValidText)
.map(trimText)
.filter(hasValidText)
.map(cleanupParentElementsLanguages)
.map(setEffectiveLanguage)
.map(mapResults);
const mapIso639Aliases = (language) => {
return iso639Dash1Aliases1988To2002[language] || language;
};

if (cleanedupSelections.length === 0) {
log("Empty filtered selections");
const isValidString = (str) => !isUndefinedOrNullOrEmptyOrWhitespace(str);

cleanedupSelections.push(noTextSelectedMessage);
}
const cleanupLanguagesArray = (languages) => {
const copy = (languages || [])
.filter(isValidString)
.map(mapIso639Aliases)
.filter(isKnownVoiceLanguage);

return cleanedupSelections;
};
return copy;
};

const cleanupParentElementsLanguages = (selection) => {
var copy = shallowCopy(selection);

copy.parentElementsLanguages = cleanupLanguagesArray(copy.parentElementsLanguages);

const speakAllSelections = (synthesizer, selections, detectedPageLanguage) => {
return copy;
};

const getMoreSpecificLanguagesWithPrefix = (prefix) => {
return (language) => language.startsWith(prefix) && language.length > prefix.length;
};

const setEffectiveLanguage = (selection) => {
var copy = shallowCopy(selection);

var detectedLanguages = [
copy.detectedTextLanguage,
copy.parentElementsLanguages[0] || null,
copy.htmlTagLanguage,
detectedPageLanguage,
];

log("setEffectiveLanguage", "detectedLanguages", detectedLanguages);

var cleanedLanguages = cleanupLanguagesArray(detectedLanguages);

log("setEffectiveLanguage", "cleanedLanguages", cleanedLanguages);

const primaryLanguagePrefix = cleanedLanguages[0] || null;

log("setEffectiveLanguage", "primaryLanguagePrefix", primaryLanguagePrefix);

// NOTE: if there is a more specific language with the same prefix among the detected languages, prefer it.
const cleanedLanguagesWithPrimaryPrefix = cleanedLanguages.filter(getMoreSpecificLanguagesWithPrefix(primaryLanguagePrefix));

log("setEffectiveLanguage", "cleanedLanguagesWithPrimaryPrefix", cleanedLanguagesWithPrimaryPrefix);

const effectiveLanguage = cleanedLanguagesWithPrimaryPrefix[0] || cleanedLanguages[0] || null;

log("setEffectiveLanguage", "effectiveLanguage", effectiveLanguage);

copy.effectiveLanguage = effectiveLanguage;

return copy;
};

const mapResults = (selection) => {
return {
text: selection.text,
effectiveLanguage: selection.effectiveLanguage,
};
};

const selectionsWithValidTextAndDetectedLanguageAndEffectiveLanguage = selectionsWithValidTextAndDetectedLanguage.map(cleanupParentElementsLanguages)
.map(setEffectiveLanguage)
.map(mapResults);

if (selectionsWithValidTextAndDetectedLanguageAndEffectiveLanguage.length === 0) {
log("Empty filtered selections");

selectionsWithValidTextAndDetectedLanguageAndEffectiveLanguage.push(noTextSelectedMessage);
}

return selectionsWithValidTextAndDetectedLanguageAndEffectiveLanguage;
}
);

const speakAllSelections = (synthesizer, selections, detectedPageLanguage) => promiseTry(() => {
log("Start", "Speaking all selections");

log("Variable", `selections (length ${selections && selections.length || 0})`, selections);

const allVoices = synthesizer.getVoices();
const cleanedupSelections = cleanupSelections(allVoices, detectedPageLanguage, selections);

log("Variable", `cleanedupSelections (length ${cleanedupSelections && cleanedupSelections.length || 0})`, cleanedupSelections);
return promiseTry(() => synthesizer.getVoices())
.then((allVoices) => cleanupSelections(allVoices, detectedPageLanguage, selections))
.then((cleanedupSelections) => {
log("Variable", `cleanedupSelections (length ${cleanedupSelections && cleanedupSelections.length || 0})`, cleanedupSelections);

const speakPromises = cleanedupSelections.map((selection) => {
log("Text", `Speaking selection (length ${selection.text.length}, effectiveLanguage ${selection.effectiveLanguage})`, selection);
const speakPromises = cleanedupSelections.map((selection) => {
log("Text", `Speaking selection (length ${selection.text.length}, effectiveLanguage ${selection.effectiveLanguage})`, selection);

return speak(synthesizer, selection.text, selection.effectiveLanguage);
});
return speak(synthesizer, selection.text, selection.effectiveLanguage);
});

log("Done", "Speaking all selections");
log("Done", "Speaking all selections");

return Promise.all(speakPromises);
};
return Promise.all(speakPromises);
});
});

const speakUserSelection = (synthesizer) => promiseTry(() => {
log("Start", "Speaking selection");
Expand Down

0 comments on commit 5d9d1c3

Please sign in to comment.