/**
* @OnlyCurrentDoc
*
* The above comment directs Apps Script to limit the scope of file
* access for this add-on. It specifies that this add-on will only
* attempt to read or modify the files in which the add-on is used,
* and not all of the user's files. The authorization request message
* presented to users will reflect this limited scope.
*/
/**
* Creates a menu entry in the Google Docs UI when the document is opened.
* This method is only used by the regular add-on, and is never called by
* the mobile add-on version.
*
* @param {object} e The event parameter for a simple onOpen trigger. To
* determine which authorization mode (ScriptApp.AuthMode) the trigger is
* running in, inspect e.authMode.
*/
function onOpen(e) {
DocumentApp.getUi().createAddonMenu()
.addItem('Start', 'showSidebar')
.addToUi();
}
/**
* Runs when the add-on is installed.
* This method is only used by the regular add-on, and is never called by
* the mobile add-on version.
*
* @param {object} e The event parameter for a simple onInstall trigger. To
* determine which authorization mode (ScriptApp.AuthMode) the trigger is
* running in, inspect e.authMode. (In practice, onInstall triggers always
* run in AuthMode.FULL, but onOpen triggers may be AuthMode.LIMITED or
* AuthMode.NONE.)
*/
function onInstall(e) {
onOpen(e);
}
/**
* Opens a sidebar in the document containing the add-on's user interface.
* This method is only used by the regular add-on, and is never called by
* the mobile add-on version.
*/
function showSidebar() {
const ui = HtmlService.createHtmlOutputFromFile('sidebar')
.setTitle('Translate');
DocumentApp.getUi().showSidebar(ui);
}
/**
* Gets the text the user has selected. If there is no selection,
* this function displays an error message.
*
* @return {Array.<string>} The selected text.
*/
function getSelectedText() {
const selection = DocumentApp.getActiveDocument().getSelection();
const text = [];
if (selection) {
const elements = selection.getSelectedElements();
for (let i = 0; i < elements.length; ++i) {
if (elements[i].isPartial()) {
const element = elements[i].getElement().asText();
const startIndex = elements[i].getStartOffset();
const endIndex = elements[i].getEndOffsetInclusive();
text.push(element.getText().substring(startIndex, endIndex + 1));
} else {
const element = elements[i].getElement();
// Only translate elements that can be edited as text; skip images and
// other non-text elements.
if (element.editAsText) {
const elementText = element.asText().getText();
// This check is necessary to exclude images, which return a blank
// text element.
if (elementText) {
text.push(elementText);
}
}
}
}
}
if (!text.length) throw new Error('Please select some text.');
return text;
}
/**
* Gets the stored user preferences for the origin and destination languages,
* if they exist.
* This method is only used by the regular add-on, and is never called by
* the mobile add-on version.
*
* @return {Object} The user's origin and destination language preferences, if
* they exist.
*/
function getPreferences() {
const userProperties = PropertiesService.getUserProperties();
return {
originLang: userProperties.getProperty('originLang'),
destLang: userProperties.getProperty('destLang')
};
}
/**
* Gets the user-selected text and translates it from the origin language to the
* destination language. The languages are notated by their two-letter short
* form. For example, English is 'en', and Spanish is 'es'. The origin language
* may be specified as an empty string to indicate that Google Translate should
* auto-detect the language.
*
* @param {string} origin The two-letter short form for the origin language.
* @param {string} dest The two-letter short form for the destination language.
* @param {boolean} savePrefs Whether to save the origin and destination
* language preferences.
* @return {Object} Object containing the original text and the result of the
* translation.
*/
function getTextAndTranslation(origin, dest, savePrefs) {
if (savePrefs) {
PropertiesService.getUserProperties()
.setProperty('originLang', origin)
.setProperty('destLang', dest);
}
const text = getSelectedText().join('\n');
return {
text: text,
translation: translateText(text, origin, dest)
};
}
/**
* Replaces the text of the current selection with the provided text, or
* inserts text at the current cursor location. (There will always be either
* a selection or a cursor.) If multiple elements are selected, only inserts the
* translated text in the first element that can contain text and removes the
* other elements.
*
* @param {string} newText The text with which to replace the current selection.
*/
function insertText(newText) {
const selection = DocumentApp.getActiveDocument().getSelection();
if (selection) {
let replaced = false;
const elements = selection.getSelectedElements();
if (elements.length === 1 && elements[0].getElement().getType() ===
DocumentApp.ElementType.INLINE_IMAGE) {
throw new Error('Can\'t insert text into an image.');
}
for (let i = 0; i < elements.length; ++i) {
if (elements[i].isPartial()) {
const element = elements[i].getElement().asText();
const startIndex = elements[i].getStartOffset();
const endIndex = elements[i].getEndOffsetInclusive();
element.deleteText(startIndex, endIndex);
if (!replaced) {
element.insertText(startIndex, newText);
replaced = true;
} else {
// This block handles a selection that ends with a partial element. We
// want to copy this partial text to the previous element so we don't
// have a line-break before the last partial.
const parent = element.getParent();
const remainingText = element.getText().substring(endIndex + 1);
parent.getPreviousSibling().asText().appendText(remainingText);
// We cannot remove the last paragraph of a doc. If this is the case,
// just remove the text within the last paragraph instead.
if (parent.getNextSibling()) {
parent.removeFromParent();
} else {
element.removeFromParent();
}
}
} else {
const element = elements[i].getElement();
if (!replaced && element.editAsText) {
// Only translate elements that can be edited as text, removing other
// elements.
element.clear();
element.asText().setText(newText);
replaced = true;
} else {
// We cannot remove the last paragraph of a doc. If this is the case,
// just clear the element.
if (element.getNextSibling()) {
element.removeFromParent();
} else {
element.clear();
}
}
}
}
} else {
const cursor = DocumentApp.getActiveDocument().getCursor();
const surroundingText = cursor.getSurroundingText().getText();
const surroundingTextOffset = cursor.getSurroundingTextOffset();
// If the cursor follows or preceds a non-space character, insert a space
// between the character and the translation. Otherwise, just insert the
// translation.
if (surroundingTextOffset > 0) {
if (surroundingText.charAt(surroundingTextOffset - 1) !== ' ') {
newText = ' ' + newText;
}
}
if (surroundingTextOffset < surroundingText.length) {
if (surroundingText.charAt(surroundingTextOffset) !== ' ') {
newText += ' ';
}
}
cursor.insertText(newText);
}
}
/**
* Given text, translate it from the origin language to the destination
* language. The languages are notated by their two-letter short form. For
* example, English is 'en', and Spanish is 'es'. The origin language may be
* specified as an empty string to indicate that Google Translate should
* auto-detect the language.
*
* @param {string} text text to translate.
* @param {string} origin The two-letter short form for the origin language.
* @param {string} dest The two-letter short form for the destination language.
* @return {string} The result of the translation, or the original text if
* origin and dest languages are the same.
*/
function translateText(text, origin, dest) {
if (origin === dest) return text;
return LanguageApp.translate(text, origin, dest);
}