Google Apps Script本地化开发：如何获取完整的语言及国家代码

Great question—this is a common pain point when building localized Google Workspace add-ons, since Session.getActiveUserLocale() only returns a language code (like en) instead of the full language-region identifier (like en-US) that matches the user's actual Sheets display language settings.

Here are three actionable solutions to get the complete locale you need:

1. Retrieve Full Locale via the Drive API #

The Drive API's About resource returns a userLocale field that includes both language and region code (e.g., en-US, es-ES). This is the most reliable method because it pulls directly from the user's Google account settings.

To implement this:

• First, enable the Drive API in your Apps Script project: Go to Services > Add a service > Select Drive API > Click Add.
• Then use this function to fetch the full locale:

  function getFullUserLocale() {
    try {
      const driveAbout = Drive.About.get();
      return driveAbout.userLocale; // Returns format like "en-US"
    } catch (error) {
      // Handle authorization or API errors
      console.error("Failed to fetch locale:", error);
      return Session.getActiveUserLocale(); // Fallback to basic language code
    }
  }
  

  Note: Users will need to grant your add-on permission to access their Drive settings the first time this runs—make sure to explain this in your add-on's authorization prompt to avoid confusion.

2. Fallback to Session.getScriptLocale() (Context-Dependent) #

If your add-on is bound to a specific Google Sheet (not a standalone web app), Session.getScriptLocale() sometimes returns the full language-region locale of the document's owner. However, this is not guaranteed to match the current user's settings, so it should only be used as a fallback if the Drive API method isn't feasible.

Example:

function getLocaleFallback() {
  const userLocale = Session.getActiveUserLocale();
  if (userLocale.length === 2) {
    return Session.getScriptLocale(); // May return "en-US" instead of just "en"
  }
  return userLocale;
}

3. Prompt the User for Region (Last Resort) #

If the above methods don't work for your use case, you can build a simple UI prompt to ask users to select their region when you detect a 2-letter language code. Store their selection using PropertiesService so you don't have to ask every time.

Example flow:

• Check if Session.getActiveUserLocale() is a 2-letter code (e.g., en).
• If yes, show a dialog with region options (e.g., "English (US)", "English (UK)", "English (AU)").
• Save the selected full locale (e.g., en-US) to PropertiesService.getUserProperties().
• Use this saved value for all future localization.

Key Notes #

• The Drive API method is the most accurate, but requires additional authorization.
• Always include a fallback to Session.getActiveUserLocale() in case of API errors or permission denials.
• Test across different user settings to ensure your implementation works for locales like fr-CA, pt-BR, etc.

内容的提问来源于stack exchange，提问作者Putta