Wednesday, February 13, 2013

[Gd] Crowdsourcing Localization with Google Apps Script

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Google Apps Developer Blog: Crowdsourcing Localization with Google Apps Script

Editor’s Note: Guest author John Gale is a Solutions Developer at Appogee, a Google Cloud Service Partner. — Arun Nagarajan

Ever since we launched Appogee Leave — the first tool in the Google Apps Marketplace for tracking employees’ absences and time off — customers have been asking, “Can you support my native language?”

Our partners offered to help crowdsource the translation, but it was a challenge to know where to begin. We started by identifying a few needs:

  • Users must be able to provide new translations
  • Users must be able to flag bad translations and recommend changes
  • Developers must be able to integrate completed translations
  • Customer service must be able to keep users informed of progress

With just a couple days’ effort in Google Apps Script, we created a complete application for crowd-sourced localization that handles each of those requirements. You can get a glimpse of the system in the screenshot below.

Source: Appogee

Let’s take a look at a few specific Apps Script tricks we used to make the whole thing work.

Avoid Collisions with Lock Service

Like many Apps Script users, we store almost all of the data for our translation system in Google Sheets, including both the list of English terms we want to translate and users’ translations.

During testing, we found that if two users submitted translations at the same time, the spreadsheet wrote both sets of changes to the same place, causing us to lose one user’s updates. To solve this, we use Apps Script’s semaphore-based Lock Service. In the code below, a public lock ensures that a user has temporary exclusive use of the spreadsheet so that their correction is added even if another user also submits a correction.

function submit(e){
/* get the fields from the UI callback */
var incorrect = e.parameter.foreignWordIncorrectTxt;
var correct = e.parameter.foreignWordCorrectTxt;
var reason = e.parameter.reasonTxt;
var lang = e.parameter.hiddenLang;

/* validate the input; return the user a message if invalid */

/* open the spreadsheet */
var active_user_email = UserProperties.getProperty('user_email') || "";
var master_spreadsheet = SpreadsheetApp.openById(MASTER_SPREADSHEET_KEY);
var correction_sheet = master_spreadsheet.getSheetByName('Corrections');

/* get a lock and update the spreadsheet */
var lock = LockService.getPublicLock();
lang, incorrect, correct, reason, active_user_email

/* reset the UI */
return reset();

You’ll note that this code opens the spreadsheet before obtaining a lock. At this point, we are only reading, not writing, and thus do not yet require a lock. We then tell Apps Script we are prepared to wait up to 30 seconds for our turn to lock the worksheet. On the rare occasion that a lock is not available within 30 seconds (usually because somebody else has an exclusive lock), the code throws an exception and stops execution.

Once we have acquired the lock, we quickly write the correction to the spreadsheet — including a call to SpreadsheetApp.flush() to ensure the data is written immediately — and release the lock.

Save Time with Cache Service

Because the translations are stored in a spreadsheet along with information about who provided them, it’s easy to recognize our top contributors through a leaderboard. The leaderboard data is a good candidate for caching because it’s shown to a large number of people, but only changes when we receive new updates from top-ranking users.

Like the Lock Service described earlier, the Cache Service provides both public and private variants. The public cache is useful for storing data that should be available to all users, such as the leaderboard. The private cache is more appropriate for storing information about a user, such as the translations they have submitted so far.

Since the Apps Script cache can only store strings, complex objects must first be converted. Lucky for us, Apps Script provides JSON utilities that make this conversion easy, as shown in this example:

function getBoardData(){
var cache = CacheService.getPublicCache();
var leaderboard_data = cache.get('leaderboard_data');
if (leaderboard_data == null) {
leaderboard_data = getTopTen();
} else {
leaderboard_data = Utilities.jsonParse(leaderboard_data);
return leaderboard_data;

Our hope is that the leaderboard will encourage users to provide more translations by introducing some friendly competition.

Thanks to Google Apps Script and the techniques shown above, we built a powerful crowdsourcing translation system without unnecessary complexity or development effort. If you’d like to help translate Appogee Leave, we’d love to have your contribution.

Source: Appogee

John Gale   profile | twitter

John Gale is a Solutions Developer at Appogee, a Google Cloud Service Partner. John develops software that helps customers make the most of the Google Cloud platform. He has worked on a range of cloud-based applications including Google Apps Marketplace applications, client projects involving Lotus Notes application migration, and mobile data-capture applications.


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