Creating hash array in Google Apps Script

Question

I\'ve been trying to work with Trello and the Google Apps Script this week. I am trying to create an array of hashes that I can then use to load the spreadsheet. Google apps s

Answer 1

Summary: For onEdit() purposes, use Cache Service to define associative array data.

Here's a shared Gsheet demonstrating this curious behavior. I tried the following solution in programmatically defining an associative array based on data in a Google sheet.

var assocArr = {
  labels: {},
  init: function () {
    var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('sheetName');
    var values = sheet.getDataRange().getValues();
    for(var row in values) {
      assocArr.labels[values[row][0]] = values[row][1];
    };
    for(var key in assocArr.labels) {
      Logger.log("key: %s, value: %s",key, assocArr.labels[key]);
    };
    return(void(0));
  },
};

To execute this, you run the init() method in the onOpen() event handler.

function onOpen() {
  assocArr.init();
  var key = 'test';
  SpreadsheetApp.getUi().alert( assocArr.labels[key] );
  Logger.log("onOpen: key: %s, value: %s",key, assocArr.labels[key]);
};

The logger message confirms that init() loads the data from the worksheet.

Now if I try to reference this assocArr object in onEdit() it returns undefined for all key values.

function onEdit(event) {
  var key = 'test';
  SpreadsheetApp.getUi().alert( assocArr.labels[key] );
  Logger.log("onEdit: key: %s, value: %s",key, assocArr.labels[key]);
};

I infer that for security reasons, Google limited the simple-trigger onEdit() to not have global variable scope, same as they voided the utility of the event.user property.

Now instead if I simply put the key-value pair in the cache, it works! Here is the complete code that works using the Cache Service.

var cache = CacheService.getPrivateCache();

var assocArr = {
  init: function () {
    var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Account Labels');
    var values = sheet.getDataRange().getValues();
    for(var row in values) {
      cache.put(values[row][0], values[row][1], 3600);
    };
    return(void(0));
  },
};

function onOpen() {
  assocArr.init();
  var key = 'test';
  SpreadsheetApp.getUi().alert( cache.get(key) );
  Logger.log("onOpen: key: %s, value: %s",key, cache.get(key));
};


function onEdit(event) {
  var key = 'test';
  SpreadsheetApp.getUi().alert( cache.get(key) );
  Logger.log("onEdit: key: %s, value: %s",key, cache.get(key));
};

Curiously, the onEdit() has the cache variable in its scope.

Here again is the shared Gsheet demonstrating this curious behavior.