How to define global variable in Google Apps Script - google-apps-script

Question

I see most examples from Google is they use only functions in a single giant script.
e.g. https://developers.google.com/apps-script/quickstart/macros
But in our style, we usually write all functions under a single namespace, such as
MyCompany = (MyCompany || {});
MyCompany.init = function () {
Logger.log('init');
};
function onOpen() {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var menus = [{
name: "Init",
functionName: MyCompany.init
}];
spreadsheet.addMenu("Test", menus);
};
However, when I run the code above, it return
"MyCompany is not defined."
How to solve?

Answer 1

You might be better off using the Properties Service as you can use these as a kind of persistent global variable.
click 'file > project properties > project properties' to set a key value, or you can use
PropertiesService.getScriptProperties().setProperty('mykey', 'myvalue');
The data can be retrieved with
var myvalue = PropertiesService.getScriptProperties().getProperty('mykey');

Answer 2

In GAS global variables are not what they are in other languages. They are not constants nor variables available in all routines.
I thought I could use global variables for consistency amongst functions and efficiency as well. But I was wrong as pointed out by some people here at SO.
Global variable will be evaluated at each execution of a script, so not just once every time you run your application.
Global variables CAN be changed in a script (so they are not constants that cannot be changed by accident), but will be reinitialized when another script will be invoked.
There is also a speed penalty on using global variables. If within a function you use the same global variable two or more times, it will be faster to assign a local variable and use that instead.
If you want to preserve variables between all functions in your application, it might be using a cacheService will be best.
I found out that looping through all files and folders on a drive takes a LOT of time. But you can store info about files and folders within cache (or even properties) and speed up at least 100 times.
The only way I use global variables now is for some prefixes and for naming widgets.

Answer 3

I'm using a workaround by returning a function with an object of my global variables:
function globalVariables(){
var variables = {
sheetName: 'Sheet1',
variable1: 1,
variable2: 2
};
return variables;
}
function functionThatUsesVariable (){
var sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(globalVariables().sheetName);
}

Answer 4

Global variables certainly do exist in GAS, but you must understand the client/server relationship of the environment in order to use them correctly - please see this question:
Global variables in Google Script (spreadsheet)
However this is not the problem with your code; the documentation indicates that the function to be executed by the menu must be supplied to the method as a string, right now you are supplying the output of the function:
https://developers.google.com/apps-script/reference/spreadsheet/spreadsheet#addMenu%28String,Object%29
function MainMenu_Init() {
Logger.log('init');
};
function onOpen() {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var menus = [{
name: "Init",
functionName: "MainMenu_Init"
}];
spreadsheet.addMenu("Test", menus);
};

Answer 5

I needed something similar like the question, you can store and fetch from the cache https://developers.google.com/apps-script/reference/cache/cache
Example:
// call cache service
var cache = CacheService.getScriptCache();
// get an item from the cache
var cached = cache.get("somekey");
// if exists in the cache use it
if (cached != null) {
// use it whatever you like.
}else{
// calculate/assign your data to cache
cache.put("somekey","somevalueorobject");
// you can even put cache data on TTL (time to live) in seconds.
cache.put("somekey","somevalueorobject",60);

Answer 6

I use this: if you declare var x = 0; before the functions declarations, the variable works for all the code files, but the variable will be declare every time that you edit a cell in the spreadsheet

Answer 7

For constants I am using function arrow expressions.
The footprint is similar to a variable declaration. Just add the () => when declaring, and () when calling the (function) variable.
var currentSheet = () => SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
var maxAttempts = () => 10;
function myFunction(){
var sheetName = currentSheet().getName();
for (var i=0; i< maxAttempts(); i++){
trySomething(i);
}
}

Answer 8

var userProperties = PropertiesService.getUserProperties();
function globalSetting(){
//creating an array
userProperties.setProperty('gemployeeName',"Rajendra Barge");
userProperties.setProperty('gemployeeMobile',"9822082320");
userProperties.setProperty('gemployeeEmail'," rajbarge#hotmail.com");
userProperties.setProperty('gemployeeLastlogin',"03/10/2020");
}
var userProperties = PropertiesService.getUserProperties();
function showUserForm(){
var templete = HtmlService.createTemplateFromFile("userForm");
var html = templete.evaluate();
html.setTitle("Customer Data");
SpreadsheetApp.getUi().showSidebar(html);
}
function appendData(data){
globalSetting();
var ws = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Data");
ws.appendRow([data.date,
data.name,
data.Kindlyattention,
data.senderName,
data.customereMail,
userProperties.getProperty('gemployeeName'),
,
,
data.paymentTerms,
,
userProperties.getProperty('gemployeeMobile'),
userProperties.getProperty('gemployeeEmail'),
Utilities.formatDate(new Date(), "GMT+05:30", "dd-MM-yyyy HH:mm:ss")
]);
}
function errorMessage(){
Browser.msgBox("! All fields are mandetory");
}