Need to total up selections - google-apps-script

Question

I am new to Google scripting and am trying to create an order form that totals on a new sheet. I found some tutorials that have gotten me this far.
https://docs.google.com/spreadsheets/d/1gABaW1qaJyaL1k4QSh0nqkJ7uCCyc8NmL02wcn1klpA/edit?usp=sharing
The current script allows styles and color/size options to be populated on the Ranges sheet that then is auto-populated on the Order Form sheet based on their selection. Since the styles and color/size options can change I need a script to create the Order Totals sheet which will contain the totals for each Style, Color/Size option that is populated on the Order Form sheet.
With the sample data that I have in the Order form the Order Totals would look like:
Style, Color/Size, Quantity
=
Adult Unisex, Grey - Small, 3
-
Youth, Grey - Large, 1
-
Youth, Grey - X-Large, 3
-
Adult Unisex, Grey - Medium, 1
-

Answer 1

You can probably do this somehow with the Sheets built-in functions, but here is an Apps Script solution that is working for me on the sheet you provided.
This is a general solution for n columns of item descriptors before a final quantity column.
/**
* #param {string} A1RangeString - e.g. "A1:C"
* #returns {string[][]} suitable for Range.setValues
*/
function getOrderTotals(A1RangeString) {
var orders = SpreadsheetApp.getActive().getSheetByName("Order Form")
.getRange(A1RangeString).getValues().filter(function (row) {
return row[0]; // i.e. it's not blank
});
var totals = orders.reduce(readOrders, {});
return writeTotals(totals);
}
/**
* #param {obj} orderBook - nested dictionary, see readOrders
* #returns {string[][]} for use with Range.setValues
*/
function writeTotals(orderBook) {
if (typeof orderBook === "number") {
return [orderBook];
}
var items = [];
Object.keys(orderBook).forEach(function(key) {
var result = writeTotals(orderBook[key]);
result.forEach(function (description) {
items.push([key].concat(description));
});
});
return items;
}
/**
* readOrders is a callback for Array.prototype.reduce
* #param {obj} orderBook - a nested dictionary
* #param {row} string[]
*/
function readOrders(orderBook, row) {
var item = orderBook;
for (var i = 0; i < row.length - 2; ++i) {
if (! item[row[i]]) {
item[row[i]] = {};
}
item = item[row[i]];
}
if (! item[row[row.length - 2]]) {
item[row[row.length - 2]] = row[row.length - 1];
} else {
item[row[row.length - 2]] += row[row.length - 1];
}
return orderBook;
}
function onEdit() {
var orders = getOrderTotals("C3:E");
SpreadsheetApp.getActive().getSheetByName("Order Totals")
.getRange(1, 1, orders.length, orders[0].length)
.setValues(orders);
// other onEdit stuff continues below
}