GAS - Ranged Cells Protection - google-apps-script

Question

I noticed there is quite a number of questions here regarding protection on cells in a spreadsheet.
But there seems to be no viable solution.
For example, column 'A' can only be edited by person1#email.com, and column 'B' can only be edited by person2#email.com.
There seems to be an issue tracker on google site since 2013...but Google has not come up with an API for it yet.
Does anyone have a workaround?
The code below only works for entire page protection..
sheet.setSheetProtection(permissions);

Answer 1

Use an onEdit() function that checks what user is editing the Sheet, then check what column is being edited. Have an object of user names, and what columns they can edit. If a user is not allowed to edit, undo the change.
You can only undo the change if you have a way of knowing what the last cell value was. There is no undo method in Apps Script, or other built in way to get the old value with Apps Script. But there is a way to configure the data to achieve a way to undo the edit.
Have a central sheet with all formulas referring to other sheets. In other words, the data that people view is a copy of the stored data in another sheet. Divide the data into sheets according to who can edit what. The code will write data to the correct sheet when a cell is edited.
Basically, you would have sheets that are the database where the data is stored. Those sheets could even be hidden, and of course they would be protected.
The viewing and editing would be done in a separate sheet from the sheets that are the official data storage.
So, the sheet that people are viewing and editing is the "User Interface"; it's the "Front End" of the "App". The sheets that are the official data storage are the "Back End".
function onEdit(e){
Logger.log("e.value: " + e.value);
Logger.log("e.range.getRow: " + e.range.getRow());
Logger.log("e.range.getColumn: " + e.range.getColumn());
var objWhoCanEditWhat = {"user1":"[A,B]", "user2":"[A]"};
//Get this user
var thisUserIs = Session.getActiveUser().getEmail();
Logger.log('thisUserIs: ' + thisUserIs);
Logger.log('Index of #: ' + thisUserIs.indexOf("#"));
thisUserIs = thisUserIs.substring(0, thisUserIs.indexOf("#"));
Logger.log('thisUserIs: ' + thisUserIs);
var whatColumnCanEdit = objWhoCanEditWhat[thisUserIs];
Logger.log('whatColumnCanEdit: ' + whatColumnCanEdit);
var editedColumn = e.range.getColumn();
var editedRow = e.range.getRow();
Logger.log('editedColumn: ' + editedColumn)
var ss = SpreadsheetApp.getActiveSpreadsheet();
//There must be a way to determine what sheet needs to be accessed, and that sheet name
//is set dynamically.
var objColumnEditedToSheetName = {"ColA":"Sheet6TY", "ColB":"SheetColumnB"};
var whatSheetToUse = objColumnEditedToSheetName[editedColumn];
if (whatColumnCanEdit != editedColumn) { //If the column this user can edit is not the same as
//the column that just was edited, then
//Undo the change with this code
//Retrieve the old official data from the data storage sheet
var sheet = ss.getSheetByName(whatSheetToUse);
} else {
//If the user is allowed to edit this column, write the data to the official data storage sheet
var sheet = ss.getSheetByName(whatSheetToUse);
};
//Always put a formula back into the cell that was just edited in order
//to show data from the back end data source
var viewSheet = ss.getSheetByName("SheetForEditingAndViewing");
//You know the row and column of the cell that was just edited, so use that to
//reference what cell to put the formula back into.
viewSheet.getRange(editedRow, editedColumn).setFormula("Sheet1!A3");
};