Google Apps Script - Spreadsheet run script onEdit? - google-apps-script

Question

I have a script that I use in my spreadsheet. It is at cell B2 and it takes an argument like so =myfunction(A2:A12). Internally the function gets info from a large range of cells.
Nothing seems to work. I tried adding it to
Scripts > Resources > Current Project Triggers > On edit
Scripts > Resources > Current Project Triggers > On open
How can I have this function update the result with every document edit?

Answer 1

When you are making calls to Google Apps services inside your custom function (like getRange and getValues etc), unfortunately there is no way of updating such custom functions with each edit, other than passing all of the cells that you are "watching" for editing.
And, perhaps even more frustratingly, the workaround of passing say a single cell that references all of your "watched" cells with a formula doesn't trigger an update - it seems that one needs to reference the "watched" cells directly.
You could pass GoogleClock() as an argument which will at least update the function output every minute.
But the advice from many members on this forum (who have much more knowledge about this stuff than me) would simply be: "don't use custom functions".

Answer 2

I am not sure if this exact code will work but you can try something like this...
function onEdit(event){
var activeSheet = event.source.getActiveSheet();
if(activeSheet.getName() == "ActiveSheetName") {
var targetSheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("TargetSheetName");
targetSheet.getRange(2,2).setValue("=myfunction(A2:A12)");
}
}
Assuming that B2 cell in on the sheet "TargetSheetName" and assuming that the edited cell is on the sheet "ActiveSheetName", the function onEdit will trigger when you edited any cell in any sheet. Since there is an if statement to check if that edited cell is on the sheet "ActiveSheetName" it will trigger only if the edited cell is on that sheet and it will set the B" cell to the value =myfunction(A2:A12), forcing it to update (i guess).
hope that i am correct and that i was helpful

Answer 3

I had a similar issue, for me I wanted to "watch" one particular cell to trigger my function.
I did the following (pretending A1 is the cell i am watching)
IF(LEN(A1) < 1, " ", customFunction() )
This successfully triggered if I ever edited that cell. However:
"Custom functions return values, but they cannot set values outside
the cells they are in. In most circumstances, a custom function in
cell A1 cannot modify cell A5. However, if a custom function returns a
double array, the results overflow the cell containing the function
and fill the cells below and to the right of the cell containing the
custom function. You can test this with a custom function containing
return [[1,2],[3,4]];."
from: https://developers.google.com/apps-script/execution_custom_functions
which makes it almost useless, but it might work for your case?
If the custom function is assigned to a project trigger it has more power so personally I ended adding it to "Scripts > Resources > Current Project Triggers > On edit"
and basically "watched a column" so it only did things if the current cell was within the "edit range". This is a bit of a bodge and requires some hidden cells, but it works for me at the moment
var rowIndex = thisspreadsheet.getActiveCell().getRowIndex();
var colIndex = thisspreadsheet.getActiveCell().getColumn();
//clamp to custom range
if(rowIndex < 3 && colIndex != 5)
{
return 0;
}
//check against copy
var name = SpreadsheetApp.getActiveSheet().getRange(rowIndex, 5).getValue();
var copy = SpreadsheetApp.getActiveSheet().getRange(rowIndex, 6).getValue();
if(name != copy )
{
///value has been changed, do stuff
SpreadsheetApp.getActiveSheet().getRange(rowIndex, 6).setValue(name);
}