当自动更新的单元格更改值时，如何让 Google 表格向您发送电子邮件

Question

I'm very new to scripting in Google Sheets so my question may be either a lot more difficult than I think, or much simpler.

Basically, I have a Google Sheet that keeps track of a list of birthdays in one column, as well as what age group that person would belong to -- Child (under 13), Teen (13-17), or Adult (18+) -- in another column. The "Age Group" column is calculated using the following formula:

=IF(DATEDIF(H2, TODAY(), "Y") >= 18, "Adult", IF(DATEDIF(H2, Today(), "Y") >= 13, "Teen", "Child"))

with column H being the Birthday column.

My Google Sheet is set to recalculate the Today() function every hour, regardless of whether the file is open or not, so should a person's 13th or 18th birthday roll around, the Age Group column will update automatically.

My goal is to create a function that sends me an email whenever somebody's Age Group changes from Child to Teen or from Teen to Adult -- without requiring the Google Sheet to be opened by the user, or modified in any way, to trigger.

So far, I've been experimenting with "on edit" triggers, but I've noticed that this requires me to manually change an Age Group cell to trigger -- defeating the purpose of automation.

I've also tried changing my Trigger Event Type from "on edit" to "on change", hoping this would trigger the script whenever a cell in the Age Group column changes its resulting value, but this has not worked so far.

My code currently stands as follows (note that this code only makes a notice pop up rather than sending an actual email -- I haven't yet gotten to that part):

/*
This is the function that is triggered by an edit to
the Google Sheet
*/
function onEdit(e) {
  sendEmailOnApproval(e);  
}

/*
Primarily used for earlier debugging
*/
function showMessageOnApproval(e)
{
  var edited_row = checkStatusIsApproved(e);
  if(edited_row > 0)
  {
    SpreadsheetApp.getUi().alert("Row # "+edited_row+" approved!");
  }
}

/*
Determines if the Age Group column reads Teen or Adult.
Column 9 (or 'I' in the sheet) is the Age Group column.
*/
function checkStatusIsApproved(e)
{
  var range = e.range;

  if(range.getColumn() <= 9 && 
     range.getLastColumn() >=9 )
  {
    var edited_row = range.getRow();

    var status = SpreadsheetApp.getActiveSheet().getRange(edited_row,9).getValue();
    if(status == 'Adult' || status == 'Teen')
    {
      return edited_row;
    }
  }
  return 0;
}

function sendEmailOnApproval(e)
{
  var approved_row = checkStatusIsApproved(e);

  if(approved_row <= 0)
  {
    return;
  }

  sendEmailByRow(approved_row);
}


/*
At the moment, this function only creates a little pop-up
box containing the text of the email I would like to send.
*/
function sendEmailByRow(row)
{
  var values = SpreadsheetApp.getActiveSheet().getRange(row,1,row,9).getValues();
  var row_values = values[0];

  var mail = composeApprovedEmail(row_values);

  SpreadsheetApp.getUi().alert(" subject is "+mail.subject+"\n message "+mail.message);
}


/*
Writes the email. Column 0 (or 'A') is the first name,
1 (or 'B') is the last name.
*/
function composeApprovedEmail(row_values)
{
  var first_name = row_values[0];

  var last_name = row_values[1];

  var age = row_values[8];

  var message = "The following person should be updated on the website: "+first_name+" "+last_name+
    " Age Range: "+age;
  var subject = "UPDATE WEBSITE for "+first_name+" "+last_name;

  return({message:message,subject:subject});
}

While this code works when manually changing the values in the Age Range column, how can I adapt it to catch the automatic updates caused by daily recalculation of the Today() function the column relies on?

Answer 1

According to the Apps Script Trigger documentation :

• onOpen(e) runs when a user opens a spreadsheet, document, presentation, or form that the user has permission to edit

• onEdit(e) runs when a user changes a value in a spreadsheet

Therefore, what you are trying to do cannot be done by using the method that you were previously using since you were trying to use a trigger which would fire every time a change was made by a function (the Sheets formula) and not by a user.

Workaround

What you can do instead is to:

1. Use the Sheets formula you were previously using but change the Recalculation settings to On change instead of On change and every hour like you were previously doing.

In this way, you will still get the ages categorized based on the dates provided.

2. Use the following script:

function ageChanges(){
  var ss = SpreadsheetApp.getActive().getActiveSheet();
  var dateVals = ss.getRange("YOUR_RANGE_FOR_THE_DATES").getValues();
  var ageVals = ss.getRange("YOUR_RANGE_FOR_THE_AGES").getValues();
  var dateNow = new Date();
  var recipient = "EMAIL_ADDRESS";
  var subject = "Age Change in Spreadsheet";
  var body = "";

  for (var i=0; i<dateVals.length; i++){
    
    var ages = (dateNow - dateVals[i][0])/(3.154e+10);

    if (ages > 18 && ageVals[i][0]!="Adult") {
      ss.getRange(i+1, 9).setValue("Adult");
      body = "Change in column H, row"+i+".";
      MailApp.sendEmail(recipient,subject,body);
      
    }
    else if (ages > 13 && ages < 18 && ageVals[i][0]!="Teen") {
      ss.getRange(i+1, 9).setValue("Teen");
      body = "Change in column H, row"+i+".";
      MailApp.sendEmail(recipient,subject,body);
    }
      
  }
     
}

The script computes the ages based on the dates you have in your Spreadsheet. If the age does not match with the corresponding category, a mail will be sent with the changes made.

In order to monitor the changes daily you will have to use the above script as an installable trigger .

3. Create an installable trigger with the following options:

In this way, the script will run every day at the time of the day selected by you (in this case, Midnight to 1am ) and if any age changes occur, you will receive the email(s) with the changes.

Furthermore, I suggest you take a look at these links since they might be of help in your future development:

• Installable Triggers ;

• MailApp Class .