Tuesday, 2 September 2014

Showing When An Appointment Slot is FULL using Google Forms and Apps Script

I'm sorry this isn't a finished solution you can just copy and paste. It's more of an example, sharing THAT this can easily be done which may help you figure out how to do it your case.

Lots of people at the University of York are using Google Forms to allow people to sign up to events. They use forms rather than Appointment Slots because they want to work with the data to generate registers for the people running the events.

But often these events have a capacity, that is, once 20 people have signed up to them, they're full.

There isn't much you can do with Google Forms to "live lookup" data and change form items if they're full, so we have developed workarounds to mimic this behaviour.

Firstly, having created our Form in the regular way, we create an extra sheet that keeps a track of how many people have have signed up, like this...

The count column has a formula in it like this...

=COUNTIF('Form responses 1'!G:G,B2)

...and the limit is a number we entered of how many places that slot has.

Secondly, we need to create a couple of functions that get fired when someone signs up to a session, like this...

function find_limits(rangeA1, their_choice){ //the values for the range and choice parsed in the main function
// the range is where you want to look in Group Totals var ss = SpreadsheetApp.getActiveSpreadsheet() var sheet = ss.getSheetByName("Group Totals") var range = sheet.getRange(rangeA1) var values = range.getValues() //get the count and limit values for the question's range for the user's choice for ( v in values){ var row = values[v] if (row[0] == their_choice){ return [row[1], row[2]] //the first value (row[0]) is their choice
// the second value (row[1]) is the count 
// the third value (row[2]) is the limit } } } function test_find_limits(){ Logger.log( find_limits("B3:E23", "11:45-12:00")) }


function check_availability(item_id, count, limit, their_choice){ var ss = SpreadsheetApp.getActiveSpreadsheet() var sheet = ss.getSheetByName("Group Totals") var form_id = "YOUR_FORM_ID_HERE" //the form ID is from the url. var form = FormApp.openById(form_id) var items = form.getItems() var item = form.getItemById(item_id).asListItem() var choices = item.getChoices() //pulls out the multiple choice question choices.  
//Can't pull out one particular choice so pulls them all out and iterates var choices_list = [ ] for (c in choices){ var choice = choices[c] if (choice.getValue() == their_choice){ if (count >= limit){ //It's up to the limit! choices_list.push(their_choice + " FULL!" ) 
}else{ choices_list.push(choices[c].getValue()) } }else{ choices_list.push(choices[c].getValue() ) } } item.setChoiceValues(choices_list) }

So, basically, when someone books an appointment, the script looks in the "Group Totals" sheet, and if the count is equal to the limited number of places, it changes the multiple choice items title to "10:00 - 10:30 FULL!".

What's interesting about this is that although you can't do live changes to the form, this script essentially changes the form items for the next person who uses it.

I did experiment with deleting the multiple choice item, but had a few funny results, so thought it best to just change its name. This can be a good idea anyway, to show to users that slots did exist but now they're gone.

Of course in this case someone can still book a full slot ( it doesn't prevent it) , but this process is, in our case, policed by a human anyway. This method is a way to heavily dissuade people from selecting full course slots.

Hope this helps.


  1. I do not think you explained it that well.

  2. Hello Frndz...
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