Calculation of age for display logic

Forum|Forum|2 years ago
February 18, 2023
3 replies
341 views

+3

kerem
Level 1 ●

I'm working on a survey where I ask parents for their baby's birthdate and then want to display different questions based on their baby's age in months. I read many threads regarding this issue but still didn't manage to make this thing work.
Here is what I've done so far:
1. create this survey flow with an empty 'age' embedded data at the beginning of the survey:
2. Add these scripts to the header of the survey:

3. Add this code to the DOB question to create a Flatpick question that supposes to calculate the age in months and then insert it into the embedded data:
jQuery("#"+this.questionId+" .InputText").flatpickr({enableTime: false, altInput: true, altFormat: "d/m/Y ", dateFormat: "d/m/Y ", time_24hr: false});

var age = moment().diff(moment(jQuery("#"+this.questionId+" .InputText").val()), 'months');
Qualtrics.SurveyEngine.setEmbeddedData('age', age);
4. Add display logic to the last question.
But from what I see, the code just doesn't work. The embedded data stays empty no matter what I enter to the DOB question.
You can see this demo survey live here:
https://bgu.qualtrics.com/jfe/form/SV_3fs4Rf5i60XkNg2
What am I missing?
Thank you

+27

TomG
Level 8 ●●●●●●●●
Forum|Forum|2 years ago
February 19, 2023

Two issues:

Your age calculation needs to be in the addOnPageSubmit() function

You need to have moment parse the correct input date format

You should really use the Moment replacement Luxon.

Like

K

+3

kerem
Author
Level 1 ●
Forum|Forum|2 years ago
February 19, 2023

Thank you Tom,
Using your advice (and after spending some time with chat GTP), I managed to make it work. This is the final code for other people who struggle with JavaScript:
/*for the flatpickr field*/
Qualtrics.SurveyEngine.addOnload(function()
{
jQuery("#"+this.questionId+" .InputText").flatpickr({enableTime: false, altInput: true, altFormat: "d/m/Y ", dateFormat: "d/m/Y ", time_24hr: false});
});

/*for calculation and store the age field*/
Qualtrics.SurveyEngine.addOnPageSubmit(function(type) {
/* Place your JavaScript here to run when the page is submitted */
var dob = moment(jQuery("#"+this.questionId+" .InputText").val(), "DD/MM/YYYY");
var age = moment().diff(dob, 'months');
Qualtrics.SurveyEngine.setEmbeddedData('age', age);
});
Most people probably want the age in years, so you just need to change "months" to "years" here:
var age = moment().diff(dob, 'years');