When working with Google Apps Script to handle form submissions, many developers encounter a frustrating problem where the event object (e) appears to be undefined. This issue can create confusion, especially when trying to access the submitted data from Google Forms. In this article, we will explore this problem in-depth, provide the original code that often leads to this confusion, and analyze how to fix it for effective form handling.
The Original Problem
Example Code
function onFormSubmit(e) {
Logger.log(e.values);
}
In the example above, the function onFormSubmit(e) is designed to log the values submitted through a Google Form. However, many users find that e is undefined, leading to errors when they try to access e.values.
Understanding the Issue
The issue arises because the onFormSubmit(e) function does not automatically receive an event object (e) when it is called manually (e.g., from the script editor). The function is intended to be triggered automatically by the Google Form submission event. If you try to run it directly from the Apps Script editor, the e object will not be defined, resulting in the error.
How to Properly Use the Form Submission Event Object
To ensure that you receive the event object correctly, you need to set up a trigger in Google Apps Script that listens for form submissions. Follow these steps:
-
Open your Google Form: Access the form for which you want to capture submissions.
-
Go to Script Editor: Click on the three dots in the upper right corner of the form, navigate to "Script editor."
-
Set Up a Trigger:
- In the script editor, click on the clock icon (Triggers) on the left sidebar.
- Click on "+ Add Trigger."
- Select the function
onFormSubmit, choose "From form" as the event source, and select "On form submit" as the event type.
-
Save the Trigger: This will ensure that your function runs automatically every time a form submission occurs.
Updated Example Code
Here’s the corrected and optimized code for handling form submissions:
function onFormSubmit(e) {
// Check if event object is defined
if (!e) {
Logger.log('Event object is undefined!');
return;
}
// Extract submitted values
const submittedData = e.values;
// Log the submitted data
Logger.log('Submitted Data: ' + submittedData.join(', '));
// Additional processing can be done here
}
Analyzing the Code
Key Points to Note:
- Event Object Check: Always ensure that the event object
(e)is defined before trying to access its properties. This prevents errors and allows for better debugging. - Logging: Use
Logger.log()to keep track of the data received from the form submission, which can be useful for debugging purposes. - Processing Data: You can add additional functionality within the function to process the submitted data as needed, such as sending emails, updating spreadsheets, etc.
Practical Example: Sending a Confirmation Email
Let’s take our onFormSubmit function a step further by sending a confirmation email when the form is submitted:
function onFormSubmit(e) {
if (!e) {
Logger.log('Event object is undefined!');
return;
}
const submittedData = e.values;
Logger.log('Submitted Data: ' + submittedData.join(', '));
const emailAddress = submittedData[1]; // Assuming the second field is the email
const subject = 'Thank you for your submission!';
const body = 'We have received your submission: \n' + submittedData.join('\n');
MailApp.sendEmail(emailAddress, subject, body);
}
Additional Resources
To further enhance your understanding of Google Apps Script and form submissions, consider the following resources:
Conclusion
Handling Google Forms using Google Apps Script can significantly enhance productivity and automate workflows. Understanding how to work with the form submission event object (e) is crucial to avoid common pitfalls like undefined errors. By following the proper setup and code structure, you can leverage the full potential of Google Apps Script to streamline your data collection processes effectively.
If you have any additional questions or need help with your script, feel free to leave a comment!
