Download After Submit

Enhance User Experience with Download After Submit

When it comes to online forms, ensuring that users have a seamless and satisfying experience is crucial. One common enhancement is allowing users to download a file following the successful submission of a form. This not only provides immediate feedback about their action but also serves as an effective way to deliver documents, such as whitepapers, brochures, or other resources. In this article, we will explore strategies and practical implementations for achieving a “Download After Submit” feature effectively.

Development

The core of this functionality lies in orchestrating both server-side and client-side processes. Your scenario involves using Craft CMS with a contact form plugin, and you already have the framework to trigger file downloads. Instead of directly redirecting or sending files inline, you can add an intermediate step that refreshes the page to show a success message before executing the download.

Set Up Event Listener

You have already set up an event listening mechanism using the onPost event listener. This essentially captures the submission event and triggers your download function when the data is stored successfully. However, to introduce an added layer of user experience — ensuring that users see a success message — you will need to amend the action after successful form submission.

Here’s how your event listener currently looks:

php
craft()->on('capture_submissions.onPost', array($this, 'triggerDownload'));

Implementing Confirmation Message

First, it is necessary to set a confirmation message once data has been successfully stored. You can achieve this by employing session flash messages. These messages can be displayed after a page reload.

Step 1: Setting Up Flash Message on Successful Submission

When you process the submission, once you confirm that the data is valid and has been stored, you could do something like this:

“`php
if ($formIsValid) {
// Store data
// Assuming $id is the identifier for the submission
// Set up the flash message
craft()->userSession->setFlash(‘successMessage’, ‘Thank you for your submission! Your download will start shortly.’);

// Redirect to the same page to show the message
craft()->request->redirect(craft()->request->url);

}
“`

In this setup, after the data is collected, we set a flash message that can be displayed on the page and redirect back to the form page.

Step 2: Displaying the Flash Message

Next, you’ll want to add functionality in your template — where the form resides — to check for this flash message.

twig
{% if craft.session.flash.successMessage %}
<div class="alert alert-success">
{{ craft.session.flash.successMessage }}
</div>
{% endif %}

This Twig code snippet will check if a success message is present and display it on the page.

Triggering the File Download

While the above steps will manage showing a message to the user, triggering the download in a user-friendly manner is the next challenge. Since you want to distribute a file after a page refresh, we can utilize JavaScript to initiate the download post-submission.

Step 3: Using JavaScript to Trigger the Download

Once the page is reloaded and displays the success message, you can use JavaScript to delay the downloading action a bit, allowing users to read the message first.

For example, include a script at the bottom of your template:

“`html

document.addEventListener(‘DOMContentLoaded’, function() {
// Check if the success message exists
if (document.querySelector(‘.alert.alert-success’)) {
// Wait a couple of seconds before triggering the download
setTimeout(function() {
// Redirect to the download URL
window.location.href = ‘{{ url(‘myplugin/whitepaper/download’, { id: id }) }}’;
}, 2000); // Adjust timeout as necessary
}
});

“`

In the script above, we wait for the DOM content to load, check if there’s a success message present, and then initiate the file download using the URL you specified.

Download Controller Action

You would need a controller method that handles the file retrieval. This is typically defined in your plugin controller class:

“`php
public function actionDownload()
{
$id = craft()->request->getParam(‘id’);

// Retrieve the file you’d like to serve
$filePath = ...; // Logic to determine file path based on ID

// Check if the file exists
if (file_exists($filePath)) {
    craft()->request->sendFile('application/pdf', file_get_contents($filePath), array('filename' => 'yourfile.pdf', 'forceDownload' => true));
} else {
    throw new HttpException(404);
}

}
“`

This action would need to retrieve the appropriate file based on the submission ID and send the appropriate headers to trigger a download.

Combining All Elements

Once everything is in place, you should have a smooth workflow:

1. The user fills out the form and submits it.
2. The form processes the submission, saves it, and sets a success message through a flash session.
3. The user is redirected back to the form page, where they see the success message.
4. After a brief pause, JavaScript kicks in and triggers the download for the file, making it a seamless experience.

Performance and Considerations

Implementing this download mechanism ensures users feel their submission has been acknowledged with immediate feedback. All these processes help in providing a seamless experience. However, it’s vital to consider scalability—ensure that your file retrieval mechanism is optimized for performance as the user base grows, especially if they are expecting large documents.

Additionally, always test different scenarios. For instance, what if a user submits the form multiple times? How does that affect each step? Proper handling of such dynamics ensures a robust user interaction without confusion.

Moreover, ensuring proper error handling will provide more resilience when users encounter issues — for instance, if the downloaded file is not found.

By enhancing your form submission with a well-structured approach to file downloads, you shine through in providing a thoughtful user experience that transforms what can often be an overlooked detail into a core part of user satisfaction.