Register which image has been clicked in form

Question

I have multiple images in a HTML document and I want them to render unique values when they are clicked (in some retrievable way). I have tried having them as form elements, like so:

<form id="myform" method="post" action="">
    <input type="hidden" name="action" value="submit" />
    <div class="flex-item"><input type="image" name="submit" value="alt1" alt="alt1" src="images/<?php echo $data[$counter] ?>"></div>
    <div class="flex-item"><input type="image" name="submit" value="alt2" alt="alt2" src="images/<?php echo $data[$counter+1] ?>"></div>
</form>

In this case I would like to access the POST data with PHP, something like:

if (isset($_POST['action'])) {
    echo '<br />The ' . $_POST['submit'] . ' button was pressed';
}

But this doesn't work, as it's the image input type, which doesn't seem to be able to send data. I have tried using a button with the image as background, but this way I would have to adapt the size of each image to make it fit in the button (which I want to avoid, as I have many images).

I know I could use an image as a submit button with Javascript, but as I said, information about which image has been clicked also needs to be available somehow. Any ideas about the best solution?

Answer 1

HTML / CSS - Only way.

Set up the CSS to hide the radio buttons:

.hidden {
    display: none !important;
}

In your form, use radio buttons to track which image is selected. Put the image inside of a label that is "for" the relevant radio button . Be sure to put whatever info you want in PHP inside the value attribute of the radio buttons:

<form method="post" name="myForm">
    <div>
        <input type="radio" name="image" value="image1" id="image1" class="hidden">
        <label for="image1"><img src="path-to-your-image.jpg"></label>
    </div>
    <div>
        <input type="radio" name="image" value="image2" id="image2" class="hidden">
        <label for="image2"><img src="path-to-your-other-image.jpg"></label>
    </div>
    <div>
        <input type="submit" name="save" value="Save Image Selection">
    </div>
</form>

If you need the form to submit when they click an image, then add this bit of javascript:

<script>
    // No-conflict-mode-safe document ready function (waits until page is loaded to run, which ensures radio buttons are available to bind to)
    jQuery(function($) {
        // Hide / suppress the submit button
        $('input[type="submit"]').closest('div').hide();
        // Bind to change event for all radio buttons
        $('input[type="radio"]').on('change', function() {
            // Submit the form ("this" refers to the radio button)
            $(this).closest('form').submit();
        });
    });
</script>

Then, when you submit this form, in your PHP you'd be able to do this:

$image = $_POST[ 'image' ]; // 'image' is the name of the radio buttons
var_dump( $image );
// Will result in "image1" or "image2", etc - whatever "value" you assigned to the radio buttons

Answer 2

When you use your code, you get the submit param (because of the button's attribute name ) in your $_POST object. The value will be the value attribute.

So you can check this like this:

<form id="myform" method="post" action="">
    <input type="hidden" name="action" value="submit" />
    <div class="flex-item"><input type="image" name="submit" value="alt1" alt="alt1" src="images/img1"></div>
    <div class="flex-item"><input type="image" name="submit" value="alt2" alt="alt2" src="images/img2"></div>
</form>

<?php
if (isset($_POST['submit'])) {
    if ($_POST['submit'] == 'alt1') {
        echo 'alt1 clicked';
            // First button clicked 
    }
    else {
        echo 'alt2 clicked';
            // second button clicked
    }
}
?>