How to add hidden field to comment form

Hey Carole,

Thanks for reaching out to us.

You can change any field to a hidden field by changing the value of “Type” field to “hidden”.

For e.g. the following field is a checkbox.

<input type="checkbox" name="_mc4wp_lists[]" value="ListIDgoeshere" />

This can be made to a hidden field by changing the type property.

<input type="hidden" name="_mc4wp_lists[]" value="ListIDgoeshere" />

I hope that answers your query. Let us know if you have any further questions.

• This reply was modified 5 years, 6 months ago by Harish Chouhan.

I guess I should have been more specific. ??

I’d like to add a hidden field for a custom field called “SIGNUP” to the comments section on my site using your comment form integration.

However, I don’t know how to tell your plugin how to do that.

I’ve I tried adding a custom sign-up form in functions.php:

function output_hidden_field_in_comment_form() {
  ?>
    <label>
      <input type="checkbox" name="mc4wp-subscribe" value="1" />
      Subscribe to my newsletter.
    </label>
    <input type="hidden" name="mc4wp-SIGNUP" value="Comments">
  <?php
}
add_action( 'comment_form', 'output_hidden_field_in_comment_form' );

I’ve tried SIGNUP and mc4wp-SIGNUP as the name to my hidden form.

Is there some version of _mc4wp_lists[] I should be using?

Here’s I got it working. I added the following code to functions.php:

// Add signup location to comments subscribe checkbox
add_filter( 'comment_form_field_email', 'my_comment_form_field_email' );
function my_comment_form_field_email( $email_field ) {
    return $email_field.'<label><input type="checkbox" name="mc4wp-subscribe" value="1" />Subscribe to my newsletter.</label><input type="hidden" name="mc4wp-SIGNUP" value="Comments">';
}

This looks for the email field, adds the checkbox below it, and correctly attributes my hidden field in mailchimp.

I found this solution based on this answer in stackexchange: https://wordpress.stackexchange.com/a/127030