Creating wp plugin for external login => post comments

Question

I need to create a wordpress plugin to connect wordpress to a central login. But all I want is the user to be able to post comments with name and email filled. I don't think I need create a real loggin into wordpress because the user should not be able to write posts or do admin stuff. I want him only to post comments.

I search the documentation but could not find any action for comments.

How can I change the html of a comment form?

Answer 1

Maybe not good but it works...

Fill comment author and email from central login stored in session:

function portal_user_comment()
{
    $_POST['author'] = $_SESSION['portal']['name'];
    $_POST['email'] = $_SESSION['portal']['email'];
}
add_action('pre_comment_on_post', 'portal_user_comment');

Edit comments.php from the template. Look for:

<input type="text" name="author" id="author" value="<?php $comment_author; ?>" ...>
<input type="text" name="email" id="email" value="<?php $comment_author_email; ?>" ...>

Set both fields disabled="true" and replace the values with the author and email from the session.