Functions are causing errors

Question

I'm declaring a function on a plugin's PHP. The plugin loads code at the top of each post (Post Layout is the plugins name).

Cannot redeclare vote_up() (previously declared in /home/content/08/10290908/html/wp-content/plugins/post-layout/plugin.php(181) : eval()'d code:4) in /home/content/08/10290908/html/wp-content/plugins/post-layout/plugin.php(181) : eval()'d code on line 36

that's the displayed error message, it isnt because the function has already been declared in the functions.php (I know because I tested it by renaming it to all sorts of names) It says it's already declared in the plugin I'm using to load the code.

Heres the code:

<?php 

function vote_up(){
                    if($post_vote == "9"){

        }
        elseif($post_vote == "8"){
        update_post_meta( get_the_ID(), 'post_vote', '9', '8');
        }
        elseif($post_vote == "7"){
        update_post_meta( get_the_ID(), 'post_vote', '8', '7');
        }
        elseif($post_vote == "6"){
        update_post_meta( get_the_ID(), 'post_vote', '7', '6');
        }
        elseif($post_vote == "5"){
        update_post_meta( get_the_ID(), 'post_vote', '6', '5');
        }
        elseif($post_vote == "4"){
        update_post_meta( get_the_ID(), 'post_vote', '5', '4');
        }
        elseif($post_vote == "3"){
        update_post_meta( get_the_ID(), 'post_vote', '4', '3');
        }
        elseif($post_vote == "2"){
        update_post_meta( get_the_ID(), 'post_vote', '3', '2');
        }
        elseif($post_vote == "1"){
        update_post_meta( get_the_ID(), 'post_vote', '2', '1');
        }
        elseif($post_vote == "0"){
        update_post_meta( get_the_ID(), 'post_vote', '1', '0');
        }
            else{//do nothing
        };
}

//if the post is pending show
if(get_post_status() == 'pending') {

//if the user is logged in show
if ( is_user_logged_in() ) {

    add_post_meta( get_the_ID(), 'post_vote', '0', true );
    $post_vote = get_post_meta( get_the_ID(), 'post_vote', true );

    echo 'Votes: ' . $post_vote;

           echo ' <form action="xxx" method="post" onclick="return vote_up()">';
           echo ' <input type="button" value="Vote Up" />';
           echo '</form>';


} else {
    echo'Please Sign in to Vote';
}

} else {
// do nothing
}


?>

The code above is basically trying to make it so that when you click on the button, the vote meta_key goes up by one. It's for voting so once 10 users vote on it, it will publish.

This stupid buttons such a hassle, I can't move on until I have it working even tried to pay some guy to fix the button and he didn't have a clue

Answer 1

You don't want to add function vote_up() { [...] } at the top of every post if you display more than one post on a page. You want to declare the vote_up() function in your plugin's PHP file.

Once the plugin declares the function, as long as the plugin is active, you can just call the function wherever you need it.

I would however suggest two further changes:

• Prefix the function name.

vote_up is rather generic, and you run the risk of colliding with other plugins and/or themes. Something like [plugin_name]_vote_up() would work nicely.

• Check to make sure the function exists before using it.

If you call vote_up anywhere outside the plugin (e.g. a theme template file), surround the call as follows:

if ( function_exists( 'vote_up' ) ) {
    vote_up();
}

This will ensure that your theme files will still function properly if you ever need/want to deactivate the plugin for some reason.