Adsense by author with middle content.

adsense-by-author.php

<?php
/**
 * Plugin Name: Adsense by Author
 * Plugin URI: http://claudiosmweb.com/
 * Description: Adsense by Author.
 * Author: claudiosanches
 * Author URI: http://claudiosmweb.com/
 * Version: 1.1
 * License: GPLv2 or later
 * Text Domain: adbyauthor
 * Domain Path: /languages/
 */

class Adsense_By_Author {

    public function __construct() {

        // Actions.
        add_action( 'show_user_profile', array( &$this, 'add_profile_fields' ) );
        add_action( 'edit_user_profile', array( &$this, 'add_profile_fields' ) );
        add_action( 'personal_options_update', array( &$this, 'save_profile_fields' ) );
        add_action( 'edit_user_profile_update', array( &$this, 'save_profile_fields' ) );

        // Filters.
        add_filter( 'the_content', array( &$this, 'insert_blocks' ) );
    }

    /**
     * Add profile fields.
     */
    public function add_profile_fields( $user ) {
        ?>
        <h3><?php _e( 'Banners de publicidade', 'adbyauthor' ); ?></h3>
        <table class="form-table">
            <tr>
                <th><label for="banner_top"><?php _e( 'Banner topo', 'adbyauthor' ); ?></label></th>
                <td>
                    <textarea cols="30" rows="5" id="banner_top" name="banner_top"><?php echo esc_attr( get_the_author_meta( 'banner_top', $user->ID ) ); ?></textarea>
                    <br /><span class="description"><?php _e( 'Banner da in&iacute;cio do post.', 'adbyauthor' ); ?></span>
                </td>
            </tr>
            <tr>
                <th><label for="banner_content"><?php _e( 'Banner conte&uacute;do', 'adbyauthor' ); ?></label></th>
                <td>
                    <textarea cols="30" rows="5" id="banner_content" name="banner_content"><?php echo esc_attr( get_the_author_meta( 'banner_content', $user->ID ) ); ?></textarea>
                    <br /><span class="description"><?php _e( 'Banner do meio do conte&uacute;do.', 'adbyauthor' ); ?></span>
                </td>
            </tr>
            <tr>
                <th><label for="banner_bottom"><?php _e( 'Banner rodap&eacute;', 'adbyauthor' ); ?></label></th>
                <td>
                    <textarea cols="30" rows="5" id="banner_bottom" name="banner_bottom"><?php echo esc_attr( get_the_author_meta( 'banner_bottom', $user->ID ) ); ?></textarea>
                    <br /><span class="description"><?php _e( 'Banner do rodap&eacute; do post.', 'adbyauthor' ); ?></span>
                </td>
            </tr>
        </table>
        <?php
    }

    /**
     * Save profile fields.
     */
    public function save_profile_fields( $user_id ) {
        if ( ! current_user_can( 'edit_user', $user_id ) ) {
            return false;
        }

        update_usermeta( $user_id, 'banner_top', $_POST['banner_top'] );
        update_usermeta( $user_id, 'banner_bottom', $_POST['banner_bottom'] );
        update_usermeta( $user_id, 'banner_content', $_POST['banner_content'] );
    }

    /**
     * Insert banners in the_content.
     */
    public function insert_blocks( $content ) {

        if ( is_single() ) {
            $banner_top = '<div class="banner-author" id="banner-top" style="clear: both; margin-bottom: 20px;">' . get_the_author_meta( 'banner_top' ) . '<div style="clear: both"></div></div>';
            $banner_content = '<div class="banner-author" id="banner-content" style="clear: both; margin-bottom: 20px;">' . get_the_author_meta( 'banner_content' ) . '<div style="clear: both"></div></div>';
            $banner_bottom = '<div class="banner-author" id="banner-bottom" style="clear: both; margin-bottom: 20px;">' . get_the_author_meta( 'banner_bottom' ) . '<div style="clear: both"></div></div>';

            $new_content = '';

            $content = explode( '</p>', $content );
            $total = count( $content );
            $middle = floor( $total / 2 );

            for ( $i = 0; $i < $total; $i++ ) {

                if ( $i == $middle ) {
                    $new_content .= $banner_content;
                }

                // Prevents extra closure of paragraph.
                if ( $i >= ( $total - 1 ) ) {
                    $new_content .= $content[$i];
                } else {
                    $new_content .= $content[$i] . '</p>';
                }
            }

            // Set the new content.
            $content = $banner_top . $new_content . $banner_bottom;
        }

        return $content;
    }

} // close Adsense_By_Author class.

new Adsense_By_Author;