WordPress Plugin – Grouping Your Tags (PHP5 and MySQL)

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2, as
    published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/?>
<?php

global $post_ID;

register_activation_hook(__FILE__, ‘taggroups_install’);

/* Actions */
add_action ( ‘admin_menu’, ‘render_tag_post_box’ );
add_action ( ‘pre_post_update’, ‘update_group_posts’ );

/*Filters*/
add_filter ( ‘the_content’, ‘get_postID’ );

/*********************************************************************************
        Runs every time the plugin is enabled by the admin of the wordpress site.
**********************************************************************************/

function taggroups_install () {
   global $wpdb;

/* Create the table that holds your Tag Group names and ID’s */

   $table_name = $wpdb->prefix . "group_term_groups";
        if($wpdb->get_var("SHOW TABLES LIKE ‘$table_name’") != $table_name)
        {
                $sql = "CREATE TABLE " . $table_name . " (
                  groupName TEXT NOT NULL,
                  groupID INT NOT NULL AUTO_INCREMENT PRIMARY KEY
                );";

        require_once(ABSPATH . ‘wp-admin/includes/upgrade.php’);
        dbDelta($sql);
        }

/* Create the table that holds your tags(terms) that are associated with groups */

   $table_name = $wpdb->prefix . "group_components";

        if($wpdb->get_var("SHOW TABLES LIKE ‘$table_name’") != $table_name)
        {
                $sql = "CREATE TABLE " . $table_name . " (
                  groupID INT,
                  termID INT
                );";

        dbDelta($sql);
        }

/* Create the table that holds the groups that are associated with your posts */

   $table_name = $wpdb->prefix . "group_posts";

        if($wpdb->get_var("SHOW TABLES LIKE ‘$table_name’") != $table_name)
        {
                $sql = "CREATE TABLE " . $table_name . " (
                  groupID INT,
                  postID INT
                );";

        dbDelta($sql);
        }
}

function render_tag_post_box()
{
                add_meta_box( ‘taggroup_sectionID’, ‘Tag Groups’, ‘taggroups_post_box’, ‘post’, ‘side’, ‘low’);
}       

/*********************************************************************************
        Generates the seletion box seen by the user when creating or modifying a
        Post. This box shows all groups and whether they are already enabled for
        the working Post.
**********************************************************************************/

function taggroups_post_box(){
        $checked_groups = NULL;
        $groups = NULL;
        $checked_groups = get_post_groups();
        $groups = fetch_groups();

        if (sizeof($checked_groups) > 0)
        {
                foreach ($groups as $group)
                {
                        $found = false;
                        foreach ($checked_groups as $checked_group)
                        {
                                if ($checked_group->groupID == $group->groupID)
                                {
                                        ?>
                                        <BR><input type="checkbox" id="<?php echo $group->groupID ?>" name="<?php echo $group->groupName ?>" value="1" checked />
                                        <?php
                                        echo $group->groupName;
                                        $found = true;
                                }
                        }
                        if ($found <> true){           
                                ?>
                                <BR><input type="checkbox" id="<?php echo $group->groupID ?>" name="<?php echo $group->groupName ?>" value="1" />
                                <?php
                                echo $group->groupName;
                        }                      
                }
        }
        ?><BR><BR><?php
        echo "Enable the groups that contain tags you want to include with your post.";
}

/*********************************************************************************
        Query table wp_group_term_groups and get all groups.
        Returns an array of groups.
**********************************************************************************/

function fetch_groups(){
        global $wpdb;
        $table_name = $wpdb->prefix . "group_term_groups";

        $groups = $wpdb->get_results("SELECT * FROM $table_name");
        return $groups;
}

/*********************************************************************************
        Query table wp_group_components and get all tags associated with a group.
**********************************************************************************/

function fetch_tags($groupID){
        global $wpdb;
        $table_name = $wpdb->prefix . "group_components";

        $comments = $wpdb->get_results("SELECT * FROM $table_name WHERE $groupID = groupID");
        return $comments;
}

/*********************************************************************************
        Loop through and find all group checkboxes that are enabled.
        Call write_group_posts to store these selections in the database.
**********************************************************************************/

function update_group_posts(){
        clear_group_posts();
        $groups = fetch_groups();
        foreach ($groups as $group){
                if(isset($_POST[$group->groupName])){
                        write_group_posts($group->groupID);
                }
        }
}

/*********************************************************************************
        Prior to calling write_group_posts, this function should be called to
        clear the groups that are associated with the working post. If it is not
        called, there is a possibility that groups will be associated multiple
        times per post.
**********************************************************************************/

function clear_group_posts(){
        global $wpdb;
        global $post_ID;

        $table_name = $wpdb->prefix . "group_posts";

        $sql = "DELETE FROM " . $table_name . " WHERE postID = $post_ID";
        $results = $wpdb->query($sql);
}

/*********************************************************************************
        Updates the database table wp_group_posts with all groups associated with
        the working post.
**********************************************************************************/

function write_group_posts($groupID){
        global $wpdb;
        global $post_ID;

        $table_name = $wpdb->prefix . "group_posts";
        $sql = "INSERT INTO " . $table_name . " VALUES ($groupID, $post_ID)";
        $results = $wpdb->query($sql);
}

/*********************************************************************************
        Stores the postID of the post the user is working on as a global variable
        from inside the WordPress loop for use later, when outside the loop.
**********************************************************************************/

function get_postID(){
        global $post;
        global $post_ID;
        $post_ID = $post->ID;
}

/*********************************************************************************
        Retrieve all groups that have been associated with a post.
        Returns an array of results.
**********************************************************************************/

function get_post_groups(){
        global $wpdb;
        global $post_ID;

        $table_name = $wpdb->prefix . "group_posts";
        $sql = "SELECT groupID FROM " . $table_name . " WHERE postID = $post_ID";
        $results = $wpdb->get_results($sql);
       
        return $results;
}
?>