Enable authors to edit their own posts and not others

<?php

/*
Plugin Name: Live Edit
Plugin URI: http://www.elliotcondon.com/
Description: Edit the title, content and any ACF fields from the front end of your website!
Version: 2.0.0
Author: Elliot Condon
Author URI: http://www.elliotcondon.com/
License: GPL
Copyright: Elliot Condon
*/

$live_edit = new live_edit();

class live_edit
{
    var $dir,
        $path,
        $version,
        $acf_version,
        $data;


    /*
    *  Constructor
    *
    *  @description:
    *  @since 1.0.0
    *  @created: 23/06/12
    */

    function __construct()
    {

        // vars
        $this->dir = plugins_url('',__FILE__);
        $this->path = plugin_dir_path(__FILE__);
        $this->version = '2.0.0';
        $this->defaults = array(
            'panel_width'   =>  600,
        );

        foreach( $this->defaults as $k => $v )
        {
            $db_v = get_option('live_edit_' . $k, $v);

            if( $db_v )
            {
                $v = $db_v;
            }

            $this->data[ $k ] = $v;
        }


        // set text domain
        load_plugin_textdomain('live-edit', false, basename(dirname(__FILE__)).'/lang' );


        // actions
        add_action('init', array($this,'init'));


        return true;
    }


    /*
    *  init
    *
    *  @description:
    *  @created: 7/09/12
    */

    function init()
    {
        // must be logged in
        if( is_user_logged_in() )
        {
            // actions
            add_action('admin_head', array($this,'admin_head'));
            add_action('admin_menu', array($this,'admin_menu'));


            add_action('wp_enqueue_scripts', array($this,'wp_enqueue_scripts'));
            add_action('wp_head', array($this,'wp_head'));
            add_action('wp_footer', array($this,'wp_footer'));
            add_action('wp_ajax_live_edit_update_width', array($this, 'ajax_update_width'));
        }
    }


    /*
    *  admin_head
    *
    *  @description:
    *  @since 1.0.0
    *  @created: 25/07/12
    */

    function admin_head()
    {
        echo '<style type="text/css">#menu-settings a[href="options-general.php?page=live-edit-panel"] { display:none; }</style>';
    }


    /*
    *  admin_menu
    *
    *  @description:
    *  @since 1.0.0
    *  @created: 25/07/12
    */

    function admin_menu()
    {
        global $pagenow;

        $slug = add_options_page(__("Live Edit Panel",'le'), __("Live Edit Panel",'le'), 'edit_posts', 'live-edit-panel', array($this, 'view_panel'));


        if( $pagenow == 'options-general.php' && isset($_GET['page']) && $_GET['page'] == 'live-edit-panel')
        {
            add_action('admin_enqueue_scripts', array($this, 'page_admin_enqueue_scripts'));
            add_action('admin_head', array($this, 'page_admin_head'));
        }
    }


    /*
    *  admin_enqueue_scripts
    *
    *  @description: run after post query but before any admin script / head actions. A good place to register all actions.
    *  @since: 3.6
    *  @created: 26/01/13
    */

    function page_admin_enqueue_scripts()
    {
        // actions
        do_action('acf/input/admin_enqueue_scripts');
    }


    /*
    *  save_post
    *
    *  {description}
    *
    *  @since: 4.0.3
    *  @created: 16/05/13
    */

    function save_post()
    {
        // validate
        if( !isset($_POST['post_id']) )
        {
            return;
        }


        // vars
        $post_id = $_POST['post_id'];
        $post_data = array();


        foreach( array('post_title', 'post_content', 'post_excerpt') as $v )
        {
            if( isset($_POST['fields'][ $v ]) )
            {
                $post_data[ $v ] = $_POST['fields'][ $v ];

                unset( $_POST['fields'][ $v ] );
            }
        }


        // update post
        if( !empty($post_data) )
        {
            $post_data['ID'] = $post_id;
            wp_update_post( $post_data );
        }


        // save custom fields
        do_action('acf/save_post', $post_id);


        // set var
        $this->data['save_post'] = true;

    }


    /*
    *  page_admin_head
    *
    *  @description:
    *  @since: 3.6
    *  @created: 17/03/13
    */

    function page_admin_head()
    {
        // save
        if( isset($_POST['nonce']) && wp_verify_nonce($_POST['nonce'], 'live-edit') )
        {
            $this->save_post();
        }


        // vars
        $options = array(
            'fields' => false,
            'post_id' => 0,
        );
        $options = array_merge($options, $_GET);


        // global vars
        global $acf;


        // Style
        echo '<link rel="stylesheet" type="text/css" href="'.$this->dir.'/css/style.admin.css?ver=' . $this->version . '" />';


        // Javascript
        echo '<script type="text/javascript" src="'.$this->dir.'/js/functions.admin.js?ver=' . $this->version . '" ></script>';


        do_action('acf/input/admin_head');


    }


    /*
    *  wp_enqueue_scripts
    *
    *  @description:
    *  @since 1.0.0
    *  @created: 25/07/12
    */

    function wp_enqueue_scripts() {

        wp_enqueue_script(array(
            'jquery',
            'jquery-ui-core',
            'jquery-ui-widget',
            'jquery-ui-mouse',
            'jquery-ui-resizable'
        ));

    }


    /*
    *  wp_head
    *
    *  @description:
    *  @since 1.0.0
    *  @created: 25/07/12
    */

    function wp_head()
    {
        // Javascript
        echo '<script type="text/javascript">
            var live_edit = {
                ajaxurl : "' . admin_url( 'admin-ajax.php' ) . '",
                panel_url : "' . admin_url( 'options-general.php?page=live-edit-panel' ) . '",
                panel_width : ' . $this->data['panel_width'] . '
            };
        </script>';
        echo '<script type="text/javascript" src="' . $this->dir . '/js/functions.front.js?ver=' . $this->version . '" ></script>';


        // Style
        echo '<link rel="stylesheet" type="text/css" href="' . $this->dir . '/css/style.front.css?ver=' . $this->version . '" />';

    }


    /*--------------------------------------------------------------------------------------
    *
    *   wp_footer
    *
    *   @author Elliot Condon
    *   @since 1.0.0
    *
    *-------------------------------------------------------------------------------------*/

    function wp_footer()
    {
        ?>
        <div id="live_edit-panel">
            <div id="live_edit-iframe-cover"></div>
            <iframe id="live_edit-iframe"></iframe>
        </div>
        <div id="live_edit-vail"></div>
        <?php

    }


    /*--------------------------------------------------------------------------------------
    *
    *   ajax_update_width
    *
    *   @author Elliot Condon
    *   @since 1.0.0
    *
    *-------------------------------------------------------------------------------------*/

    function ajax_update_width()
    {
        // vars
        $options = array(
            'live_edit_panel_width' => 600
        );

        $options = array_merge($options, $_POST);


        // update option
        update_option( 'live_edit_panel_width', $options['panel_width'] );


        echo "1";
        die;
    }


    /*
    *  render_live_edit_panel
    *
    *  @description:
    *  @created: 7/09/12
    */

    function view_panel()
    {
        global $acf;


        // vars
        $options = array(
            'fields' => false,
            'post_id' => 0,
        );
        $options = array_merge($options, $_GET);


        // validate
        if( !$options['post_id'] )
        {
            wp_die( "Error: No post_id parameter found" );
        }

        if( !$options['fields'] )
        {
            wp_die( "Error: No fields parameter found" );
        }


        // loop through and load all fields as objects
        $fields = explode(',',$options['fields']);

        if( $fields )
        {
            foreach( $fields as $k => $field_name )
            {
                $field = null;


                if( $field_name == "post_title" ) // post_title
                {
                    $field = array(
                        'key' => 'post_title',
                        'label' => 'Post Title',
                        'name' => 'post_title',
                        'value' => get_post_field('post_title', $options['post_id']),
                        'type'  =>  'text',
                        'required' => 1
                    );
                }
                elseif( $field_name == "post_content" ) // post_content
                {
                    $field = array(
                        'key' => 'post_content',
                        'label' => 'Post Content',
                        'name' => 'post_content',
                        'value' => get_post_field('post_content', $options['post_id']),
                        'type'  =>  'wysiwyg',
                    );
                }
                elseif( $field_name == "post_excerpt" ) // post_excerpt
                {
                    $field = array(
                        'key' => 'post_excerpt',
                        'label' => 'Post Excerpt',
                        'name' => 'post_excerpt',
                        'value' => get_post_field('post_excerpt', $options['post_id']),
                        'type'  =>  'textarea',
                    );
                }
                else // acf field
                {
                    $field = get_field_object( $field_name, $options['post_id'], array( 'load_value' => false, 'format_value' => false ));
                }


                // load defualts (for post_title, etc)
                $field = apply_filters('acf/load_field_defaults', $field);

                $fields[ $k ] = $field;
            }
        }

        // render fields
?>
<div class="wrap no_move">

    <?php if( isset($this->data['save_post']) ): ?>
        <div class="inner-padding">
            <div id="message" class="updated"><p><?php _e("Fields updated", 'live-edit'); ?></p></div>
        </div>
    <?php endif; ?>

    <form id="post" method="post" name="post">

        <div style="display:none;">
            <input type="hidden" name="post_id" value="<?php echo $options['post_id']; ?>" />
            <input type="hidden" name="nonce" value="<?php echo wp_create_nonce( 'live-edit' ); ?>" />
        </div>
        <div class="metabox-holder" id="poststuff">

            <!-- Main -->
            <div id="post-body">
            <div id="post-body-content">
                <div class="acf_postbox">

                    <?php

                    do_action('acf/create_fields', $fields, $options['post_id']);

                    ?>

                    <div id="field-save">
                        <ul class="hl clearfix">
                            <li>
                                <a class="le-button grey" href="#" id="live_edit-close">
                                    <?php echo isset($this->data['save_post']) ? __("Close", 'live-edit') : __("Cancel", 'live-edit') ?>
                                </a>
                            </li>
                            <li class="right">
                                <input type="submit" name="live_edit-save" class="le-button" id="live_edit-save" value="<?php esc_attr_e("Update", 'live-edit') ?>" />
                            </li>
                            <li class="right" id="saving-message">
                                <?php _e("Saving", 'live-edit'); ?>...
                            </li>
                        </ul>
                    </div>

                </div>
            </div>
            </div>

        </div>
    </form>

    <?php if( isset($this->data['save_post']) ): ?>
        <script type="text/javascript">
        (function($){

        // does parent exist?
        if( !parent )
        {
            return;
        }

        // update the div
        parent.live_edit.update_div();

        })(jQuery);
        </script>
    <?php endif; ?>

</div>
<?php

    }

}


/*
*  live_edit
*
*  @description:
*  @since 1.0.0
*  @created: 25/07/12
*/

function live_edit( $fields = false, $post_id = false )
{
    // validate fields
    if( !$fields )
    {
        return false;
    }


    // filter post_id
    $post_id = acf_filter_post_id( $post_id );


    // turn array into string
    if( is_array($fields) )
    {
        $fields = implode(',', $fields);
    }


    // remove any white spaces from $fields
    $fields = str_replace(' ', '', $fields);


    // build atts
    $atts = ' data-live_edit-fields="' . $fields . '" data-live_edit-post_id="' . $post_id . '" ';


    // echo
    echo $atts;

}

?>