dagsplug/plug_update_plugin.php

<?php

if (!class_exists("plug_update_plugin")) {
	class plug_update_plugin {	
		function plug_update_plugin($ns) {
			$this->title = __("Update plugin","dagsopt");

		$this->pluginname = $ns->pluginname;
		$this->file = $ns->file;
		$this->ns = $ns;
		}

	function start(){
		register_activation_hook ( plugin_basename($this->file), array (	&$this, 'activatePlugin' ) );
		register_deactivation_hook ( plugin_basename($this->file), array ( &$this, 'deactivatePlugin' ) );

		add_action($ns->pluginname.'UpdateCheck', array(&$this,'check_update'));
		add_filter( 'http_request_args', array(&$this,'updates_exclude'), 5, 2 );
		if(isset($_REQUEST["checkforupdates"])){
			$this->check_update();
		}
	}

 
	function activatePlugin() {
		wp_schedule_event(time(), 'hourly', $this->pluginname.'UpdateCheck' );
	}
	function deactivatePlugin() {
		wp_clear_scheduled_hook ( $this->pluginname.'UpdateCheck');
	}

	/*SELF UPDATE*/
	function check_update() {
		global $wp_version;
		$plugin_folder = plugin_basename( dirname( $this->file ) );
		$plugin_file = basename( ( $this->file ) );
		if ( defined( 'WP_INSTALLING' ) ) return false;
		$response = wp_remote_get( $this->ns->update_check_url );
		list($version, $url) = explode('|', $response['body']);
		$url = "https://git.tum.dk/tum.dk/dagsplug/archive/".$version.".zip";

		$this->status = 'Remote version: '.$version." URL: ".$url.":::";

		$this->possible = false;
		if($this->plugin_get("Version") == $version) return false;
		$this->possible = true;
		$plugin_transient = get_site_transient('update_plugins');
		$a = array(
			'slug' => $plugin_folder,
			'new_version' => $version,
			'url' => $this->plugin_get("AuthorURI"),
			'package' => $url
		);
		$o = (object) $a;
		$plugin_transient->response[$plugin_folder.'/'.$plugin_file] = $o;
		set_site_transient('update_plugins', $plugin_transient);
	}
	function updates_exclude( $r, $url ) {
		if ( 0 !== strpos( $url, 'http://api.wordpress.org/plugins/update-check' ) )
			return $r; // Not a plugin update request. Bail immediately.
		$plugins = unserialize( $r['body']['plugins'] );
		unset( $plugins->plugins[ plugin_basename( $this->file ) ] );
		unset( $plugins->active[ array_search( plugin_basename( $this->file ), $plugins->active ) ] );
		$r['body']['plugins'] = serialize( $plugins );
		return $r;
	}
	function plugin_get($i) {
		if ( ! function_exists( 'get_plugins' ) )
			require_once( ABSPATH . 'wp-admin/includes/plugin.php' );
		$plugin_folder = get_plugins( '/' . plugin_basename( dirname( $this->file ) ) );
		$plugin_file = basename( ( $this->file ) );
		return $plugin_folder[$plugin_file][$i];
	}

	
	function admin_line(){
		  ?>
		  <a href="/wp-admin/admin.php?page=dagsopt-options&checkforupdates"><?php echo(__("Check for updates","dagsopt")) ?></a>
		  <br>
		  <?php echo($this->status); ?>
 
		  <?php 
		  
		  
		  	if ( current_user_can('update_plugins')  && $this->possible) {
					$url = wp_nonce_url(self_admin_url('update.php?action=upgrade-plugin&plugin=' . $this->ns->filename), 'upgrade-plugin_' .$this->ns->filename);
					echo('<a href="'.$url.'">'.__("Update","dagsopt").'</a>');
				}
		  ?>
		  
		  
		  <?php  
		}
	}

	global $plug_update_plugin;
	$plug_update_plugin = new plug_update_plugin($this);		
	$this->dagsopt['plug_update_plugin'] = $plug_update_plugin;
			
}