{"id":6677,"date":"2014-04-21T12:51:32","date_gmt":"2014-04-21T12:51:32","guid":{"rendered":"https:\/\/unknownerror.org\/index.php\/2014\/04\/21\/creating-back-page-links-in-codeigniter-collection-of-common-programming-errors-2\/"},"modified":"2014-04-21T12:51:32","modified_gmt":"2014-04-21T12:51:32","slug":"creating-back-page-links-in-codeigniter-collection-of-common-programming-errors-2","status":"publish","type":"post","link":"https:\/\/unknownerror.org\/index.php\/2014\/04\/21\/creating-back-page-links-in-codeigniter-collection-of-common-programming-errors-2\/","title":{"rendered":"creating back page links in Codeigniter-Collection of common programming errors"},"content":{"rendered":"

I extend the session class by creating \/application\/libaries\/MY_Session.php<\/code><\/p>\n

class MY_Session extends CI_Session {\n\n    function __construct() {\n        parent::__construct();\n\n        $this->tracker();\n    }\n\n    function tracker() {\n        $this->CI->load->helper('url');\n\n        $tracker =& $this->userdata('_tracker');\n\n        if( !IS_AJAX ) {\n            $tracker[] = array(\n                'uri'   =>      $this->CI->uri->uri_string(),\n                'ruri'  =>      $this->CI->uri->ruri_string(),\n                'timestamp' =>  time()\n            );\n        }\n\n        $this->set_userdata( '_tracker', $tracker );\n    }\n\n\n    function last_page( $offset = 0, $key = 'uri' ) {   \n        if( !( $history = $this->userdata('_tracker') ) ) {\n            return $this->config->item('base_url');\n        }\n\n        $history = array_reverse($history); \n\n        if( isset( $history[$offset][$key] ) ) {\n            return $history[$offset][$key];\n        } else {\n            return $this->config->item('base_url');\n        }\n    }\n}\n<\/code><\/pre>\n
And then to retrieve the URL of the last page visited you call<\/p>\n
$this->session->last_page();\n<\/code><\/pre>\n
And you can increase the offset and type of information returned etc too<\/p>\n
$this->session->last_page(1); \/\/ page before last\n$this->session->last_page(2); \/\/ 3 pages ago\n<\/code><\/pre>\n
The function doesn’t add pages called using Ajax to the tracker but you can easily remove the if( !IS_AJAX )<\/code> bit to make it do so.<\/p>\n
Edit: If you run to the error Undefined constant IS_AJAX, assumed IS_AJAX add the line below to \/application\/config\/constants.php<\/code><\/p>\n
define('IS_AJAX', isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest');\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
I extend the session class by creating \/application\/libaries\/MY_Session.php class MY_Session extends CI_Session { function __construct() { parent::__construct(); $this->tracker(); } function tracker() { $this->CI->load->helper(‘url’); $tracker =& $this->userdata(‘_tracker’); if( !IS_AJAX ) { $tracker[] = array( ‘uri’ => $this->CI->uri->uri_string(), ‘ruri’ => $this->CI->uri->ruri_string(), ‘timestamp’ => time() ); } $this->set_userdata( ‘_tracker’, $tracker ); } function last_page( $offset = 0, $key […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-6677","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/6677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/comments?post=6677"}],"version-history":[{"count":0,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/posts\/6677\/revisions"}],"wp:attachment":[{"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/media?parent=6677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/categories?post=6677"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unknownerror.org\/index.php\/wp-json\/wp\/v2\/tags?post=6677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}