What is the best way to export and import theme options?

1 comment

1. I’m just about done adding my own admin panel class an Import/ Export functionality and I’ve come to a point where i feel the best way to export data would be as a base64 encoded serialize array, and this is way,

   serialize data alone is somewhat human readable and i wonted to avoid that (theme options have stored files,images url , paths and other sensitive data), hence the base64 encoding.

   Now i agree this makes a mess of a data but a simple single line string comes out which is very easy to copy paste without making mistakes (like removing lines, brackets, parentheses …).

   As for the size of $_GET depends on used browser. Some support 2000 character,
   some more. I have a rule of thumb to use $_POST method, if send data has more than
   255 character.

   Example , say $options is an array of theme options then export is done like this

   echo "<!*!* START export Code !*!*>n".base64_encode(serialize($options))."n<!*!* END export Code !*!*>";
   

   and the import code is:

   $import_code = $_POST['import_code'];
   $import_code = str_replace("<!*!* START export Code !*!*>n","",$import_code);
   $import_code = str_replace("n<!*!* END export Code !*!*>","",$import_code);
   $import_code = base64_decode($import_code);
   $import_code = unserialize($import_code);
   

   this is actually the code i use in my plugin Shortcodes UI for the import export functionality.

   Update

   As for downloading the export dump, you don’t have to create a more the one request meaning that you can export to a file with a single request, ex:

   //first  add a new query var
   public function add_query_var_vars() {
       global $wp;
       $wp->add_query_var('theme_export_options');
   }
   
   //then add a template redirect which looks for that query var and if found calls the download function
   public function admin_redirect_download_files(){
       global $wp;
       global $wp_query;
       //download theme export
       if (array_key_exists('theme_export_options', $wp->query_vars) && $wp->query_vars['theme_export_options'] == 'safe_download'){
           download_file();
           die();
       }
   }
   
   
   //add hooks for these functions
   add_action('template_redirect', 'admin_redirect_download_files');
   add_filter('init', 'add_query_var_vars');
   
   
   //then define the function that will take care of the actual download
   public function download_file($content = null, $file_name = null){
       if (! wp_verify_nonce($_REQUEST['nonce'], 'theme_export_options') ) 
           wp_die('Security check'); 
   
       //here you get the options to export and set it as content, ex:
       $options= get_option('my_theme_options');
       $content = "<!*!* START export Code !*!*>n".base64_encode(serialize($options))."n<!*!* END export Code !*!*>";
       $file_name = 'theme_export.txt';
       header('HTTP/1.1 200 OK');
   
   
       if ( !current_user_can('edit_themes') )
           wp_die('<p>'.__('You do not have sufficient permissions to edit templates for this site.').'</p>');
       }
       if ($content === null || $file_name === null){
           wp_die('<p>'.__('Error Downloading file.').'</p>');     
       }
       $fsize = strlen($content);
       header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
       header('Content-Description: File Transfer');
       header("Content-Disposition: attachment; filename=" . $file_name);
       header("Content-Length: ".$fsize);
       header("Expires: 0");
       header("Pragma: public");
       echo $content;
       exit;
   }
   
   
   //and last a simple function to create the download export url / link
   function create_export_download_link($echo = false){
       $site_url = get_bloginfo('url');
       $args = array(
           'theme_export_options' => 'safe_download',
           'nonce' => wp_create_nonce('theme_export_options')
       );
       $export_url = add_query_arg($args, $site_url);
       if ($echo === true)
           echo '<a href="'.$export_url.'" target="_blank">Download Export</a>';
       elseif ($echo == 'url')
           return $export_url;
       return '<a href="'.$export_url.'" target="_blank">Download Export</a>';
   }
   

   So all i have to do is add a call to create_export_download_link(true); in my theme options panel and it will create a link like this :

   <a href="http://domain.com/?theme_export_options=safe_download&nonce=as4d56as4" target="_blank">Download Export</a>
   

   obviously you will need to change it up a bit to match your needs but you should get the idea.

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