[opw-web] Optimize skin variables and localization

[Owen Taylor <otaylor src gnome org>]

commit d04e4ab14e2e593439552a7d1bee697442b57668
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Fri Apr 4 12:16:44 2014 -0400

    Optimize skin variables and localization
    
     * use preg_replace_callback() to avoid searching through text
       for each variable or (worse) each localized string.
     * Don't include the file of localized strings *each* time we
       need to localize something, instead keep it around.

 classes/class_lang.php |  125 ++++++++++++++++++++++++++----------------------
 classes/class_skin.php |   20 +++++---
 2 files changed, 80 insertions(+), 65 deletions(-)
---
diff --git a/classes/class_lang.php b/classes/class_lang.php
index 99ff8ec..d54c461 100644
--- a/classes/class_lang.php
+++ b/classes/class_lang.php
@@ -14,16 +14,34 @@ class lang
     // Constructor
     function __construct()
     {
-        global $config;
+        global $config, $core;
 
         $this->lang_name = $config->lang_name;
-        $this->lang_vars = array();
+        $this->lang_vars = null;
+        $this->lang_data = null;
     }
 
-    // Function to parse localization data
-    function parse($data)
+    function _init_lang_vars()
     {
-        global $core, $user, $gsod, $config;
+        global $core, $config, $user;
+
+        if ($this->lang_vars !== null)
+            return;
+
+        $this->lang_vars = array(
+            'host' => htmlspecialchars($core->base_uri()),
+            'site_name' => htmlspecialchars($config->site_name),
+            'username' => htmlspecialchars($user->username),
+            'timezone' => htmlspecialchars(date('T'))
+        );
+    }
+
+    function _load()
+    {
+        global $config;
+
+        if ($this->lang_data !== null)
+            return;
 
         if (file_exists(realpath("lang/{$this->lang_name}.php")))
         {
@@ -37,49 +55,60 @@ class lang
             $gsod->trigger($title, $message);
         }
 
-        $data = $this->set_defaults($data);
-
-        foreach ($lang_data as $key => $value)
-        {
-            $value = $this->parse_vars($value);
-            $data = str_replace("{{{$key}}}", $value, $data);
-        }
-
-        // Show unlocalized data as is
-        $data = preg_replace('/\{\{(.*?)\}\}/', '$1', $data);
+        // Add default values
+        $lang_data['lang_name'] = $this->lang_name;
+        $lang_data['site_name'] = $config->site_name;
+        $lang_data['site_copyright'] = $config->site_copyright;
 
-        // Done!
-        return $data;
+        $this->lang_data = $lang_data;
     }
 
-    // Parses language variables
-    function parse_vars($data)
+    function _replace($matches)
     {
-        global $config, $core, $user;
+        $k = $matches[1];
+        if (isset($this->lang_data[$k]))
+            return $this->parse_vars($this->lang_data[$k]);
+        else
+            return $k;
+    }
 
-        // Substitute generic data within the laguage files
-        $data = str_replace("[[host]]", htmlspecialchars($core->base_uri()), $data);
-        $data = str_replace("[[site_name]]", $config->site_name, $data);
-        $data = str_replace("[[username]]", htmlspecialchars($user->username), $data);
-        $data = str_replace("[[timezone]]", htmlspecialchars(date('T')), $data);
+    // Function to parse localization data
+    function parse($data)
+    {
+        global $core, $user, $gsod, $config;
 
-        // Replace placeholder with values
-        foreach ($this->lang_vars as $key => $value)
-        {
-            $data = str_replace("[[$key]]", $value, $data);
-        }
+        $this->_load();
+        $this->_init_lang_vars();
 
-        // Remove unknown placeholders
-        $data = preg_replace('/\[\[(.*?)\]\]/', '', $data);
+        // Replace localized strings; unknown strings are left as is
+        return preg_replace_callback('/\{\{(.*?)\}\}/',
+                                     array($this, '_replace'),
+                                     $data);
+    }
 
-        // Done!
-        return $data;
+    function _replace_var($matches)
+    {
+        $k = $matches[1];
+        if (isset($this->lang_vars[$k]))
+            return $this->lang_vars[$k];
+        else
+            // Remove unknown placeholders
+            return '';
     }
 
+    // Parses language variables
+    function parse_vars($data)
+    {
+        return preg_replace_callback('/\[\[(.*?)\]\]/',
+                                     array($this, '_replace_var'),
+                                     $data);
+    }
 
     // Function to assign language variables
     function assign($data, $value = "")
     {
+        $this->_init_lang_vars();
+
         if (!is_array($data) && $value)
         {
             $this->lang_vars[$data] = $value;
@@ -98,26 +127,11 @@ class lang
     {
         global $config, $core, $user;
 
-        // Return default data
-        switch ($key)
-        {
-            case 'lang_name':
-                return $this->lang_name;
-            case 'site_name':
-                return $config->site_name;
-            case 'site_copyright':
-                return $config->site_copyright;
-        }
-
-        // Get language data from lang file
-        if (file_exists(realpath('lang/' . $this->lang_name . '.php')))
-        {
-            include('lang/' . $this->lang_name . '.php');
-        }
+        $this->_load();
 
-        if (isset($lang_data[$key]))
+        if (isset($this->lang_data[$key]))
         {
-            $data = $lang_data[$key];
+            $data = $this->lang_data[$key];
 
             // Parse placeholders
             $data = $this->parse_vars($data);
@@ -132,15 +146,10 @@ class lang
     }
 
     // Function to assign default variables
-    function set_defaults($data)
+    function get_defaults()
     {
         global $config;
 
-        $data = str_replace("{{lang_name}}", $this->lang_name, $data);
-        $data = str_replace("{{site_name}}", $config->site_name, $data);
-        $data = str_replace("{{site_copyright}}", $config->site_copyright, $data);
-
-        return $data;
     }
 
     // Function to exclude a string from being treated as a key
diff --git a/classes/class_skin.php b/classes/class_skin.php
index 733fdee..ab216f6 100644
--- a/classes/class_skin.php
+++ b/classes/class_skin.php
@@ -63,6 +63,16 @@ class skin
         $this->skin_title = $value;
     }
 
+    function _replace_skin_var($matches)
+    {
+        $k = $matches[1];
+        if (isset($this->skin_vars[$matches[1]]))
+            return $this->skin_vars[$matches[1]];
+        else
+            // Remove unknown placeholders
+            return '';
+    }
+
     // Function to parse template variables
     function parse($file_name)
     {
@@ -95,13 +105,9 @@ class skin
         $data = file_get_contents($file_name);
 
         // Parse the skin vars
-        foreach ($this->skin_vars as $key => $value)
-        {
-            $data = str_replace("[[$key]]", $value, $data);
-        }
-
-        // Remove unknown placeholders
-        $data = preg_replace('/\[\[(.*?)\]\]/', '', $data);
+        $data = preg_replace_callback('/\[\[(.*?)\]\]/',
+                                      array($this, '_replace_skin_var'),
+                                      $data);
 
         // Remove line breaks and tabs
         $data = preg_replace('/[\n]+/', '', $data);