Core Improvements: Next Round #79 #80

engine/Plugin/View.php

@@ -0,0 +1,227 @@
+<?php
+
+/**
+ * View class
+ */
+class View
+{
+    /**
+     * Path to view file.
+     *
+     * @var string
+     */
+    protected $view_file;
+
+    /**
+     * View variables.
+     *
+     * @var array
+     */
+    protected $vars = array();
+
+    /**
+     * Global view variables.
+     *
+     * @var array
+     */
+    protected static $global_vars = array();
+
+    /**
+     * The output.
+     *
+     * @var string
+     */
+    protected $output;
+
+    /**
+     * Create a new view object.
+     *
+     *  <code>
+     *      // Create new view object
+     *      $view = new View('blog/views/backend/index');
+     *
+     *      // Assign some new variables
+     *      $view->assign('msg', 'Some message...');
+     *
+     *      // Get view
+     *      $output = $view->render();
+     *
+     *      // Display view
+     *      echo $output;
+     *  </code>
+     *
+     * @param string $view      Name of the view file
+     * @param array  $variables Array of view variables
+     */
+    public function __construct($view, array $variables = array())
+    {
+        // Set view file
+        // From current theme folder or from plugin folder
+        if (File::exists($theme_view_file = THEMES_SITE . DS . Site::theme() . DS . $view . '.view.php') && BACKEND == false) {
+            $this->view_file = $theme_view_file;
+        } else {
+            $this->view_file = PLUGINS . DS . $view . '.view.php';
+        }
+
+        // Is view file exists ?
+        if (file_exists($this->view_file) === false) {
+            throw new RuntimeException(vsprintf("%s(): The '%s' view does not exist.", array(__METHOD__, $view)));
+        }
+
+        // Set view variables
+        $this->vars = $variables;
+    }
+
+    /**
+     * View factory
+     *
+     *  <code>
+     *      // Create new view object, assign some variables
+     *      // and displays the rendered view in the browser.
+     *      View::factory('blog/views/backend/index')
+     *          ->assign('msg', 'Some message...')
+     *          ->display();
+     *  </code>
+     *
+     * @param  string $view      Name of the view file
+     * @param  array  $variables Array of view variables
+     * @return View
+     */
+    public static function factory($view, array $variables = array())
+    {
+        return new View($view, $variables);
+    }
+
+    /**
+     * Assign a view variable.
+     *
+     *  <code>
+     *      $view->assign('msg', 'Some message...');
+     *  </code>
+     *
+     * @param  string  $key    Variable name
+     * @param  mixed   $value  Variable value
+     * @param  boolean $global Set variable available in all views
+     * @return View
+     */
+    public function assign($key, $value, $global = false)
+    {
+        // Assign a new view variable (global or locale)
+        if ($global === false) {
+            $this->vars[$key] = $value;
+        } else {
+            View::$global_vars[$key] = $value;
+        }
+
+        return $this;
+    }
+
+    /**
+     * Include the view file and extracts the view variables before returning the generated output.
+     *
+     *  <code>
+     *      // Get view
+     *      $output = $view->render();
+     *
+     *      // Display output
+     *      echo $output;
+     *  </code>
+     *
+     * @param  string $filter Callback function used to filter output
+     * @return string
+     */
+    public function render($filter = null)
+    {
+        // Is output empty ?
+        if (empty($this->output)) {
+
+            // Extract variables as references
+            extract(array_merge($this->vars, View::$global_vars), EXTR_REFS);
+
+            // Turn on output buffering
+            ob_start();
+
+            // Include view file
+            include($this->view_file);
+
+            // Output...
+            $this->output = ob_get_clean();
+        }
+
+        // Filter output ?
+        if ($filter !== null) {
+            $this->output = call_user_func($filter, $this->output);
+        }
+
+        // Return output
+        return $this->output;
+    }
+
+    /**
+     * Displays the rendered view in the browser.
+     *
+     *  <code>
+     *      $view->display();
+     *  </code>
+     *
+     */
+    public function display()
+    {
+        echo $this->render();
+    }
+
+    /**
+     * Magic setter method that assigns a view variable.
+     *
+     * @param string $key   Variable name
+     * @param mixed  $value Variable value
+     */
+    public function __set($key, $value)
+    {
+        $this->vars[$key] = $value;
+    }
+
+    /**
+     * Magic getter method that returns a view variable.
+     *
+     * @param  string $key Variable name
+     * @return mixed
+     */
+    public function __get($key)
+    {
+        if (isset($this->vars[$key])) {
+            return $this->vars[$key];
+        }
+    }
+
+    /**
+     * Magic isset method that checks if a view variable is set.
+     *
+     * @param  string  $key Variable name
+     * @return boolean
+     */
+    public function __isset($key)
+    {
+        return isset($this->vars[$key]);
+    }
+
+    /**
+     * Magic unset method that unsets a view variable.
+     *
+     * @param string $key Variable name
+     */
+    public function __unset($key)
+    {
+        unset($this->vars[$key]);
+    }
+
+    /**
+     * Method that magically converts the view object into a string.
+     *
+     * @return string
+     */
+    public function __toString()
+    {
+        return $this->render();
+    }
+}