meta/Meta/Base/Page.php

<?php
/**
 * meta
 *
 * Hierarchial data tool
 *
 * @package		meta
 * @author 		Timothy J. Warren
 * @copyright	Copyright (c) 2012 - 2015
 * @link 		https://github.com/aviat4ion/meta
 * @license 	http://philsturgeon.co.uk/code/dbad-license
 */

// --------------------------------------------------------------------------

namespace Meta\Base;

/**
 * Class for building pages
 *
 * All methods are chainable, with the exception of the constructor,
 * build_header(), build_footer(), and _headers() methods.
 */
class Page {

	/**
	 * Meta tags
	 *
	 * @var string
	 */
	private $meta;

	/**
	 * JS tags for the header
	 *
	 * @var string
	 */
	private $head_js;

	/**
	 * JS tags for the footer
	 *
	 * @var string
	 */
	private $foot_js;

	/**
	 * CSS tags for the page
	 *
	 * @var string
	 */
	private $css;

	/**
	 * Page title
	 *
	 * @var string
	 */
	private $title;

	/**
	 * Additional header tags
	 *
	 * @var string
	 */
	private $head_tags;

	/**
	 * Class(es) to apply to the main body tag
	 *
	 * @var string
	 */
	private $body_class;

	/**
	 * Id to apply to the body tag
	 *
	 * @var string
	 */
	private $body_id;

	/**
	 * Base tag
	 *
	 * @var string
	 */
	private $base;

	/**
	 * Content for outputting
	 *
	 * @var string
	 */
	private $buffer;

	/**
	 * HTTP headers to send
	 *
	 * @var array
	 */
	private $headers;

	/**
	 * Set up the page class
	 *
	 * @return void
	 */
	public function __construct()
	{
		$this->meta       = "";
		$this->head_js    = "";
		$this->foot_js    = "";
		$this->css        = "";
		$this->title      = "";
		$this->head_tags  = "";
		$this->body_class = "";
		$this->body_id    = "";
		$this->base       = "";
		$this->buffer = "";
		$this->headers = array();
	}

	// --------------------------------------------------------------------------

	/**
	 * PHP magic method called when ending the script
	 * Used for outputing HTML
	 *
	 * @return void
	 */
	public function __destruct()
	{
		if (headers_sent())
		{
			die();
		}

		if ( ! empty($this->headers))
		{
			// Set headers
			foreach($this->headers as $key => $val)
			{
				if ( ! isset($val))
				{
					@header($key);
				}
				else
				{
					@header("$key: $val");
				}
			}
		}

		if ( ! empty($this->buffer))
		{
			(GZ_COMPRESS) ? ob_start('ob_gzhandler') : ob_start();

			echo $this->buffer;

			// Check if a buffer exists
			// so that it doesn't throw a notice
			if (ob_get_level() > 0)
			{
				ob_end_flush();
			}
		}
	}


	// --------------------------------------------------------------------------

	/**
	 * Sets server headers and doctype
	 *
	 * Also sets page mime type, based on if sent as
	 * html or xhtml, and what the target browser
	 * supports
	 *
	 * @param bool $html5
	 * @return Page
	 */
	private function _headers($html5)
	{
		$this->set_header("Cache-Control", "must-revalidate, public");
		$mime = "";

		//Variable for accept keyword
		$accept = ( ! empty($_SERVER['HTTP_ACCEPT'])) ? $_SERVER['HTTP_ACCEPT'] : "";

		//Predefine doctype
		$doctype_string = ($html5 == TRUE) ? '<!DOCTYPE html>' : '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN">';

		//Predefine charset
		$charset = "UTF-8";

		$mime = "text/html";

		if ($html5 == FALSE)
		{
			$doctype_string = '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">';
		}

		$doctype_string .= "<html lang='en'>";

		// finally, output the mime type and prolog type
		$this->set_header("Content-Type", "{$mime};charset={$charset}");
		$this->set_header("X-UA-Compatible", "chrome=1, IE=edge");
		$this->set_output($doctype_string);

		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Set Meta
	 *
	 * Sets meta tags, with codeigniter native meta tag helper
	 *
	 * @param array $meta
	 * @return Page
	 */
	public function set_meta($meta)
	{
		$this->meta .= $this->_meta($meta);
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets minified javascript group in header
	 *
	 * @param string $group
	 * @param bool $debug
	 * @return Page
	 */
	public function set_head_js_group($group, $debug = FALSE)
	{
		if ($group === FALSE)
		{
			return $this;
		}

		$file = SCRIPT_PATH . $group;
		$file .= ($debug == TRUE) ? "/debug/1" : "";
		$this->head_js .= $this->script_tag($file, FALSE);
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets a minified css group
	 * @param string $group
	 * @return Page
	 */
	public function set_css_group($group)
	{
		$link = array(
			'href' => STYLE_PATH . $group,
			'rel' => 'stylesheet',
			'type' => 'text/css'
		);
		$this->css .= $this->_link_tag($link);

		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets a minified javascript group for the page footer
	 *
	 * @param string $group
	 * @param bool $debug
	 * @return Page
	 */
	public function set_foot_js_group($group, $debug = FALSE)
	{
		$file = SCRIPT_PATH . $group;
		$file .= ($debug == TRUE) ? "/debug/1" : "";
		$this->foot_js .= $this->script_tag($file, FALSE);
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets html title string
	 *
	 * @param string $title
	 * @return Page
	 */
	public function set_title($title = "")
	{
		$title = ($title == "") ? DEFAULT_TITLE : $title;

		$this->title = $title;

		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets custom body class
	 *
	 * @param string $class
	 * @return Page
	 */
	public function set_body_class($class = "")
	{
		$this->body_class = $class;
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets custom body id
	 *
	 * @param string $id
	 * @return Page
	 */
	public function set_body_id($id = "")
	{
		$this->body_id = $id;
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets custom base href
	 *
	 * @param string href
	 * @return Page
	 */
	public function set_base($href)
	{
		$this->base = $href;
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets custom css tags
	 *
	 * @param string $name
	 * @param bool $domain
	 * @param string $media
	 * @return Page
	 */
	public function set_css_tag($name, $domain = TRUE, $media = "all")
	{
		$path     = CONTENT_DOMAIN;
		$css_file = "{$path}/css/{$name}.css";

		if ($domain == FALSE)
		{
			$css_file = $name;
		}

		$this->css_tags .= $this->_link_tag(array(
			'rel' => 'stylesheet',
			'type' => 'text/css',
			'media' => $media,
			'href' => $css_file,
		));

		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets a custom tag in the header
	 *
	 * @param string $tag
	 * @return Page
	 */
	public function set_head_tag($tag)
	{
		$this->head_tags .= $tag;
		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets custom page header
	 *
	 * @param bool $html5
	 * @return Page
	 */
	public function build_header($html5 = TRUE)
	{
		$data = array();

		//Set Meta Tags
		$this->meta   = ($html5 == TRUE)
			? '<meta charset="utf-8" />'. $this->meta
			: $this->_meta(array(
				'http-equiv' => 'Content-Type',
				'content' => 'text/html; charset=utf-8',
			)) . $this->meta;

		$data['meta'] = $this->meta;

		//Set CSS
		if ($this->css !== "")
		{
			$data['css'] = $this->css;
		}
		else
		{
			//Set default CSS group
			$this->set_css_group(DEFAULT_CSS_GROUP);
			$data['css'] = $this->css;
		}

		//Set head javascript
		$data['head_js'] = ( ! empty($this->head_js)) ? $this->head_js : "";

		//Set Page Title
		$data['title'] = ($this->title !== '') ? $this->title : DEFAULT_TITLE;

		//Set Body Class
		$data['body_class'] = $this->body_class;

		//Set Body Id
		$data['body_id'] = $this->body_id;

		//Set Base HREF
		$data['base'] = $this->base;

		//Set individual head tags
		$data['head_tags'] = $this->head_tags;

		//Set Server Headers and Doctype
		$this->_headers($html5);

		//Output Header
		$this->append_output($this->load_view('header', $data, TRUE));

		return $this;
	}

	// --------------------------------------------------------------------------

	/**
	 * Builds common footer with any additional js
	 */
	public function build_footer()
	{
		$data = array();

		$data['foot_js'] = ($this->foot_js != "") ? $this->foot_js : '';

		$this->append_output($this->load_view('footer', $data, TRUE));
	}

	// --------------------------------------------------------------------------

	/**
	 * Script Tag
	 *
	 * Helper function for making script tags
	 *
	 * @param string $js
	 * @param bool $domain
	 * @return string
	 */
	private function script_tag($js, $domain = TRUE)
	{
		$path    = CONTENT_DOMAIN;
		$js_file = "{$path}/js/{$js}.js";

		if ($domain == FALSE)
		{
			$js_file = $js;
		}

		$tag = '<script src="' . $js_file . '"></script>';

		return $tag;
	}

	// --------------------------------------------------------------------------

	/**
	 * Set Message
	 *
	 * Adds a message to the page
	 * @param string $type
	 * @param string $message
	 * @param bool $return
	 * @return void
	 */
	public function set_message($type, $message, $return=FALSE)
	{
		$data['stat_class'] = $type;
		$data['message']    = $message;

		return $this->load_view('message', $data, $return);
	}

	// --------------------------------------------------------------------------

	/**
	 * Redirect 303
	 *
	 * Shortcut function for 303 redirect
	 * @param string $url
	 */
	public function redirect_303($url)
	{
		$this->set_header("HTTP/1.1 303 See Other");
		$this->set_header("Location:" . $url);
	}

	// --------------------------------------------------------------------------

	/**
	 * Render
	 *
	 * Shortcut function for building a page
	 * @param string $view
	 * @param array $data
	 */
	public function render($view, $data=array())
	{
		$this->build_header();
		$this->load_view($view, $data);
		$this->set_foot_js_group('js');
		$this->build_footer();
	}

	// --------------------------------------------------------------------------

	/**
	 * Render Message
	 *
	 * Render a full page message
	 * @param string $type
	 * @param string $message
	 */
	public function render_message($type, $message)
	{
		$this->render('message', [
			'stat_class' => $type,
			'message' => $message
		]);
	}

	// --------------------------------------------------------------------------

	/**
	 * Output String
	 *
	 * Similar to render(), this is a shortcut
	 * to output a string in the body of the
	 * page.
	 * @param string $string
	 */
	public function output_string($string)
	{
		$this->build_header();
		$this->append_output($string);
		$this->build_footer();
	}

	// --------------------------------------------------------------------------

	/**
	 * Private helper function to generate meta tags
	 *
	 * @param array $params
	 * @return string
	 */
	private function _meta($params)
	{
		$string = "<meta ";

		foreach ($params as $k => &$v)
		{
			$string .= $k.'="'.$v.'" ';
		}

		$string .= " />";

		return $string;
	}

	// --------------------------------------------------------------------------

	/**
	 * Private helper function to generate link tags
	 *
	 * @param array $params
	 * @return string
	 */
	private function _link_tag($params)
	{
		$string = "<link ";

		foreach ($params as $k => &$v)
		{
			$string .= $k . '="'.$v.'" ';
		}

		$string .= "/>";

		return $string;
	}

	// --------------------------------------------------------------------------

	/**
	 * Function for loading a view
	 *
	 * @param string $file
	 * @param array $data
	 * @param bool $return
	 * @return mixed
	 */
	public function load_view($file, array $data=array(), $return=FALSE)
	{
		$path = MM_APP_PATH . "views/{$file}.php";

		// Contain the content for buffering
		ob_start();

		// Extract the data array
		extract($data);

		// Include the file
		include($path);

		$buffer = ob_get_contents();
		ob_end_clean();

		if ($return == TRUE)
		{
			return $buffer;
		}
		else
		{
			$this->append_output($buffer);
		}
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets a header for later output
	 *
	 * @param string $key
	 * @param string $val
	 */
	public function set_header($key, $val)
	{
		$this->headers[$key] = $val;
	}

	// --------------------------------------------------------------------------

	/**
	 * Adds text to the output buffer
	 *
	 * @param string $string
	 */
	public function append_output($string)
	{
		$this->buffer .= $string;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sets the output buffer
	 *
	 * @param string $string
	 */
	public function set_output($string)
	{
		$this->buffer = $string;
	}

	// --------------------------------------------------------------------------

	/**
	 * Sends headers and then removes them
	 */
	public function flush_headers()
	{
		// Set headers
		foreach ($this->headers as $key => $val)
		{
			if ( ! isset($val))
			{
				header($key);
			}
			else
			{
				header("{$key}: {$val}");
			}
		}

		// Empty headers
		$this->headers = array();
	}
}

// End of page.php