add an interface to Feed, stub some additional feed types

ATOM.php

@@ -1,38 +1,4 @@
 <?php
 namespace FeedWriter;
-
-/*
- * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
- *
- * This file is part of the "Universal Feed Writer" project.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/**
- * Wrapper for creating ATOM feeds
- *
- * @package     UniversalFeedWriter
- */
-class Atom extends Feed
-{
-	/**
-	* {@inheritdoc}
-	*/
-	function __construct()
-	{
-		parent::__construct(Feed::ATOM);
-	}
-
-}
+use \FeedWriter\View\Atom as NewAtom;
+class ATOM extends NewAtom { }

Item.php

@@ -2,6 +2,7 @@
 namespace FeedWriter;
 
 use \DateTime;
+use \FeedWriter\View\SyndicationBase;
 
 /*
  * Copyright (C) 2008 Anis uddin Ahmad <anisniit@gmail.com>
@@ -26,7 +27,7 @@ use \DateTime;
 /**
  * Universal Feed Writer
  *
- * Item class - Used as feed element in Feed class
+ * Item class - Used as feed element in SyndicationBase class
  *
  * @package         UniversalFeedWriter
  * @author          Anis uddin Ahmad <anisniit@gmail.com>
@@ -54,7 +55,7 @@ class Item
 	*
 	* @param    constant     (RSS1/RSS2/ATOM) RSS2 is default.
 	*/
-	function __construct($version = Feed::RSS2)
+	function __construct($version = SyndicationBase::RSS2)
 	{
 		$this->version = $version;
 	}
@@ -136,7 +137,7 @@ class Item
 	* Return the type of this feed item
 	*
 	* @access   public
-	* @return   string  The feed type, as defined in Feed.php
+	* @return   string  The feed type, as defined in SyndicationBase.php
 	*/
 	public function getVersion()
 	{
@@ -154,7 +155,7 @@ class Item
 	*/
 	public function setDescription($description)
 	{
-		$tag = ($this->version == Feed::ATOM) ? 'summary' : 'description';
+		$tag = ($this->version == SyndicationBase::ATOM) ? 'summary' : 'description';
 		return $this->addElement($tag, $description);
 	}
 
@@ -168,8 +169,8 @@ class Item
 	 */
 	public function setContent($content)
 	{
-		if ($this->version != Feed::ATOM)
-			die('The content element is supported in ATOM feeds only.');
+		if ($this->version != SyndicationBase::ATOM)
+			throw new Exception('The content element is supported in ATOM feeds only.');
 
 		return $this->addElement('content', $content, array('type' => 'html'));
 	}
@@ -209,18 +210,18 @@ class Item
 				$date = strtotime($date);
 
 				if ($date === FALSE)
-					die('The given date string was not parseable.');
+					throw new Exception('The given date string was not parseable.');
 			}
 		}
 		else if ($date < 0)
-			die('The given date is not an UNIX timestamp.');
+			throw new Exception('The given date is not an UNIX timestamp.');
 
-		if($this->version == Feed::ATOM)
+		if($this->version == SyndicationBase::ATOM)
 		{
 			$tag    = 'updated';
 			$value  = date(\DATE_ATOM, $date);
 		}
-		elseif($this->version == Feed::RSS2)
+		elseif($this->version == SyndicationBase::RSS2)
 		{
 			$tag    = 'pubDate';
 			$value  = date(\DATE_RSS, $date);
@@ -243,14 +244,14 @@ class Item
 	*/
 	public function setLink($link)
 	{
-		if($this->version == Feed::RSS2 || $this->version == Feed::RSS1)
+		if($this->version == SyndicationBase::RSS2 || $this->version == SyndicationBase::RSS1)
 		{
 			$this->addElement('link', $link);
 		}
 		else
 		{
 			$this->addElement('link','',array('href'=>$link));
-			$this->addElement('id', Feed::uuid($link,'urn:uuid:'));
+			$this->addElement('id', SyndicationBase::uuid($link,'urn:uuid:'));
 		}
 
 		return $this;
@@ -275,21 +276,21 @@ class Item
 	*/
 	public function addEnclosure($url, $length, $type, $multiple = TRUE)
 	{
-		if ($this->version == Feed::RSS1)
-			die('Media attachment is not supported in RSS1 feeds.');
+		if ($this->version == SyndicationBase::RSS1)
+			throw new Exception('Media attachment is not supported in RSS1 feeds.');
 
 		// the length parameter should be set to 0 if it can't be determined
 		// see http://www.rssboard.org/rss-profile#element-channel-item-enclosure
 		if (!is_numeric($length) || $length < 0)
-			die('The length parameter must be an integer and greater or equals to zero.');
+			throw new Exception('The length parameter must be an integer and greater or equals to zero.');
 
 		// Regex used from RFC 4287, page 41
 		if (!is_string($type) || preg_match('/.+\/.+/', $type) != 1)
-			die('type parameter must be a string and a MIME type.');
+			throw new Exception('type parameter must be a string and a MIME type.');
 
 		$attributes = array('length' => $length, 'type' => $type);
 
-		if ($this->version == Feed::RSS2)
+		if ($this->version == SyndicationBase::RSS2)
 		{
 			$attributes['url'] = $url;
 			$this->addElement('enclosure', '', $attributes, FALSE, $multiple);
@@ -334,15 +335,15 @@ class Item
 	{
 		switch($this->version)
 		{
-			case Feed::RSS1: die('The author element is not supported in RSS1 feeds.');
+			case SyndicationBase::RSS1: throw new Exception('The author element is not supported in RSS1 feeds.');
 				break;
-			case Feed::RSS2:
+			case SyndicationBase::RSS2:
 				if ($email != null)
 					$author = $email . ' (' . $author . ')';
 
 				$this->addElement('author', $author);
 				break;
-			case Feed::ATOM:
+			case SyndicationBase::ATOM:
 				$elements = array('name' => $author);
 
 				// Regex from RFC 4287 page 41
@@ -369,21 +370,21 @@ class Item
 	*/
 	public function setId($id, $permaLink = false)
 	{
-		if ($this->version == Feed::RSS2)
+		if ($this->version == SyndicationBase::RSS2)
 		{
 			if (!is_bool($permaLink))
-				die('The permaLink parameter must be boolean.');
+				throw new Exception('The permaLink parameter must be boolean.');
 
 			$permaLink = $permaLink ? 'true' : 'false';
 
 			$this->addElement('guid', $id, array('isPermaLink' => $permaLink));
 		}
-		else if ($this->version == Feed::ATOM)
+		else if ($this->version == SyndicationBase::ATOM)
 		{
-			$this->addElement('id', Feed::uuid($id,'urn:uuid:'), NULL, TRUE);
+			$this->addElement('id', SyndicationBase::uuid($id,'urn:uuid:'), NULL, TRUE);
 		}
 		else
-			die('A unique ID is not supported in RSS1 feeds.');
+			throw new Exception('A unique ID is not supported in RSS1 feeds.');
 
 		return $this;
 	}

README

@@ -1,20 +1,33 @@
-This package can be used to generate feeds in either RSS 1.0, RSS 2.0 or ATOM
-formats.
+FeedWriter
+==========
 
-There are three main classes that abstract the feed information and another to
-encapsulate the feed items information.
+This package can be used to generate feeds in a number of formats, including
+RSS 1.0, RSS 2.0, and Atom.
 
-Applications can create feed writer object, several feed item objects, set
-several types of properties of either feeds and feed items, and add items to
-the feed.
+Each output format is handled by a member of the `FeedWriter\View` namespace.
+These offer an interface for setting properties of feeds, creating individual
+feed items, and manipulating items directly.
 
-Once a feed is fully composed with its items, the feed writer class can generate
-the necessary XML structure to describe the feed in the RSS or ATOM formats.
-The feed is generated as part of the current feed output.
+In addition to these basic facilities, the `Feed` class provides an interface
+for mapping collections of items to a standard format for use by any of the
+desired views.  Users with collection of model objects may define a single
+mapping and use it to produce any view on demand.
+
+Executable sample code is provided for all views.
+
+output formats
+--------------
+
+* Atom
+* RSS 1.0
+* RSS 2.0
+* CSV
+* JSON
+* Google Product XML
 
 
 Requirements
-============
+------------
 
 PHP >= 5.3
 
@@ -23,14 +36,15 @@ PHP >= 5.0 in the "legacy-php-5.0" branch.
 
 
 Documentation
-=============
+-------------
 
 The documentation can be found in the "gh-pages" branch or on GitHub Pages:
 http://mibe.github.io/FeedWriter/
 
 
 Authors
-=======
+-------
+
 (in chronological order)
 
 Anis uddin Ahmad

RSS1.php

@@ -1,37 +1,4 @@
 <?php
 namespace FeedWriter;
-
-/* 
- * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
- *
- * This file is part of the "Universal Feed Writer" project.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/**
- * Wrapper for creating RSS1 feeds
- *
- * @package     UniversalFeedWriter
- */
-class RSS1 extends Feed
-{
-	/**
-	* {@inheritdoc}
-	*/
-	function __construct()
-	{
-		parent::__construct(Feed::RSS1);
-	}
-}
+use \FeedWriter\View\RSS1 as NewRSS1;
+class RSS1 extends NewRSS1 { }

RSS2.php

@@ -1,37 +1,4 @@
 <?php
 namespace FeedWriter;
-
-/*
- * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
- *
- * This file is part of the "Universal Feed Writer" project.
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-/**
- * Wrapper for creating RSS2 feeds
- *
- * @package     UniversalFeedWriter
- */
-class RSS2 extends Feed
-{
-	/**
-	* {@inheritdoc}
-	*/
-	function __construct()
-	{
-		parent::__construct(Feed::RSS2);
-	}
-}
+use \FeedWriter\View\RSS2 as NewRSS2;
+class RSS2 extends NewRSS2 { }

View/Atom.php

@@ -0,0 +1,67 @@
+<?php
+namespace FeedWriter\View;
+
+use FeedWriter\View\SyndicationBase;
+
+/*
+ * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
+ *
+ * This file is part of the "Universal Feed Writer" project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Wrapper for creating ATOM feeds
+ *
+ * @package     UniversalFeedWriter
+ */
+class Atom extends SyndicationBase
+{
+  public $require = [
+    'date',
+    'author',
+    'content',
+    'title',
+    'link',
+  ];
+
+	/**
+	* {@inheritdoc}
+	*/
+	function __construct()
+	{
+		parent::__construct(SyndicationBase::ATOM);
+	}
+
+  public function collect ($source_item)
+  {
+    $item = $this->createNewItem();
+
+    $item->setTitle($source_item->title);
+    $item->setLink($source_item->link);
+    $item->setDate($source_item->date);
+    $item->setAuthor($source_item->author);
+
+    // TODO:  Hrm.
+    // $item->setEnclosure('http://upload.wikimedia.org/wikipedia/commons/4/49/En-us-hello-1.ogg', 11779, 'audio/ogg');
+
+    // Internally changed to "summary" tag for ATOM feed:
+    $item->setDescription('This is a test of adding CDATA encoded description by the php <b>Universal Feed Writer</b> class');
+    $item->setContent($source_item->content);
+
+    $this->addItem($item);
+  }
+
+}

View/CSV.php

@@ -0,0 +1,24 @@
+<?php
+namespace FeedWriter\View;
+
+use \SparkLib\CSV as SparkCSV;
+
+class CSV {
+
+  public function __construct ()
+  {
+    $this->_csv = new SparkCSV();
+    $this->_csv->addHeader(['date', 'author']);
+  }
+
+  public function collect ($item)
+  {
+    $this->_csv->addRow([$item->date, $item->author]);
+  }
+
+  public function generateFeed ()
+  {
+    return $this->_csv->render();
+  }
+
+}

View/JSON.php

@@ -0,0 +1,23 @@
+<?php
+namespace FeedWriter\View;
+
+class JSON {
+
+  public $require = ['date', 'author'];
+
+  protected $_struct = [];
+
+  public function collect ($item)
+  {
+    $this->_struct[] = [
+      'date'   => $item->date,
+      'author' => $item->author
+    ];
+  }
+
+  public function generateFeed ()
+  {
+    return json_encode($this->_struct);
+  }
+
+}

View/RSS1.php

@@ -0,0 +1,39 @@
+<?php
+namespace FeedWriter\View;
+
+use FeedWriter\View\SyndicationBase;
+
+/* 
+ * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
+ *
+ * This file is part of the "Universal Feed Writer" project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Wrapper for creating RSS1 feeds
+ *
+ * @package     UniversalFeedWriter
+ */
+class RSS1 extends SyndicationBase
+{
+	/**
+	* {@inheritdoc}
+	*/
+	function __construct()
+	{
+		parent::__construct(SyndicationBase::RSS1);
+	}
+}

View/RSS2.php

@@ -0,0 +1,39 @@
+<?php
+namespace FeedWriter;
+
+use FeedWriter\View\SyndicationBase;
+
+/*
+ * Copyright (C) 2012 Michael Bemmerl <mail@mx-server.de>
+ *
+ * This file is part of the "Universal Feed Writer" project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Wrapper for creating RSS2 feeds
+ *
+ * @package     UniversalFeedWriter
+ */
+class RSS2 extends SyndicationBase
+{
+	/**
+	* {@inheritdoc}
+	*/
+	function __construct()
+	{
+		parent::__construct(Feed::RSS2);
+	}
+}

View/SyndicationBase.php

@@ -0,0 +1,856 @@
+<?php
+namespace FeedWriter\View;
+
+use \DateTime;
+use \FeedWriter\Item;
+
+/*
+ * Copyright (C) 2008 Anis uddin Ahmad <anisniit@gmail.com>
+ * Copyright (C) 2010-2013 Michael Bemmerl <mail@mx-server.de>
+ *
+ * This file is part of the "Universal Feed Writer" project.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// RSS 0.90  Officially obsoleted by 1.0
+// RSS 0.91, 0.92, 0.93 and 0.94  Officially obsoleted by 2.0
+// So, define constants for RSS 1.0, RSS 2.0 and ATOM
+
+/**
+ * Universal Feed Writer class
+ *
+ * Generate RSS 1.0, RSS2.0 and ATOM Feeds
+ *
+ * @package     UniversalFeedWriter
+ * @author      Anis uddin Ahmad <anisniit@gmail.com>
+ * @link        http://www.ajaxray.com/projects/rss
+ */
+abstract class SyndicationBase
+{
+	const RSS1 = 'RSS 1.0';
+	const RSS2 = 'RSS 2.0';
+	const ATOM = 'ATOM';
+
+	/**
+	* Collection of all channel elements
+	*/
+	private $channels      = array();
+
+	/**
+	* Collection of items as object of \FeedWriter\Item class.
+	*/
+	private $items         = array();
+
+	/**
+	* Store some other version wise data
+	*/
+	private $data          = array();
+
+	/**
+	* The tag names which have to encoded as CDATA
+	*/
+	private $CDATAEncoding = array();
+
+	/**
+	* Collection of XML namespaces
+	*/
+	private $namespaces    = array();
+
+	/**
+	* Contains the format of this feed.
+	*/
+	private $version   = null;
+
+	/**
+	* Constructor
+	*
+	* If no version is given, a feed in RSS 2.0 format will be generated.
+	*
+	* @param    constant    the version constant (RSS1/RSS2/ATOM).
+	*/
+	protected function __construct($version = self::RSS2)
+	{
+		$this->version = $version;
+
+		// Setting default value for essential channel elements
+		$this->channels['title'] = $version . ' Feed';
+		$this->channels['link']  = 'http://www.ajaxray.com/blog';
+
+		// Add some default XML namespaces
+		$this->namespaces['content'] = 'http://purl.org/rss/1.0/modules/content/';
+		$this->namespaces['wfw'] = 'http://wellformedweb.org/CommentAPI/';
+		$this->namespaces['atom'] = 'http://www.w3.org/2005/Atom';
+		$this->namespaces['rdf'] = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
+		$this->namespaces['rss1'] = 'http://purl.org/rss/1.0/';
+		$this->namespaces['dc'] = 'http://purl.org/dc/elements/1.1/';
+		$this->namespaces['sy'] = 'http://purl.org/rss/1.0/modules/syndication/';
+
+		//Tag names to encode in CDATA
+		$this->CDATAEncoding = array('description', 'content:encoded', 'summary');
+	}
+
+	// Start # public functions ---------------------------------------------
+
+	/**
+	* Adds a channel element indicating the program used to generate the feed.
+	*
+	* @return   void
+	*/
+	public function addGenerator()
+	{
+		if ($this->version == static::ATOM)
+			$this->setChannelElement('atom:generator', 'FeedWriter', array('uri' => 'https://github.com/mibe/FeedWriter'));
+		else if ($this->version == static::RSS2)
+			$this->setChannelElement('generator', 'FeedWriter');
+		else
+			throw new Exception('The generator element is not supported in RSS1 feeds.');
+
+		return $this;
+	}
+
+	/**
+	* Add a XML namespace to the internal list of namespaces. After that,
+	* custom channel elements can be used properly to generate a valid feed.
+	*
+	* @access   public
+	* @param    string  namespace prefix
+	* @param    string  namespace name (URI)
+	* @return   void
+	* @link     http://www.w3.org/TR/REC-xml-names/
+	*/
+	public function addNamespace($prefix, $uri)
+	{
+		$this->namespaces[$prefix] = $uri;
+		return $this;
+	}
+
+	/**
+	* Add a channel element to the feed.
+	*
+	* @access   public
+	* @param    string  name of the channel tag
+	* @param    string  content of the channel tag
+	* @param    bool    TRUE if this element can appear multiple times
+	* @return   void
+	*/
+	public function setChannelElement($elementName, $content, $multiple = false)
+	{
+		if ($multiple === TRUE)
+			$this->channels[$elementName][] = $content;
+		else
+			$this->channels[$elementName] = $content;
+
+		return $this;
+	}
+
+	/**
+	* Set multiple channel elements from an array. Array elements
+	* should be 'channelName' => 'channelContent' format.
+	*
+	* @access   public
+	* @param    array   array of channels
+	* @return   void
+	*/
+	public function setChannelElementsFromArray($elementArray)
+	{
+		if (!is_array($elementArray))
+			return;
+
+		foreach ($elementArray as $elementName => $content)
+		{
+			$this->setChannelElement($elementName, $content);
+		}
+
+		return $this;
+	}
+
+	/**
+	* Get the appropriate MIME type string for the current feed.
+	*
+	* @access public
+	* @return string
+	*/
+	public function getMIMEType()
+	{
+		switch($this->version)
+		{
+			case static::RSS2 : $mimeType = "application/rss+xml";
+				break;
+			case static::RSS1 : $mimeType = "application/rdf+xml";
+				break;
+			case static::ATOM : $mimeType = "application/atom+xml";
+				break;
+			default : $mimeType = "text/xml";
+		}
+
+		return $mimeType;
+	}
+
+	/**
+	* Print the actual RSS/ATOM file
+	*
+	* Sets a Content-Type header and echoes the contents of the feed.
+	* Should only be used in situations where direct output is desired;
+	* if you need to pass a string around, use generateFeed() instead.
+	*
+	* @access   public
+	* @param    bool  FALSE if the specific feed media type should be sent.
+	* @return   void
+	*/
+	public function printFeed($useGenericContentType = false)
+	{
+		$contentType = "text/xml";
+
+		if (!$useGenericContentType)
+		{
+			$contentType = $this->getMIMEType();
+		}
+
+		header("Content-Type: " . $contentType);
+		echo $this->generateFeed();
+	}
+
+	/**
+	* Generate the feed.
+	*
+	* @access public
+	* @return string
+	*/
+	public function generateFeed()
+	{
+		return $this->makeHeader()
+			. $this->makeChannels()
+			. $this->makeItems()
+			. $this->makeFooter();
+	}
+
+	/**
+	* Create a new Item.
+	*
+	* @access   public
+	* @return   object  instance of Item class
+	*/
+	public function createNewItem()
+	{
+		$Item = new Item($this->version);
+		return $Item;
+	}
+
+	/**
+	* Add a FeedItem to the main class
+	*
+	* @access   public
+	* @param    Item  instance of Item class
+	* @return   void
+	*/
+	public function addItem(Item $feedItem)
+	{
+		if ($feedItem->getVersion() != $this->version)
+			throw new Exception('Feed type mismatch: This instance can handle ' . $this->version . ' feeds only, but item with type ' . $feedItem->getVersion() . ' given.');
+
+		$this->items[] = $feedItem;
+
+		return $this;
+	}
+
+
+	// Wrapper functions -------------------------------------------------------------------
+
+	/**
+	* Set the 'title' channel element
+	*
+	* @access   public
+	* @param    string  value of 'title' channel tag
+	* @return   void
+	*/
+	public function setTitle($title)
+	{
+		return $this->setChannelElement('title', $title);
+	}
+
+	/**
+	* Set the date when the ATOM feed was lastly updated.
+	*
+	* This adds the 'updated' element to the feed. The value of the date parameter
+	* can be either an instance of the DateTime class, an integer containing a UNIX
+	* timestamp or a string which is parseable by PHP's 'strtotime' function.
+	*
+	* Not supported in RSS1 feeds.
+	*
+	* @access   public
+	* @param    DateTime|int|string  Date which should be used.
+	* @return   void
+	*/
+	public function setDate($date)
+	{
+		if ($this->version == static::RSS1)
+			throw new Exception('The publication date is not supported in RSS1 feeds.');
+
+		// The feeds have different date formats.
+		$format = $this->version == static::ATOM ? \DATE_ATOM : \DATE_RSS;
+
+		if ($date instanceof DateTime)
+			$date = $date->format($format);
+		else if(is_numeric($date) && $date >= 0)
+			$date = date($format, $date);
+		else if (is_string($date))
+			$date = date($format, strtotime($date));
+		else
+			throw new Exception('The given date was not an instance of DateTime, a UNIX timestamp or a date string.');
+
+		if ($this->version == static::ATOM)
+			$this->setChannelElement('updated', $date);
+		else
+			$this->setChannelElement('lastBuildDate', $date);
+
+		return $this;
+	}
+
+	/**
+	* Set the 'description' channel element
+	*
+	* @access   public
+	* @param    string  value of 'description' channel tag
+	* @return   void
+	*/
+	public function setDescription($description)
+	{
+		if ($this->version != static::ATOM)
+			$this->setChannelElement('description', $description);
+		return $this;
+	}
+
+	/**
+	* Set the 'link' channel element
+	*
+	* @access   public
+	* @param    string  value of 'link' channel tag
+	* @return   void
+	*/
+	public function setLink($link)
+	{
+		return $this->setChannelElement('link', $link);
+	}
+
+	/**
+	* Set custom 'link' channel elements.
+	*
+	* In ATOM feeds, only one link with alternate relation and the same combination of
+	* type and hreflang values.
+	*
+	* @access   public
+	* @param    string  URI of this link
+	* @param    string  relation type of the resource
+	* @param    string  media type of the target resource
+	* @param    string  language of the resource
+	* @param    string  human-readable information about the resource
+	* @param    int     length of the resource in bytes
+	* @link     https://www.iana.org/assignments/link-relations/link-relations.xml
+	* @link     https://tools.ietf.org/html/rfc4287#section-4.1.1
+	*/
+	public function setAtomLink($href, $rel = null, $type = null, $hreflang = null, $title = null, $length = null)
+	{
+		$data = array('href' => $href);
+
+		if ($rel != null)
+		{
+			if (!is_string($rel) || empty($rel))
+				throw new Exception('rel parameter must be a string and a valid relation identifier.');
+
+			$data['rel'] = $rel;
+		}
+		if ($type != null)
+		{
+			// Regex used from RFC 4287, page 41
+			if (!is_string($type) || preg_match('/.+\/.+/', $type) != 1)
+				throw new Exception('type parameter must be a string and a MIME type.');
+
+			$data['type'] = $type;
+		}
+		if ($hreflang != null)
+		{
+			// Regex used from RFC 4287, page 41
+			if (!is_string($hreflang) || preg_match('/[A-Za-z]{1,8}(-[A-Za-z0-9]{1,8})*/', $hreflang) != 1)
+				throw new Exception('hreflang parameter must be a string and a valid language code.');
+
+			$data['hreflang'] = $hreflang;
+		}
+		if ($title != null)
+		{
+			if (!is_string($title) || empty($title))
+				throw new Exception('title parameter must be a string and not empty.');
+
+			$data['title'] = $title;
+		}
+		if ($length != null)
+		{
+			if (!is_int($length) || $length < 0)
+				throw new Exception('length parameter must be a positive integer.');
+
+			$data['length'] = (string)$length;
+		}
+
+		// ATOM spec. has some restrictions on atom:link usage
+		// See RFC 4287, page 12 (4.1.1)
+		if ($this->version == static::ATOM)
+		{
+			foreach($this->channels as $key => $value)
+			{
+				if ($key != 'atom:link')
+					continue;
+
+				// $value is an array , so check every element
+				foreach($value as $linkItem)
+				{
+					// Only one link with relation alternate and same hreflang & type is allowed.
+					if (@$linkItem['rel'] == 'alternate' && @$linkItem['hreflang'] == $hreflang && @$linkItem['type'] == $type)
+						throw new Exception('The feed must not contain more than one link element with a relation of "alternate"'
+						. ' that has the same combination of type and hreflang attribute values.');
+				}
+			}
+		}
+
+		return $this->setChannelElement('atom:link', $data, true);
+	}
+
+	/**
+	* Set an 'atom:link' channel element with relation=self attribute.
+	* Needs the full URL to this feed.
+	*
+	* @link     http://www.rssboard.org/rss-profile#namespace-elements-atom-link
+	* @access   public
+	* @param    string  URL to this feed
+	* @return   void
+	*/
+	public function setSelfLink($url)
+	{
+		return $this->setAtomLink($url, 'self', $this->getMIMEType());
+	}
+
+	/**
+	* Set the 'image' channel element
+	*
+	* @access   public
+	* @param    string  title of image
+	* @param    string  link url of the image
+	* @param    string  path url of the image
+	* @return   void
+	*/
+	public function setImage($title, $link, $url)
+	{
+		return $this->setChannelElement('image', array('title'=>$title, 'link'=>$link, 'url'=>$url));
+	}
+
+	/**
+	* Set the 'about' channel element. Only for RSS 1.0
+	*
+	* @access   public
+	* @param    string  value of 'about' channel tag
+	* @return   void
+	*/
+	public function setChannelAbout($url)
+	{
+		$this->data['ChannelAbout'] = $url;
+		return $this;
+	}
+
+	/**
+	* Generate an UUID.
+	*
+	* The UUID is based on an MD5 hash. If no key is given, a unique ID as the input
+	* for the MD5 hash is generated.
+	*
+	* @author     Anis uddin Ahmad <admin@ajaxray.com>
+	* @param      string  optional key on which the UUID is generated
+	* @param      string  an optional prefix
+	* @return     string  the formated UUID
+	*/
+	public static function uuid($key = null, $prefix = '')
+	{
+		$key = ($key == null) ? uniqid(rand()) : $key;
+		$chars = md5($key);
+		$uuid  = substr($chars,0,8) . '-';
+		$uuid .= substr($chars,8,4) . '-';
+		$uuid .= substr($chars,12,4) . '-';
+		$uuid .= substr($chars,16,4) . '-';
+		$uuid .= substr($chars,20,12);
+
+		return $prefix . $uuid;
+	}
+	// End # public functions ----------------------------------------------
+
+	// Start # private functions ----------------------------------------------
+
+	/**
+	* Returns all used XML namespace prefixes in this instance.
+	* This includes all channel elements and feed items.
+	* Unfortunately some namespace prefixes are not included,
+	* because they are hardcoded, e.g. rdf.
+	*
+	* @access   private
+	* @return   array    Array with namespace prefix as value.
+	*/
+	private function getNamespacePrefixes()
+	{
+		$prefixes = array();
+
+		// Get all tag names from channel elements...
+		$tags = array_keys($this->channels);
+
+		// ... and now all names from feed items
+		foreach ($this->items as $item)
+			$tags = array_merge($tags, array_keys($item->getElements()));
+
+		// Look for prefixes in those tag names
+		foreach($tags as $tag)
+		{
+			$elements = explode(':', $tag);
+
+			if (count($elements) != 2)
+				continue;
+
+			$prefixes[] = $elements[0];
+		}
+
+		return array_unique($prefixes);
+	}
+
+	/**
+	* Returns the XML header and root element, depending on the feed type.
+	*
+	* @access   private
+	* @return   void
+	*/
+	private function makeHeader()
+	{
+		$out = '<?xml version="1.0" encoding="utf-8"?>' . PHP_EOL;
+
+		$prefixes = $this->getNamespacePrefixes();
+		$attributes = array();
+		$tagName = '';
+		$defaultNamespace = '';
+
+		if($this->version == static::RSS2)
+		{
+			$tagName = 'rss';
+			$attributes['version'] = '2.0';
+		}
+		elseif($this->version == static::RSS1)
+		{
+			$tagName = 'rdf:RDF';
+			$prefixes[] = 'rdf';
+			$defaultNamespace = $this->namespaces['rss1'];
+		}
+		else if($this->version == static::ATOM)
+		{
+			$tagName = 'feed';
+			$defaultNamespace = $this->namespaces['atom'];
+
+			// Ugly hack to remove the 'atom' value from the prefixes array.
+			$prefixes = array_flip($prefixes);
+			unset($prefixes['atom']);
+			$prefixes = array_flip($prefixes);
+		}
+
+		// Iterate through every namespace prefix and add it to the element attributes.
+		foreach($prefixes as $prefix)
+		{
+			if (!isset($this->namespaces[$prefix]))
+				throw new Exception('Unknown XML namespace prefix: \'' . $prefix . '\'. Use the addNamespace method to add support for this prefix.');
+			else
+				$attributes['xmlns:' . $prefix] = $this->namespaces[$prefix];
+		}
+
+		// Include default namepsace, if required
+		if (!empty($defaultNamespace))
+			$attributes['xmlns'] = $defaultNamespace;
+
+		$out .= $this->makeNode($tagName, '', $attributes, true);
+
+		return $out;
+	}
+
+	/**
+	* Closes the open tags at the end of file
+	*
+	* @access   private
+	* @return   void
+	*/
+	private function makeFooter()
+	{
+		if($this->version == static::RSS2)
+		{
+			return '</channel>' . PHP_EOL . '</rss>';
+		}
+		elseif($this->version == static::RSS1)
+		{
+			return '</rdf:RDF>';
+		}
+		else if($this->version == static::ATOM)
+		{
+			return '</feed>';
+		}
+	}
+
+	/**
+	* Creates a single node in XML format
+	*
+	* @access   private
+	* @param    string  name of the tag
+	* @param    mixed   tag value as string or array of nested tags in 'tagName' => 'tagValue' format
+	* @param    array   Attributes (if any) in 'attrName' => 'attrValue' format
+	* @param    string  True if the end tag should be omitted. Defaults to false.
+	* @return   string  formatted xml tag
+	*/
+	private function makeNode($tagName, $tagContent, $attributes = null, $omitEndTag = false)
+	{
+		$nodeText = '';
+		$attrText = '';
+
+		if(is_array($attributes) && count($attributes) > 0)
+		{
+			foreach ($attributes as $key => $value)
+			{
+				$value = htmlspecialchars($value);
+				$attrText .= " $key=\"$value\"";
+			}
+		}
+
+		if(is_array($tagContent) && $this->version == static::RSS1)
+		{
+			$attrText = ' rdf:parseType="Resource"';
+		}
+
+		$attrText .= (in_array($tagName, $this->CDATAEncoding) && $this->version == static::ATOM) ? ' type="html"' : '';
+		$nodeText .= "<{$tagName}{$attrText}>";
+		$nodeText .= (in_array($tagName, $this->CDATAEncoding)) ? '<![CDATA[' : '';
+
+		if(is_array($tagContent))
+		{
+			foreach ($tagContent as $key => $value)
+			{
+				$nodeText .= $this->makeNode($key, $value);
+			}
+		}
+		else
+		{
+			$nodeText .= (in_array($tagName, $this->CDATAEncoding)) ? $this->sanitizeCDATA($tagContent) : htmlspecialchars($tagContent);
+		}
+
+		$nodeText .= (in_array($tagName, $this->CDATAEncoding)) ? ']]>' : '';
+
+		if (!$omitEndTag)
+			$nodeText .= "</$tagName>";
+
+		$nodeText .= PHP_EOL;
+
+		return $nodeText;
+	}
+
+	/**
+	* Make the channels.
+	*
+	* @access   private
+	* @return   void
+	*/
+	private function makeChannels()
+	{
+		$out = '';
+
+		//Start channel tag
+		switch ($this->version)
+		{
+			case static::RSS2:
+				$out .= '<channel>' . PHP_EOL;
+				break;
+			case static::RSS1:
+				$out .= (isset($this->data['ChannelAbout']))? "<channel rdf:about=\"{$this->data['ChannelAbout']}\">" : "<channel rdf:about=\"{$this->channels['link']}\">";
+				break;
+		}
+
+		//Print Items of channel
+		foreach ($this->channels as $key => $value)
+		{
+			// ATOM feed needs some special handling
+			if ($this->version == static::ATOM)
+			{
+				// Strip all ATOM namespace prefixes from tags. Not needed here, because the ATOM namespace name is
+				// used as default namespace.
+				if (strncmp($key, 'atom', 4) == 0)
+					$key = substr($key, 5);
+
+				if ($key == 'link')
+				{
+					if (is_array($value))
+					{
+						// $value is an array containing multiple atom:link element attributes
+						foreach($value as $attributes)
+						{
+							// $attributes contains actually the node attributes, not the value.
+							$out .= $this->makeNode($key, '', $attributes);
+						}
+					}
+					else
+					{
+						// ATOM prints link element as href attribute
+						$out .= $this->makeNode($key, '', array('href' => $value));
+						//Add the id for ATOM
+						$out .= $this->makeNode('id', static::uuid($value, 'urn:uuid:'));
+					}
+				}
+				else
+					$out .= $this->makeNode($key, $value);
+			}
+			else
+			{
+				if ($key == 'atom:link')
+				{
+					// $value is an array containing multiple atom:link element attributes
+					foreach($value as $attributes)
+					{
+						// $attributes contains actually the node attributes, not the value.
+						$out .= $this->makeNode($key, '', $attributes);
+					}
+				}
+				else
+				{
+					$out .= $this->makeNode($key, $value);
+				}
+			}
+
+		}
+
+		//RSS 1.0 have special tag <rdf:Seq> with channel
+		if($this->version == static::RSS1)
+		{
+			$out .= "<items>" . PHP_EOL . "<rdf:Seq>" . PHP_EOL;
+			foreach ($this->items as $item)
+			{
+				$thisItems = $item->getElements();
+				$out .= "<rdf:li resource=\"{$thisItems['link']['content']}\"/>" . PHP_EOL;
+			}
+			$out .= "</rdf:Seq>" . PHP_EOL . "</items>" . PHP_EOL . "</channel>" . PHP_EOL;
+		}
+
+		return $out;
+	}
+
+	/**
+	* Prints formatted feed items
+	*
+	* @access   private
+	* @return   void
+	*/
+	private function makeItems()
+	{
+		$out = '';
+
+		foreach ($this->items as $item)
+		{
+			$thisItems = $item->getElements();
+
+			// the argument is printed as rdf:about attribute of item in rss 1.0
+			$out .= $this->startItem($thisItems['link']['content']);
+
+			foreach ($thisItems as $feedItem)
+			{
+				$name = $feedItem['name'];
+
+				// Strip all ATOM namespace prefixes from tags when feed is an ATOM feed.
+				// Not needed here, because the ATOM namespace name is used as default namespace.
+				if ($this->version == static::ATOM && strncmp($name, 'atom', 4) == 0)
+					$name = substr($name, 5);
+
+				$out .= $this->makeNode($name, $feedItem['content'], $feedItem['attributes']);
+			}
+			$out .= $this->endItem();
+		}
+
+		return $out;
+	}
+
+	/**
+	* Make the starting tag of channels
+	*
+	* @access   private
+	* @param    string  The vale of about tag which is used for RSS 1.0 only.
+	* @return   void
+	*/
+	private function startItem($about = false)
+	{
+		$out = '';
+
+		if($this->version == static::RSS2)
+		{
+			$out .= '<item>' . PHP_EOL;
+		}
+		else if($this->version == static::RSS1)
+		{
+			if($about)
+			{
+				$out .= "<item rdf:about=\"$about\">" . PHP_EOL;
+			}
+			else
+			{
+				throw new Exception("link element is not set - It's required for RSS 1.0 to be used as the about attribute of the item tag.");
+			}
+		}
+		else if($this->version == static::ATOM)
+		{
+			$out .= "<entry>" . PHP_EOL;
+		}
+
+		return $out;
+	}
+
+	/**
+	* Closes feed item tag
+	*
+	* @access   private
+	* @return   void
+	*/
+	private function endItem()
+	{
+		if($this->version == static::RSS2 || $this->version == static::RSS1)
+		{
+			return '</item>' . PHP_EOL;
+		}
+		else if($this->version == static::ATOM)
+		{
+			return '</entry>' . PHP_EOL;
+		}
+	}
+
+	/**
+	* Sanitizes data which will be later on returned as CDATA in the feed.
+	*
+	* A "]]>" respectively "<![CDATA" in the data would break the CDATA in the
+	* XML, so the brackets are converted to a HTML entity.
+	*
+	* @access   private
+	* @param    string  Data to be sanitized
+	* @return   string  Sanitized data
+	*/
+	private function sanitizeCDATA($text)
+	{
+		$text = str_replace("]]>", "]]&gt;", $text);
+		$text = str_replace("<![CDATA[", "&lt;![CDATA[", $text);
+
+		return $text;
+	}
+
+	// End # private functions ----------------------------------------------
+
+} // end of class Feed

examples/example_atom.php

@@ -8,7 +8,7 @@ include('../ATOM.php');
 
 date_default_timezone_set('UTC');
 
-use \FeedWriter\ATOM;
+use \FeedWriter\View\ATOM;
 
 /*
  * Copyright (C) 2008 Anis uddin Ahmad <anisniit@gmail.com>

examples/example_minimum.php

@@ -8,7 +8,7 @@ include('../RSS2.php');
 
 date_default_timezone_set('UTC');
 
-use \FeedWriter\RSS2;
+use \FeedWriter\View\RSS2;
 
 /* 
  * Copyright (C) 2008 Anis uddin Ahmad <anisniit@gmail.com>