diff --git a/BibtexbrowserTest.php b/BibtexbrowserTest.php
index 9b7a195..41391a5 100755
--- a/BibtexbrowserTest.php
+++ b/BibtexbrowserTest.php
@@ -7,6 +7,7 @@ $ phpunit BibtexbrowserTest.php
 
 With coverage:
 $ phpunit --coverage-html ./coverage BibtexbrowserTest.php
+$ XDEBUG_MODE=coverage phpunit --coverage-filter bibtexbrowser.php --coverage-html=foo.html BibtexbrowserTest.php 
 
 (be sure that xdebug is enabled: /etc/php5/cli/conf.d# ln -s ../../mods-available/xdebug.ini)
 */
@@ -748,6 +749,7 @@ class BibtexbrowserTest extends PHPUnit_Framework_TestCase {
         fseek($test_data,0);
         $db = new BibDataBase();
         $db->update_internal("inline", $test_data);
+        
         $entry=$db->getEntryByKey($key);
         $this->assertEquals($bibtex, $entry->getText());
     }
@@ -984,10 +986,396 @@ class BibtexbrowserTest extends PHPUnit_Framework_TestCase {
       
     }
     
+    public function testYearDisplay() {
+      // Create test entries
+      $entry2020 = new RawBibEntry();
+      $entry2020->setField('year', '2020');
+      $entry2020->setField('title', 'Paper 2020');
+      $entry2020->setField('author', 'Author A');
+      
+      // assert getKey
+      $this->assertEquals('97c46f8bdf428ce28cfa05cdedba2ec1', $entry2020->getKey());
+
+      $entry2019a = new RawBibEntry(); 
+      $entry2019a->setField('year', '2019');
+      $entry2019a->setField('title', 'Paper 2019 A');
+      $entry2019a->setField('author', 'Author B');
+
+      $entry2019b = new RawBibEntry();
+      $entry2019b->setField('year', '2019'); 
+      $entry2019b->setField('title', 'Paper 2019 B');
+      $entry2019b->setField('author', 'Author C');
+
+      // Create YearDisplay
+      $display = new YearDisplay();
+      
+      // Set test entries
+      $entries = array(
+          'key2020' => $entry2020,
+          'key2019a' => $entry2019a,
+          'key2019b' => $entry2019b
+      );
+      $display->setEntries($entries);
+
+      // Get year index and verify
+      $yearIndex = $display->yearIndex;
+      $this->assertEquals("2020", $yearIndex[2020]);
+
+      // Capture output
+      ob_start();
+      $display->display();
+      $output = ob_get_clean();
+
+      // Verify output contains years and titles
+      // split output by line
+      $lines = explode("\n", $output);
+      $this->assertEquals('<div  class="theader">2020</div><table class="result">', $lines[0]);
+  }
+  
+  public function testXMLPrettyPrinter() {
+    // Create sample BibTeX entry with various fields to test
+    $bibtex = "@article{test2023,
+        author = {Test Author},
+        title = {A Test Title with Special Characters: & < >}, 
+        journal = {Test Journal},
+        year = {2023},
+        volume = {1},
+        number = {2},
+        pages = {100--200}
+    }";
+
+    // Set up input stream with BibTeX content
+    $stream = fopen('php://memory', 'r+');
+    fwrite($stream, $bibtex);
+    rewind($stream);
+
+    // Create XMLPrettyPrinter and parse
+    $printer = new XMLPrettyPrinter();
+    $printer->header = false;
+    $parser = new StateBasedBibtexParser($printer);
+
+    // Capture output
+    ob_start();
+    $parser->parse($stream);
+    $output = ob_get_clean();
+
+    // Verify XML structure and content
+    $this->assertStringContainsString('<?xml version="1.0"', $output);
+    $this->assertStringContainsString('<bibfile>', $output); 
+    $this->assertStringContainsString('</bibfile>', $output);
+    
+    // Verify entry type
+    $this->assertStringContainsString('<type>article</type>', $output);
+    
+    // Verify fields are present
+    $this->assertStringContainsString('<key>author</key>', $output);
+    $this->assertStringContainsString('<value>Test Author</value>', $output);
+    
+    // Verify special characters are escaped
+    $this->assertStringContainsString('&amp;', $output);
+    $this->assertStringContainsString('&lt;', $output);
+    $this->assertStringContainsString('&gt;', $output);
+
+    fclose($stream);
+  }    
+
+  public function testBibtexDisplay() {
+    // Create test entries
+    $entry1 = new RawBibEntry();
+    $entry1->setType('article');
+    $entry1->setField('title', 'Test Title');
+    $entry1->setField('author', 'Test Author');
+    $entry1->setField('year', '2023');
+    $entry1->setField('journal', 'Test Journal');
+    
+    $entry2 = new RawBibEntry(); 
+    $entry2->setType('inproceedings');
+    $entry2->setField('title', 'Another Title with Special Chars: é');
+    $entry2->setField('author', 'Another Author');
+    $entry2->setField('year', '2022');
+    $entry2->setField('booktitle', 'Test Conference');
+
+    // Create BibtexDisplay instance
+    $display = new BibtexDisplay();
+    $display->header = false;
+    $display->setTitle('Test Export');
+    $display->setEntries(array($entry1, $entry2));
+    
+    // assert entries in $display
+    $this->assertEquals(2, count($display->entries));
+
+    // set BIBTEXBROWSER_BIBTEX_VIEW to reconstructed
+    bibtexbrowser_configure('BIBTEXBROWSER_BIBTEX_VIEW', 'reconstructed');
+
+    // Capture output
+    ob_start();
+    $display->display();
+    $output = ob_get_clean();
+
+    // Verify output contains expected elements
+    // Header comments
+    $this->assertStringContainsString('% generated by bibtexbrowser', $output);
+    $this->assertStringContainsString('% Test Export', $output);
+    $this->assertStringContainsString('% Encoding: UTF-8', $output);
+    
+    // Entry 1 content
+    $this->assertStringContainsString('@article{', $output);
+    $this->assertStringContainsString('title = {Test Title}', $output);
+    $this->assertStringContainsString('author = {Test Author}', $output);
+    $this->assertStringContainsString('year = {2023}', $output);
+    $this->assertStringContainsString('journal = {Test Journal}', $output);
+    
+    // Entry 2 content  
+    $this->assertStringContainsString('@inproceedings{', $output);
+    $this->assertStringContainsString('title = {Another Title with Special Chars: é}', $output);
+    $this->assertStringContainsString('author = {Another Author}', $output);
+    $this->assertStringContainsString('year = {2022}', $output);
+    $this->assertStringContainsString('booktitle = {Test Conference}', $output);
+    
+  }
+
+  public function testCreateBibEntryDisplay() {
+    // Test instance creation
+    $display = createBibEntryDisplay();
+    $this->assertInstanceOf('BibEntryDisplay', $display);
+    
+    // Create test entry
+    $entry = new RawBibEntry();
+    $entry->setType('article');
+    $entry->setField('title', 'Test Title');
+    $entry->setField('author', 'Test Author');
+    $entry->setField('year', '2023');
+    $entry->setField('journal', 'Test Journal');
+    $entry->setField('abstract', 'Test Abstract');
+    $entry->setField('url', 'http://example.com');
+    
+    // assertion on toString
+    $this->assertEquals('article 4a9ba73904f4f22a7b37e18750ee5454', $entry->__toString());
+
+    // Test display with entry
+    $display->setEntries(array($entry));
+    
+    // Capture output
+    ob_start();
+    $display->display();
+    $output = ob_get_clean();
+    
+    // Verify display output contains expected elements
+    $this->assertStringContainsString('Test Title', $output);
+    $this->assertStringContainsString('Test Author', $output);
+    $this->assertStringContainsString('Test Journal', $output);
+    $this->assertStringContainsString('Test Abstract', $output);
+    
+    // Test metadata generation
+    $metadata = $display->metadata();
+    $this->assertIsArray($metadata);
+
+    // Verify metadata contains essential fields
+    $foundTitle = false;
+    $foundAuthor = false;
+    foreach($metadata as $meta) {
+        if($meta[0] == 'citation_title' && $meta[1] == 'Test Title') {
+            $foundTitle = true;
+        }
+        if($meta[0] == 'citation_author' && $meta[1] == 'Author, Test') {
+            $foundAuthor = true; 
+        }
+    }
+    $this->assertTrue($foundTitle);
+    $this->assertTrue($foundAuthor);
+    
+    // Test title generation
+    $this->assertEquals('Test Title (bibtex)', $display->getTitle());
+  }
+
+  public function testParserDelegate() {
+    // Create test delegate
+    $delegate = new TestParserDelegate();
+    
+    // Create parser with delegate
+    $parser = new StateBasedBibtexParser($delegate);
+    
+    // Create test bibtex content
+    $bibtex = "@article{test2023,
+        author = {Test Author},
+        title = {Test Title},
+        journal = {Test Journal},
+        year = {2023},
+        abstract = {Test Abstract}
+    }";
+    
+    // Create memory stream with test content
+    $stream = fopen('php://memory', 'r+');
+    fwrite($stream, $bibtex);
+    rewind($stream);
     
+    // Parse the content
+    $parser->parse($stream);
     
+    // Verify event sequence
+    $expected = array(
+        'beginFile',
+        'beginEntry',
+        'setEntryType:article',
+        'setEntryKey:test2023', 
+        'setEntryField:author:Test Author',
+        'setEntryField:title:Test Title',
+        'setEntryField:journal:Test Journal', 
+        'setEntryField:year:2023',
+        'setEntryField:abstract:Test Abstract',
+        'endEntry',
+        'endFile'
+    );
+    
+    $this->assertEquals($expected, $delegate->events);
+    
+    fclose($stream);
+  }
+
+  public function testRSSDisplay() {
+    // Create test entries with various data to test RSS generation
+    $entry1 = new RawBibEntry();
+    $entry1->setType('article');
+    $entry1->setField('title', 'Test Title with Special Chars: & < >');
+    $entry1->setField('author', 'Test Author');
+    $entry1->setField('year', '2023');
+    $entry1->setField('journal', 'Test Journal');
+    $entry1->setField('abstract', 'Test Abstract with HTML <b>tags</b>');
+    $entry1->setField('url', 'http://example.com');
+    
+    $entry2 = new RawBibEntry();
+    $entry2->setType('inproceedings');
+    $entry2->setField('title', 'Another Test Title');
+    $entry2->setField('author', 'Another Author'); 
+    $entry2->setField('year', '2022');
+    $entry2->setField('booktitle', 'Test Conference');
+    
+    // Create RSSDisplay instance
+    $display = new RSSDisplay();
+    $display->header = false;
+    $display->setTitle('Test RSS Feed');
+    $display->setEntries(array($entry1, $entry2));
+    
+    // Capture output
+    ob_start();
+    $display->display();
+    $output = ob_get_clean();
+    
+    // Verify XML declaration
+    $this->assertStringContainsString('<?xml version="1.0" encoding="UTF-8"?>', $output);
+    
+    // Verify RSS structure
+    $this->assertStringContainsString('<rss version="2.0"', $output);
+    $this->assertStringContainsString('<channel>', $output);
+    $this->assertStringContainsString('<title>Test RSS Feed</title>', $output);
+    
+    // Verify entries
+    $this->assertStringContainsString('<item>', $output);
+    $this->assertStringContainsString('Test Title with Special Chars: &#38; &#60; &#62;', $output);
+    $this->assertStringContainsString('Another Test Title', $output);
+    
+    // Verify text encoding
+    $rss = $display->text2rss('Test & Text <b>bold</b> with HTML &eacute;');
+    $this->assertEquals('Test &#38; Text bold with HTML ', $rss);
+    
+    // Verify metadata handling
+    $this->assertStringContainsString('<description>', $output);
+    $this->assertStringContainsString('<link>', $output);
+    $this->assertStringContainsString('<guid', $output);
+    
+    // Verify valid XML
+    $xml = new SimpleXMLElement($output);
+    $this->assertInstanceOf('SimpleXMLElement', $xml);
+  }
+
+  public function testHTMLTemplate() {
+    // Create mock content object that implements required methods
+    $mockContent = new class {
+        public function display() {
+            echo '<div class="test-content">Test Content</div>';
+        }
+        
+        public function getTitle() {
+            return 'Test Title';
+        }
+        
+        public function metadata() {
+            return array(
+                array('description', 'Test Description'),
+                array('keywords', 'test, bibtex')
+            );
+        }
+    };
+
+    // Capture output
+    bibtexbrowser_configure('BIBTEXBROWSER_USE_PROGRESSIVE_ENHANCEMENT', true);
+    ob_start();
+    HTMLTemplate($mockContent, false);
+    $output = ob_get_clean();
+    
+    // Verify basic HTML structure
+    $this->assertStringContainsString('<!DOCTYPE html PUBLIC', $output);
+    $this->assertStringContainsString('<html xmlns="http://www.w3.org/1999/xhtml">', $output);
+    $this->assertStringContainsString('</html>', $output);
+    
+    // Verify HEAD section
+    $this->assertStringContainsString('<meta http-equiv="Content-Type" content="text/html; charset=', $output);
+    $this->assertStringContainsString('<meta name="generator" content="bibtexbrowser', $output);
+    
+    // Verify meta tags
+    $this->assertStringContainsString('<meta name="description" property="description" content="Test Description"', $output);
+    $this->assertStringContainsString('<meta name="keywords" property="keywords" content="test, bibtex"', $output);
+    
+    // Verify title
+    $this->assertStringContainsString('<title>Test Title</title>', $output);
+    
+    // Verify CSS inclusion
+    $this->assertStringContainsString('<style type="text/css">', $output);
+    
+    // Verify content display
+    $this->assertStringContainsString('<div class="test-content">Test Content</div>', $output);
+    
+    // Verify JavaScript includes when progressive enhancement enabled
+    $this->assertStringContainsString(JQUERY_URI, $output);
+    
+  }  
 } // end class
 
+// Test implementation that records events
+class TestParserDelegate extends ParserDelegate {
+  public $events = array();
+  
+  function beginFile() {
+      $this->events[] = 'beginFile';
+  }
+  
+  function endFile() {
+      $this->events[] = 'endFile'; 
+  }
+  
+  function setEntryField($key, $value) {
+      $this->events[] = "setEntryField:".trim($key).":".trim($value);
+  }
+  
+  function setEntryType($type) {
+      $this->events[] = "setEntryType:$type";
+  }
+  
+  function setEntryKey($key) {
+      $this->events[] = "setEntryKey:$key";
+  }
+  
+  function beginEntry() {
+      $this->events[] = 'beginEntry';
+  }
+  
+  function endEntry($source) {
+      $this->events[] = 'endEntry';
+  }
+  }
+
+
+
 @copy('bibtexbrowser.local.php.bak','bibtexbrowser.local.php');
 
 ?>
diff --git a/bibtexbrowser.php b/bibtexbrowser.php
index ba5796c..297c9de 100755
--- a/bibtexbrowser.php
+++ b/bibtexbrowser.php
@@ -728,7 +728,9 @@ class StateBasedBibtexParser {
   } // end function
 } // end class
 
-/** a default empty implementation of a delegate for StateBasedBibtexParser */
+/** a default empty implementation of a delegate for StateBasedBibtexParser 
+ * @codeCoverageIgnore
+*/
 class ParserDelegate {
 
   function beginFile() {}
@@ -758,18 +760,20 @@ usage:
 see snippet of [[#StateBasedBibParser]]
 */
 class XMLPrettyPrinter extends ParserDelegate {
+  var $header = true;
   function beginFile() {
-    header('Content-type: text/xml;');
+    if ($this->header) {
+      header('Content-type: text/xml;');
+    }
     print '<?xml version="1.0" encoding="'.OUTPUT_ENCODING.'"?>';
     print '<bibfile>';
   }
 
-
   function endFile() {
     print '</bibfile>';
   }
   function setEntryField($finalkey,$entryvalue) {
-    print "<data>\n<key>".$finalkey."</key>\n<value>".$entryvalue."</value>\n</data>\n";
+    print "<data>\n<key>".trim($finalkey)."</key>\n<value>".htmlspecialchars($entryvalue)."</value>\n</data>\n";
   }
 
   function setEntryType($entrytype) {
@@ -1148,6 +1152,7 @@ function s3988($s) {
 see BibEntry->formatAuthor($author)
 @deprecated
 @nodoc
+@codeCoverageIgnore
 */
 function formatAuthor() {
   die('Sorry, this function does not exist anymore, however, you can simply use $bibentry->formatAuthor($author) instead.');
@@ -1191,7 +1196,7 @@ class BibEntry {
   var $timestamp;
 
   /** The name of the file containing this entry */
-  var $filename;
+  var $filename = "nofilename-frommemory";
 
   /** The short name of the entry (parameterized by ABBRV_TYPE) */
   var $abbrv;
@@ -1231,7 +1236,9 @@ class BibEntry {
   /** Returns the type of this bib entry (always lowercase). */
   function getType() {
     // strtolower is important to be case-insensitive
-    return strtolower($this->getField(Q_INNER_TYPE));
+    $res = $this->getField(Q_INNER_TYPE);
+    if ($res == NULL) return 'unknown';
+    return strtolower($res);
   }
 
   /** Sets the key of this bib entry. */
@@ -1467,6 +1474,10 @@ class BibEntry {
 
   /** Returns the key of this entry */
   function getKey() {
+    if ($this->getField(Q_KEY) == null) {
+      $key = md5($this->getTitle().$this->getFormattedAuthorsString());
+      $this->setField(Q_KEY, $key);
+    }
     return $this->getField(Q_KEY);
   }
 
@@ -2071,6 +2082,7 @@ class BibEntry {
 } // end class BibEntry
 
 class RawBibEntry extends BibEntry {
+
   function setField($name, $value) {
     $this->fields[$name]=$value;
     $this->raw_fields[$name]=$value;
@@ -3168,6 +3180,7 @@ class YearDisplay {
 
   /** is an array of strings representing years */
   var $yearIndex;
+  var $entries;
 
   function setDB($bibdatabase) {
     $this->setEntries($bibdatabase->bibdb);
@@ -4303,11 +4316,13 @@ usage:
       getTitle()
  * $title: title of the page
  */
-function HTMLTemplate($content) {
+function HTMLTemplate($content, $header = true) {
 
 // when we load a page with AJAX
 // the HTTP header is taken into account, not the <meta http-equiv>
-header('Content-type: text/html; charset='.OUTPUT_ENCODING);
+if ($header) {
+  header('Content-type: text/html; charset='.OUTPUT_ENCODING);
+}
 echo '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">'."\n";
 
 ?>
@@ -4406,7 +4421,9 @@ usage:
 </pre>
 */
 class BibtexDisplay {
-
+  var $header = true;
+  var $entries;
+  var $title;
   function __construct() {}
 
   function setTitle($title) { $this->title = $title; return $this; }
@@ -4419,7 +4436,9 @@ class BibtexDisplay {
   function setWrapper($x) { $x->wrapper = 'NoWrapper'; }
 
   function display() {
-    header('Content-type: text/plain; charset='.OUTPUT_ENCODING);
+    if ($this->header) {
+      header('Content-type: text/plain; charset='.OUTPUT_ENCODING);
+    }
     echo '% generated by bibtexbrowser <http://www.monperrus.net/martin/bibtexbrowser/>'."\n";
     echo '% '.@$this->title."\n";
     echo '% Encoding: '.OUTPUT_ENCODING."\n";
@@ -4534,7 +4553,8 @@ usage:
 class RSSDisplay {
 
   var $title = 'RSS produced by bibtexbrowser';
-
+  var $header = true;
+  var $entries;
   function __construct() {
     // nothing by default
   }
@@ -4558,6 +4578,7 @@ class RSSDisplay {
 
     // be careful of <
     $desc = str_replace('<','&#60;',$desc);
+    $desc = str_replace('>','&#62;',$desc);
 
     // final test with encoding:
     if (function_exists('mb_check_encoding')) { // (PHP 4 >= 4.4.3, PHP 5 >= 5.1.3)
@@ -4577,7 +4598,9 @@ class RSSDisplay {
   function setWrapper($x) { $x->wrapper = 'NoWrapper'; }
 
   function display() {
-    header('Content-type: application/rss+xml');
+    if ($this->header) {
+      header('Content-type: application/rss+xml');
+    }
     echo '<?xml version="1.0" encoding="'.OUTPUT_ENCODING.'"?>';
 //
 
@@ -4585,8 +4608,8 @@ class RSSDisplay {
 <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">
    <channel>
       <title><?php echo $this->title;?></title>
-      <link>http://<?php echo @$_SERVER['HTTP_HOST'].htmlentities(@$_SERVER['REQUEST_URI']);?></link>
-      <atom:link href="http://<?php echo @$_SERVER['HTTP_HOST'].htmlentities(@$_SERVER['REQUEST_URI']);?>" rel="self" type="application/rss+xml" />
+      <link>http://<?php echo getServerData('HTTP_HOST').htmlentities(getServerData('REQUEST_URI'));?></link>
+      <atom:link href="http://<?php echo getServerData('HTTP_HOST').htmlentities(getServerData('REQUEST_URI'));?>" rel="self" type="application/rss+xml" />
       <description></description>
       <generator>bibtexbrowser v__GITHUB__</generator>
 
@@ -4613,6 +4636,16 @@ class RSSDisplay {
   }
 }
 
+/**
+ * workaround deprecation 
+ */
+function getServerData($key) {
+  // if exists
+  if (isset($_SERVER[$key])) {
+    return $_SERVER[$key];
+  }
+  return "";
+}
 
 
 /** is responsible for transforming a query string of $_GET[..] into a publication list.