Add new XML parser example that uses a class

Author: derickr

reference/xml/examples.xml

@@ -74,23 +74,23 @@ $map_array = array(
     "LITERAL"  => "TT"
 );
 
-function startElement($parser, $name, $attrs) 
+function startElement($parser, $name, $attrs)
 {
     global $map_array;
     if (isset($map_array[$name])) {
         echo "<$map_array[$name]>";
     }
 }
 
-function endElement($parser, $name) 
+function endElement($parser, $name)
 {
     global $map_array;
     if (isset($map_array[$name])) {
         echo "</$map_array[$name]>";
     }
 }
 
-function characterData($parser, $data) 
+function characterData($parser, $data)
 {
     echo $data;
 }
@@ -140,39 +140,39 @@ xml_parser_free($xml_parser);
 <?php
 $file = "xmltest.xml";
 
-function trustedFile($file) 
+function trustedFile($file)
 {
     // only trust local files owned by ourselves
-    if (!preg_match("@^([a-z][a-z0-9+.-]*)\:\/\/@i", $file) 
+    if (!preg_match("@^([a-z][a-z0-9+.-]*)\:\/\/@i", $file)
         && fileowner($file) == getmyuid()) {
             return true;
     }
     return false;
 }
 
-function startElement($parser, $name, $attribs) 
+function startElement($parser, $name, $attribs)
 {
     echo "&lt;<font color=\"#0000cc\">$name</font>";
     if (count($attribs)) {
         foreach ($attribs as $k => $v) {
-            echo " <font color=\"#009900\">$k</font>=\"<font 
+            echo " <font color=\"#009900\">$k</font>=\"<font
                    color=\"#990000\">$v</font>\"";
         }
     }
     echo "&gt;";
 }
 
-function endElement($parser, $name) 
+function endElement($parser, $name)
 {
     echo "&lt;/<font color=\"#0000cc\">$name</font>&gt;";
 }
 
-function characterData($parser, $data) 
+function characterData($parser, $data)
 {
     echo "<b>$data</b>";
 }
 
-function PIHandler($parser, $target, $data) 
+function PIHandler($parser, $target, $data)
 {
     switch (strtolower($target)) {
         case "php":
@@ -183,20 +183,20 @@ function PIHandler($parser, $target, $data)
             if (trustedFile($parser_file[$parser])) {
                 eval($data);
             } else {
-                printf("Untrusted PHP code: <i>%s</i>", 
+                printf("Untrusted PHP code: <i>%s</i>",
                         htmlspecialchars($data));
             }
             break;
     }
 }
 
-function defaultHandler($parser, $data) 
+function defaultHandler($parser, $data)
 {
     if (substr($data, 0, 1) == "&" && substr($data, -1, 1) == ";") {
-        printf('<font color="#aa00aa">%s</font>', 
+        printf('<font color="#aa00aa">%s</font>',
                 htmlspecialchars($data));
     } else {
-        printf('<font size="-1">%s</font>', 
+        printf('<font size="-1">%s</font>',
                 htmlspecialchars($data));
     }
 }
@@ -224,7 +224,7 @@ function externalEntityRefHandler($parser, $openEntityNames, $base, $systemId,
     return false;
 }
 
-function new_xml_parser($file) 
+function new_xml_parser($file)
 {
     global $parser_file;
 
@@ -235,7 +235,7 @@ function new_xml_parser($file)
     xml_set_processing_instruction_handler($xml_parser, "PIHandler");
     xml_set_default_handler($xml_parser, "defaultHandler");
     xml_set_external_entity_ref_handler($xml_parser, "externalEntityRefHandler");
-    
+
     if (!($fp = @fopen($file, "r"))) {
         return false;
     }
@@ -323,6 +323,86 @@ xml_parser_free($xml_parser);
    </example>
   </para>
  </section>
+
+ <section xml:id="example.xml-parsing-with-class">
+  <title>XML Parsing With Class</title>
+  <para>
+   This example shows how to use a class with handlers.
+   <example>
+    <title>Show XML Element Structure</title>
+    <programlisting role="php">
+<![CDATA[
+<?php
+$file = "examples/book.xml";
+
+class CustomXMLParser
+{
+    private $fp;
+    private $parser;
+    private $depth = 0;
+
+    function __construct(string $file)
+    {
+        if (!($this->fp = fopen($file, 'r'))) {
+            throw new RunTimeException("could not open XML file '{$file}'");
+        }
+
+        $this->parser = xml_parser_create();
+
+        xml_set_element_handler($this->parser, self::startElement(...), self::endElement(...));
+        xml_set_character_data_handler($this->parser, self::cdata(...));
+    }
+
+    private function startElement($parser, $name, $attrs)
+    {
+        for ($i = 0; $i < $this->depth; $i++) {
+            echo "  ";
+        }
+        echo "$name\n";
+        $this->depth++;
+    }
+
+    private function endElement($parser, $name)
+    {
+        $this->depth--;
+    }
+
+    private function cdata($parse, $cdata)
+    {
+        if (trim($cdata) === '') {
+            return;
+        }
+        for ($i = 0; $i < $this->depth; $i++) {
+            echo "  ";
+        }
+        echo trim($cdata), "\n";
+    }
+
+    public function parse()
+    {
+        while ($data = fread($this->fp, 4096)) {
+            if (!xml_parse($this->parser, $data, feof($this->fp))) {
+                throw new RunTimeException(
+                    sprintf(
+                        "XML error: %s at line %d",
+                        xml_error_string(xml_get_error_code($this->parser)),
+                        xml_get_current_line_number($this->parser)
+                    )
+                );
+            }
+        }
+    }
+}
+
+$xmlParser = new CustomXMLParser($file);
+$xmlParser->parse();
+?>
+]]>
+    </programlisting>
+   </example>
+  </para>
+ </section>
+
 </chapter>
 
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