PHP XML Classes
Path Parser (class_path_parser.php)
Downloads at Sourceforge

Description: A generic XML parsing class that lets your set-up PHP functions to be called when some XML elements are found.
Using this class you can set handlers for specific XML paths, for example /foo/data/name, for each handler you set up a PHP function in the form foo($name,$attribs,$content) that the parser will call when an element matching the given path is found by the parser.
Summarizing this is a good tool to generalize parsing tasks using SAX/expat from PHP. It can be used as a generic parsing class and is specially useful to retrieve elements from a very large file before processing each element using DOM. (We've parsed 50Mb XML documents with success using this class).

NEWS:
  • 06-20-2002 First version of this class released.
This class code as well as documentation are hosted at SourceForge please visit our SourceForge page for releases, documentation, bug-tracking, support forums and mailing lists.

Resources Requirements
  • PHP 4.0.5+

Features To-dos
  • Absolute paths can be parsed.
  • Multiple handlers can be set, a handler can handle multiple paths.
  • Namespaces are supported (local name can be used regardless of the namespace)
  • Support for paths with wildcards is planned example //name or /foo//name

Contact: Luis Argerich (lrargerich@yahoo.com)

Detailed description and usage:

See path_parser.php for an example about how to use the class, this is the code: 

include_once("class_path_parser.php");

function name($name,$attribs,$content) {
  print("
");
  print("Hey $name 
\n");
  print_r($attribs);
  print("
");
}

$parser = new Path_parser();
$parser->set_handler("/foo/data/name","name");
$parser->set_handler("/foo/data","name");
$parser->set_handler("/foo/data/type/var","name");
if(!$parser->parse_file("foo.xml")) {
  print("Error:".$parser->get_error()."
\n"); 
}


As you can see using this class is very easy and can provide a lot of very good results. If the document uses namespaces you can set-up paths based on local-names. (A handler setting paths using qualified names is planned for a future release)

Documentation

Classes

Path_parser

Extends: None
Description: Using this class you can parse an XML file setting handlers for specific XML elements defined by paths, for example /foo/data/name or /foo/data, the handlers can receive the element name, attributes and content. This class can be used in several ways incresing XML processing felxibility a lot.

Method Summary
 string get_error()
          Returns last error message
 void init()
          Initializes the parser
 boolean parse_file(string $xml)
          Parses an XML document from a file or URL
 boolean parse(string $data, boolean $is_final)
          Parses data
 void set_handler(string $path, string $handler_name)
          Sets a handler to process XML elements
 

Method Detail

get_error

string get_error()
This function can be used to return last error message when something went wrong.
 
Parameters:
Returns:
The error message
Throws:
None

init

void init()
This method must be called if you plan to parse more than one document using the same object, after parsing a document call init and you are ready to parse a new document.
 
Parameters:
Returns:
Nothing
Throws:
None

parse_file

boolean parse_file(string $xml)
This method can be used to parse an XML document from a file or URL
 
Parameters:
$xml - URI or name of the file containing the document to be parsed
Returns:
True if the document was parsed succesfully, false if there was some error.
Throws:
If an error occurss this method sets an error message that can be recovered with get_error

parse

boolean parse(string $data, boolean $is_final)
This is a generic parsing method it can be used to parse chunks of data.
 
Parameters:
$data - This should contain a chunk of XML data to be parsed
$is_final - This is a boolean var indicating if the chunk passed as the previous argument was the last chunk of data to be parsed by the parser
Returns:
True if the data was parsed succesfully or false if there was some error
Throws:
None

set_handler

void set_handler(string $path, string $handler_name)
This method can be used to process XML elements that match a given pattern, for example /foo or /foo/name or /foo/data/name, etc. You set-up the name of a PHP function to be called when the element is parsed.
 
Parameters:
$path - This is an absolute path from the roor of the XML document for example /foo/data/name will match name elements children of data children of foo (foo is the root element).
$handler_name - The handler must receive the following arguments: $name,$attribs and $content. $name will be the name of the element. $attribs is an array of asocs containing the element attributes and $content will be a string with the element content (text and subelements)
Returns:
Nothing
Throws:
None