QueryPath is a PHP library designed for working with HTML and XML, akin to jQuery but server-side. It simplifies complex tasks related to document manipulation and integration with web services, providing a compact and mnemonic API that allows users to import, create, and query data efficiently. Used in environments like Drupal and various web services, it enhances the capabilities of semantic databases and content management systems.

1. QueryPath
For Web Services and Mash-ups

2. • Who created it?
• What does it do?
• Where is it being used?
• Why use it?
• How is it used?

3. Matt Butcher
Maintainer of QueryPath and
the Drupal QueryPath module
http://technosophos.com
http://twitter.com/technosophos

4. 2009
2004

5. What is QueryPath?
QueryPath is a library for working with
HTML and XML in PHP.
It is like jQuery for the Server.

6. Why Another XML
Library?

7. The Task
Find all
<a></a>
tags who have
the ancestor
<div></div>

8. The DOM API
• At least seventeen
classes, each with dozens
of methods.
• Complex data structure.
• Checkered history in
PHP.
• VERY powerful.

9. SimpleXML
• One class, about a dozen
functions and methods.
• Turns XML into basic
objects.
• Makes easy stuff easy,
and makes everything
else insanely hard.
Same size as DOM
Example

10. SAX / Expat
Same size,
fewer features
• Event based.
• Write your own parser
handler.
• One per XML format.
• Only reliable “legacy”
library.

11. QueryPath
• Compact library.
• Functions are short and
mnemonic.
[This space intentionally left blank ]
• The power of DOM, but
simpler than SimpleXML
• (Shhh... don’t tell, but it’s
built on the DOM.)

12. Use it to...
• Import HTML files • Create HTML on the fly
• Read XML files • Retrieve database
content and insert it
• Work with remote web into XML or HTML
services
• Examine RDFa data
• Manipulate SVG images inside HTML or XHTML
• Retrieve RSS and Atom • Run SPARQL queries
feed data and retrieve SemWeb
content

13. Where is it Used?

14. Importing Content
• 6,000+ existing
documents
• Fragments of HTML 2,
3, and 4
• Much of it non-standard
• Imported into Drupal
using BatchAPI, Tidy, and
QueryPath

15. Querying Semantic
Information
• Use the OpenAmplify
web service
• Submit node content
• Use results to enrich
page
• Build a supermashup
(seven web services)
http://www.youtube.com/watch?v=GBBKPIva1tM

16. Gateway to Web
Services
• 100’s of Gigabytes of
data
• Stored in an external
Digital Asset
Management tool
• XML gateway
• QueryPath integrates
Drupal with the DAM

17. Semantic Network
• DBPedia is semantic
equivalent of Wikipedia
• Query with SPARQL
• Return semantically
oriented XML content
• QueryPath can query
and make use of the
results

18. Twitter Mash-up
• Retrieve latest posts
from Twitter
• Submit them to
OpenAmplify for analysis
• Provide “ratings” and
sentiment information
• Not in Drupal
http://tweetypants.com

19. Frameweld Framework
• Frameweld uses
QueryPath as part of
their proprietary
framework
• Clean separation of
presentation and other
logic
• QueryPath translates
data objects into HTML Frameweld contributes
back to QueryPath

20. Why Use It?

21. Shorten Difficult Tasks
<?php
require 'QueryPath/QueryPath.php';
$odt = 'zip://o.odt#content.xml';
foreach(qp($odt, 'text|h') as $i) {
print $i->text() . "n";
}
(Prints an outline from an ODT document)

22. Twitter Search
Ten Lines of Code

23. How is it Used?

24. A Closer Look
‣Object-oriented
‣Operates on files, strings, or streams
‣Uses CSS 3 Selectors
‣Has dozens of methods

25. The Features
• Query a document • Access remote data
• With XPath • Extensions for...
• CSS selectors • XSLT, XSD, PI
• Move around inside the • SQL database access
document
• Templates
• Modify the document
• Access local files

26. Traversing an
HTML or XML
Document
There are over a dozen
functions for traversing a
document.
These are similar to jQuery’s
traversal functions.

27. Manipulating a
Document
• Get and set text,
elements,
attributes, etc.
• Move, clone,
delete.
• Build arbitrary
XML or HTML.

28. In Drupal...
• Install the
QueryPath
module
• Begin using
QueryPath in
your modules

29. Outside of Drupal
• Go to
QueryPath.org
• Download
QueryPath
• Use it in your
applications

30. Learn More
• IBM DeveloperWorks published an
introduction to QueryPath:
http://is.gd/2wHPA
• The full API docs are available at
http://api.querypath.org
• Learn more about Drupal modules at
http://dupal.org/project/querypath