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Harnessing Web ServicesWith PHP

Geoff PetersPHP Vancouver Conference

Jan. 23, 2004

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What are Web Services Emerging standards Allow service applications to be

accessible across the web to client (non-human) applications

Example: Incorporating a web-based mapping service into your pizza delivery application.

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Pizza Application Example

MappingDatabase Internet

PizzaDelivery

Application

Web Services

Thanks, Web Services!

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Some Uses of Web Services Business to Business (B2B)

communication Online storefronts Syndication of News Feeds

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Examples of Web Services Amazon.com (Storefronts) Google.com (Google API) Microsoft (MSDN, Terraservice,

Mappoint, .NET Alerts) Bioinformatics (EMBL Nucleotide

Sequence Database, BQS) AllConsuming.Net Weblogs.com, Technorati.com, and

Alexa.com

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Problem of Information Fragmentation Information is scattered in thousands

of different databases/resources Currently, each resource (or group)

must be manually accessed Growth of available information sources

Each resource has its own proprietary way to access it!

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Need for Common Standards Web Services standards

will allow information from diverse sources to be collected and combined in new ways

Future of the Internet More integrated, useful, smarter,

customizable.

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Case Study: Google.com Google provides Web Services access

to its search engine (“Google API”). Allows programmers to retrieve

search results using code. “Developer’s Program” encourages

creativity Limits each user to 1000

searches/day

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GoogleDuel.com An online popularity ranking system. Uses Google’s API to obtain

estimated count of search results for each term.

Example:1. coke (1,010,000)

2. pepsi (633,000)

How about PHP vs ASP?

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PHP Wins!

GoogleDuel results:1. PHP (86,600,000)2. ASP (78,200,000)

Good news for the PHP community!

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Uses of GoogleDuel.com Business can analyze their web

presence Compare popularity of company

name, product lines, brands, CEO, slogans with competitors

Use over time can show trends such as growing popularity of a product

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GoogleDuel for Writers GoogleDuel as a tool for writers

Helps decide what phrase or word to use:

Compare similar words or phrases Use with a thesaurus to check

popularity of a phrase “Writers” version of GoogleDuel

allows comparison of up to 10 phrases at once.

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GoogleDuel Ultra More sophisticated ranking system. Ranks for a list of adjectives. Examples:

Britney Spears is more popular, but is she more creative or talented?

Which grocery chain has the best service?

Try it at http://www.googleduel.com

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Other Uses of Google API Gender Guesser

Searches for common patterns involving a first name.

Calculates likelihood person is male or female.

Calculates popularity of name. Works for ethnic names (ex. “Naveen”) Saves data and produces reports, ex:

“Most Popular Names” “Most Feminine Names”

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Demos (if time) GoogleDuel

http://www.googleduel.com

Gender Guesser http://cgi.sfu.ca/~gpeters/cgi-bin/

pear/gender.php

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Technical Side Some current Web Services standards: SOAP (Simple Object Access Protocol)

XML based protocol, works over HTTP. Allows variables to be passed to/from a

remote procedure call. Parameter format defined in a WSDL document

Adopted by Microsoft (.NET), Google, Amazon.

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A competing standard to SOAP

“REST” – “Representational State Transfer”

HTTP based Uses HTTP for security/authentication

Parameters encoded in URL, not in a SOAP envelope.

Returns an XML document. Some advocate it as “second

generation web services” Some sites provide REST interfaces as well as

SOAP.

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PHP Support for Web Services SOAP package in Pear library

Developed by Shane Caraveo and Arnaud Limbourg

Provides both Client and Server support Makes Web Services easy to write and

access for PHP developers. NuSOAP

An alternate library, quite popular.

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Example – Accessing Google

include("SOAP/Client.php");

$soapclient = new SOAP_Client('http://api.google.com/search/beta2');$soapoptions = array('namespace' => 'urn:GoogleSearch',

'trace' => 0);

$ret = $soapclient->call('doGoogleSearch', $params = array( 'key' => $key, 'q' => $query, 'start' => 0, 'maxResults' => 1, 'filter' =>

false, 'restrict' => '', 'safeSearch' => false, 'lr' => '', 'ie' => '', 'oe' => '',), $soapoptions);

if (PEAR::isError($ret)) { // error handling goes here

} else // We have proper search results { // Results from the Google search are stored in the object $ret. // in this example, the only thing we need from the search results // is the estimatedTotalResultsCount $num = $ret->estimatedTotalResultsCount; }

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Growth of Web Services According to IDC Research, "Web

services will become the dominant distributed computing architecture in the next 10 years and will eventually define the fabric of computing."

Reducing integration costs Service-oriented computing as

opposed to presentation-oriented

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Web Services Business Models Charge small amount per-use of

service Eventually, will Google do this?

Subscription-based services Microsoft’s Mappoint.

Use free Web Services to generate sales and interest Amazon’s storefront approach

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Other Business Models Better vertical integration

Automated information exchanges between different levels in distribution channels

Business to Business services Mobile Web Services

Web services on wireless devices / cell phones

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Advantages of Web Services Shorter Development Time

No need to “re-invent the wheel”. Libraries for web services becoming

more stable. Standardized Integration Standardized Access

Use universal HTTP protocol. Can be accessed anywhere on

Internet.

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Current Challenges Service discovery

How to locate Web Services Create a registry of web services, ex. UDDI

(Universal Description, Discovery, and Integration)

Security and reliability (authentication, encryption) Ex: Use existing protocols such as SSL with

credentials/Token Based authentication Transactions

Multiple transactions – synchronous/asynchronous Performance

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Comparing Web Services with other Distributed Models Other distributed models:

CORBA, DCOM, Java/RMI For use within a homogeneous system, or

cooperating enterprise systems. Not well suited for use over Internet.

Web Services will not replace these existing standards For use in exchange of information in a

decentralized, distributed environment. i.e. over the Internet.

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Conclusion Web services are important to the

future of the Internet (service-oriented computing).

PHP libraries make web services easy and accessible for PHP developers.

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Links Web Services Business Article (USA Today)

http://www.usatoday.com/money/industries/technology/2003-09-30-amazon_x.htm

SOAP http://www.soapware.org REST http://www.xfront.com/REST-Web-Services.html PHP Soap Server Tutorial

http://www.phppatterns.com/index.php/article/articleview/41/1/2/

PHP Soap Client Tutorial http://www.phppatterns.com/index.php/article/articleview/39/1/2/

Web Services Tutorial (By Shane Caraveo) http://talks.php.net/show/soap-phpcon-ny2003/

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Contacts Geoff Peters (SFU)

www.sfu.ca/~gpeters gpeters at sfu dot ca

Shane Caraveo (ActiveState) shane at caraveo dot com

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Thank You Questions?