Building + Consuming WebServices CF Style Kevin Penny MMCP (4.5/5/MX6)

Topics Covered Uses of Web Services Advantages of Web Services Web Service Diagram Languages of Web Services Creating Web Services Accessing Web Services Securing Web Services Best Practices References

Uses - Web Services in Action Remotely lookup Product Inventory on Vendor overseas on the Web Create a stock lookup that’s available to a Flash Mobile application Create an interface to an already existing application to share data internally with other systems at a company Time Card System that may ‘check-in’ / ‘check-out’ employees in one area of the company maintained at another Central Location. Search Term / Search Results interface (i.e. Google) Others??

Advantages – Old vs. New Old Method Form post of an xml file or specific value(s) as a name/value to a url The url receives the post and expects a certain ‘name(s)’ as input Processes the input and creates an XML document that the two parties agree on Response is a text/xml document that the sender receives back and parses and processes the response from the XML document. No Soap No WSDL No UDDI Limited New Method –(Web Services) Cfc created in Cold Fusion Function (method) created to ‘do’ something Parameters can be passed to function as arguments WSDL file is Generated automatically SOAP message created and accepted automatically Returnvalue specifies the value of the response.

Advantages (con’t) STANDARDS BASED - all speaking the same language that’s Industry Standard Network/Language/System Neutral – Can be implemented in many different languages behind the scenes, but can be made accessible via web services. WSDL File - describes what’s needed in a readable XML format that tells developers what to call, what to pass in, and what’s expected (if anything) Self Documenting – Write the code and the Documentation at the same time. Publicly Available (optionally) - Can be made publicly available in a web service directory as an API (application programming interface) to your application or a part of your application (see References area for UDDI) REUSE - you do not have to recreate application logic that someone else has already created and, therefore, you can build your applications faster

Example – Ask Geeves…(ripoff )Ask Geeves Form Post Web Service Call Web Service Output CFAdministrator setup WSDL FileWSDL ColdFusion Component Explorer for generated WSDL FileColdFusion Component

Languages - Your Web Service Toolkit You’ll need your… –XML (eXtensible Markup Language) ** –WSDL (Web Services Definition Language) * –SOAP (Simple Object Access Protocol) –UDDI (Universal Description, Discovery, and Integration) –Implementation Language of Choice ** ColdFusion/.Net/Flash/Java etc… –Familiarity with Structures and Arrays is a plus –** Denotes Most Important in the ToolKit for CF Developers

Diagram - Path of the Web Service

Creating Web Services The CFC Creation – The CFFunction Method/Function – The Access Method – The return ‘Datatype’ – The Code in the cffunction –business logic/database lookup/logging/tracking/permissions The CFRETURN value

Accessing Web Services Cfinvoke webservice= * –url to wsdl file on external server –Can be setup in CF Admin (just like a datasource) –Arguments can be passed to the web service as or inline (name/value pairs) –Method = xyz The ‘function’ you want to access –Createobject() inside a cfscript to invoke a webservice –Cfobject tag to call a webservice All options give the same performance * deontes my preference

Securing Your Web Services Providing Access to your Web Service –Methods Login/Password Reference Key Encrypted Keys Cfid/cftokens Jsessions etc IP Restrictions Bottom Line: however you would secure your website, you can secure your Web Service

Best Practices KISS Principle – Basic datatypes are preferred to complex datatypes –i.e. Strings compared to CFusion Queries Test before you publish + error trap – –if the cfc works prior to publishing it, it should work afterwards Caching can/may occur –be prepared for it Get familiar with One way of creating/consuming web services and use it (personal preference)

References ColdFusion Web Services – Beginners GuideBeginners Guide Googles Web Search API – XMethods.com – CFDOCS Online/LocalLocal UDDI Registry –IBMIBM “The Pragmatic Programmer”The Pragmatic Programmer –Book of the Month