Why SOAP Services Are Being Put to REST
SOAP is now an aging protocol and its days are numbered. With so many developers familiar with the protocol and so many standards surrounding it, why are we seeing it disappear? The nail in the coffin is the mobile revolution and its driving need for web-based APIs.
While REST has been a viable service-oriented architecture (SOA) alternative for a long time, RESTful web services have really hit their stride in the last several years. Their simplicity and flexibility have always made RESTful services a great option. Yet, the appropriate use of the HTTP protocol and ability to support JSON as a transport is what has made them the preferred web service approach for the programmable web.
For a comprehensive overview of the differences between SOAP and REST, read this Enterprise Strategies piece. Mobile apps are most useful when they provide access on-the-go into online resources. For companies, this has necessitated the need to expose APIs through web services.
RESTful services are built upon the constructs of the HTTP protocol. Since mobile devices communicate across the web which is constructed around the HTTP protocol, REST has become a perfect fit. Browsers provide native support for communicating through HTTP, which means that any device with a browser has built-in functionality for accessing REST services.
RESTful web services also support the JSON transport format, which is simply native JavaScript, making it a breeze to consume RESTful services through a browser. While Facebook may have deemed HTML5 unworthy for their mobile needs, a large share of companies have taken the plunge. With HTML5, CSS3, and JavaScript providing a cross-platform solution to mobile device rendering, the option is simply too tempting to ignore.
Technologies like jQuery Mobile and especially Sencha Touch provide a very native feel to browser-based applications. RESTful services using JSON as a transport format are even simple to consume with native apps. Android uses Java so long-standing libraries like Jackson and GSON are available. The JSON framework makes JSON parsing quick and simple with Objective-C. SOAP has so many moving parts that it requires excessive work to support in a browser.
In addition, being chained to XML drives up the cost of ownership for any web service developed with SOAP.
So the next time you are thanking the technical gods that you don't have to look at another WSDL document, just be thankful for the mobile revolution.
