Luis Enrique León's List: Tecnologias Web

• Representational State Transfer (REST) has gained widespread  acceptance across the Web as a simpler alternative to SOAP- and Web Services  Description Language (WSDL)-based Web services. Key evidence of this shift in  interface design is the adoption of REST by mainstream Web 2.0 service  providers—including Yahoo, Google, and Facebook—who have  deprecated or passed on SOAP and WSDL-based interfaces in favor of an  easier-to-use, resource-oriented model to expose their services.
• REST defines a set of architectural principles
• by which you can design Web  services that focus on a system's resources, including how resource states are  addressed and transferred over HTTP
• it's  slated, for example, to become an integral part of Java™ 6 through JSR-311.

• a concrete implementation of a REST Web service  follows four basic design principles:

   
   
  • Use HTTP methods explicitly.
   
  • Be stateless.
   
  • Expose directory structure-like URIs.
   
  • Transfer XML, JavaScript Object Notation (JSON), or both.
• One of the key characteristics of a RESTful Web service is the explicit  use of HTTP methods in a way that follows the protocol as defined by RFC  2616

• This basic REST design principle  establishes a one-to-one mapping between create, read, update, and delete  (CRUD) operations and HTTP methods.  According to this mapping:

     
   
  • To create a resource on the server, use POST.
   
  • To retrieve a resource, use GET.
   
  • To change the state of a resource or to  update it, use PUT.
   
  • To remove or delete a resource, use DELETE.
• there are many cases  of unattractive Web APIs that use HTTP GET to trigger something  transactional on the server—for instance, to add records to a database.  In these cases the GET request URI is not used properly or at least not  used RESTfully.
• the great fit between Ajax and REST has increased the amount of attention REST is getting these days.

7 more annotations...

• A Web service is a software interface that describes a collection of operations that can be accessed over the network through standardized XML messaging.
• Web services can function on a more abstract level that can reevaluate, modify or handle data types dynamically on demand.
• As applications began communicating with each other, the concept of defined universal interfaces for objects became important, allowing objects on other platforms to communicate even if they were written in other programming languages and ran on other operating systems.
• At the most recent step, Web services has moved towards the concept of XML-defined interfaces and communications, finally uniting any kind of application with another, as well as providing the freedom to change and evolve over time, as long as they are designed to the appropriate interface. The versatility of XML is what makes Web services different from previous generation component technologies. It allows the separation of grammatical structure (syntax) and the grammatical meaning (semantics), and how that is processed and understood by each service and the environment it exists in. So now, objects can be defined as services, communicating with other services in XML-defined grammar, whereby each service then translates and analyzes the message according to its local implementation and environment. Thus a networked application can truly be composed of multiple entities of various makes and designs as long as they conform to the rules defined by their service oriented architecture.

• Thus, with this in mind, Web services allow you to:

   
   
  • Interact between services on any platform, written in any language.
   
  • Conceptualize application functions into task, leading to task-oriented development and workflows. This allows a higher abstraction of software that can be employed by less software-technical users that work on business level analytics.
   
  • Allow for loose-coupling, which means that interactions between service applications may not break each time there is a change in how one or more services are designed or implemented.
   
  • Adapt existing applications to changing business conditions and customer needs.
   
  • Provide existing or legacy software applications with service interfaces without changing the original applications, allowing them to fully operate in the service environment.
   
  • Introduce other administrative or operations management functions such as reliability, accountability, security, etc., independent of the original function, thus increasing its versatility and usefulness in the business computing environment.

3 more annotations...