SOAP and REST are the two widely-adopted options for accessing web services. A web service is a collection of protocols and standards that are used to exchange data between systems or applications. It enables applications to interact with each other over the internet, regardless of the language they are written in or the platform they are running on.
In this article, you will learn the differences between SOAP and REST. We will also highlight the scenarios in which they fit the best.
Simple Object Access Protocol (SOAP)
SOAP is a standards-based protocol for accessing web services. While SOAP messages can only be formatted in XML, they can be transported using a variety of transport protocols such as HTTP, FTP, SMTP, XMPP, or any other protocol that can transfer text.
A typical SOAP message structure:
Envelope: It is the root element in every SOAP message. It contains two child elements: Header and Body.
Header (Optional): It is used to pass application-related information that is to be processed along the message path.
Body: It contains the message intended for the ultimate recipient.
Fault (Optional): It is used for reporting errors.
How SOAP works
SOAP works by exchanging the XML envelopes:
The consumer creates a request envelope (an XML document) and sends it to the server over a transport protocol, typically HTTPS.
The provider parses the XML request to read the method name and parameters passed and delegated for processing.
The XML response is then sent back to the consumer, containing the return value or fault data of the method call.
Finally, the consumer parses the response XML to make use of the return value.
Use cases
SOAP is a great option for scenarios that involve non-HTTP transports, asynchronous processing, strict agreements, stringent security requirements, and stateful operations. Its rigid structure, security, and authorization capabilities make it the most suitable option for:
Representational State Transfer (REST)
REST is an architectural style, which can be characterized by these six architectural constraints: uniform interface, client-server architecture, stateless, cacheable, layered system, and code-on-demand. It was originally described in 2000 by Roy Fielding in his doctoral dissertation.
REST permits not only XML but also other file types like JSON. It relies on a stateless, client-server protocol, almost always HTTP. These are the commonly-used HTTP methods for all CRUD operations:
POST: Submit data enclosed in the body to a specified resource.
GET: Retrieve data from a specified resource.
PUT: Update a specified resource.
DELETE: Delete a specified resource.
How REST works
REST treats everything as a resource. As opposed to SOAP, where we send an entire envelope, REST is more like sending a postcard. The consumer needs to mention two things in a REST request:
Resource URI or an endpoint: An identifier for the resource you are interested in.
Operation: The operation you want the server to perform on that resource, in the form of an HTTP method, or verb.
The provider will then respond with a representation of the state of the requested resource. This representation of the state can be in a JSON, XML, or HTML format.
Use cases
REST is great for scenarios that involve limited bandwidth and resources, stateless operations, and require caching. Many developers do suggest that “any time you do not need the additional features of SOAP, use REST.”
Its simplicity, flexibility, discoverability, and scalability make it a suitable option for:
SOAP VS REST: Key differences
As we saw, both SOAP and REST have their pros and cons. SOAP has strict standards, but its rich security features make it a perfect choice for billing operations and payments. REST is simple and approachable but does lack standards. Knowing their tradeoffs, you can now make an informed decision to pick the one that fits your project best.
Comments
Post a Comment