What is SOAP and REST
Both are 2 different approaches to transmitting data over a network. They define how to build Application Programming Interface(API).
What is an API?
It is a set of rules that controls the interaction between software. It does not allow us to dive into their source code of some third party software while we could access to their privileges.
SOAP (Simple Object Access Protocol)
It is a highly extensible protocol that can be sent over any protocol. Eg. HTTP(Web browser), SMTP(Email), TCP, or JMS. SOAP message should be transferred in XML (human and machine readable) format. It gives some built-in compliance standards (eg. security, atomicity, consistency, isolation, and durability), which is a set of properties for ensuring reliable database transactions.
It has some Web Service specifications mentioned below:
- Web Services security (WS-security): Standardizes how messages are secured and transferred through unique identifiers called tokens.
- WS — Reliable Messaging: Standardizes error handling between messages transferred across unreliable IT infrastructure.
- Web Services addressing (WS — addressing): Packages routing information as metadata within SOAP headers, instead of maintaining such information deeper within the network.
- Web Services Description Language (WSDL): Describes what a web service does, and where that service begins and ends.
REST(Representational State Transfer)
It is an architectural principles. Usually request is sent over stateless communications protocol(Http). And the response will be in any format : HTML, XML, plain text, and JSON. JSON is mostly preferred format (Read by any programming language, Human and machine readable, lightweight). RESTful APIs are more flexible and easier to set up. It is very data-driven, function-driven compared to SOAP. REST relies on a simple URL to make a request. But in some situations you must provide additional information. Basic REST HTTP requests : POST, GET, PUT, and DELETE
To make REST asynchronous we use message broker.
A RESTful application must follow below mentioned architectural guidelines:
- A client-server architecture :- Client sends requests and waits for the response; Server then takes the opposite role. The main reason for this constraint is one side doesn’t care about anything except the correct format of the interaction.
- Stateless client-server communication :- Server doesn’t save any information from the client and requires it in each request.
- Cacheable :- Client could save some data on the local storage (cache).
- A uniform interface between components :- Information is transferred in a standardized form instead of specific to an application’s needs.
- A layered system constraint :- Client-Server interactions can be mediated by hierarchical layers. It is useful because layers don’t know anything about each other and server could easily be scaled with new layers (e.g., security).
- Code on demand :- Allowing servers to extend the functionality of a client by transferring executable code (This an optional guideline).
SOAP provides the following advantages when compared to REST:
• Language, platform, and transport independent (REST requires use of HTTP)
• Works well in distributed enterprise environments (REST assumes direct point-to-point communication)
• Provides significant pre-build extensibility in the form of the WS* standards
• Built-in error handling
• Automation when used with certain language products
REST is easier to use for the most part and is more flexible. It has the following advantages over SOAP:
• No expensive tools require to interact with the web service
• Smaller learning curve
• Efficient (SOAP uses XML for all messages, REST can use smaller message formats)
• Fast (no extensive processing required)
• Closer to other web technologies in design philosophy
Differences between SOAP and REST
SOAP has SSL( Secure Socket Layer) and WS-security whereas REST has SSL and HTTPS. SOAP is preferred in the case of Bank Account Password, Card Number, etc.
REST APIs are lightweight, ideal for newer contexts Eg. Internet of Things, mobile application development, and serverless computing. SOAP web services offer built-in security and transaction compliance that align with many enterprise needs, but that also makes them heavier. Many public APIs Eg. Google Maps API, follow the REST guidelines. Typically, an API will adhere to either REST or SOAP, depends on application requirements, environment, and the programming language and preferences of the developer.
I hope you got an idea of SOAP and REST.