What are REST and RESTful? | Rest vs Restful vs Soap
REST and RESTful are always among the most important and most used structures of the software and informatics world. Although both have separate definitions, these concepts are structures used especially on web services.
What is REST?
First of all, if we need to focus on the concept of REST, it actually means “Representational State Transfer”, although it is an abbreviation, and it forms the Turkish equivalent of “Representational State Transfer”. Although it is a protocol, it uses web protocols and technologies with a distributed system structure.
It is a service structure used for faster and more practical communication between the client-server, that is, between the user and the server. This system, which was first used by Roy Thomas Fielding in 2000 and was introduced in the context of his doctoral thesis, has been used until today and still has an important place.
As it is known, previously, SOAP or WSDL based web services were used instead of this protocol. However, REST, developed as an alternative to these services, works on HTTP. Thanks to its basic and minimum content, which is one of its most basic features, it provides a much more efficient and faster use compared to other web services, thanks to its data exchange feature.
Along with its most basic task, REST carries out data transport operations such as JSON or XML in order to perform application communications between user-server, that is, client-server.
What is RESTful?
Along with creating a REST architectural structure, this architectural structure has its own principle and when it is used with the specified features, RESTful service emerges as a result of this use. In other words, in terms of a clear definition, it can be said that they are web services that use REST architecture for RESTful.
RESTful services, which generally work over the HTTP protocol, provide communication through HTTP methods such as DELETE, PUT, POST in order to transfer pages used in browsers such as Safari, Google Chrome, Mozilla, Opera on internet browsers used on computers or devices.
REST Architecture and History
This service, which was developed in 2000, was actually developed by Roy Thomas Fielding by starting a study between 1996-1999. Because Fielding has started to develop this style since 1996 in a similar way with the HTTP 1.1 design that was revealed, considering the design on HTTP 1.0. In this context, the emerging architecture has features that are considered advantageous or disadvantageous.
Looking at the features of the REST architecture, among some impressive features, for example, performance ranks first. Because this architecture has a dominant advantage in terms of performance, especially as determined by users. Considering the other features of the architecture,
- It has a very simple and convenient interface.
- REST provides communication visibility between components by service agents, that is, by service proxies.
- Changes can be made to the components in order to properly fulfill different needs.
- When the program code is moved along with a data, the desired component can be moved easily.
- Scalability can also be achieved through interaction between components in many different numbers of components.
- Fault-resistance security is always achieved on all data, connections or components at the system level.
Limitations in REST Architecture
In fact, these points, which can be seen as both limitations and some constraints, express the working principles between which points within the REST architecture. Therefore, anyone who wants to work with REST and RESTful should also be aware of these restrictions.
Considering the stateless first, for example, a client-related session or context cannot be maintained on the server. Because in every request made by the user, the server carries the requested information to create a response and this information is always kept by the user, but only when needed, the server is notified with the request.
In fact, this is an important point in terms of scalability, and it eliminates the storage of any data between requests on the server and provides a much more practical resource management. In addition, in terms of visibility, the information contained in the request is sufficient for the server to understand the purpose of the request.
However, this limitation, which has an important point, also reveals some disadvantages. Because the client has to add some information in every request it makes, and therefore the network traffic starts to get concentrated. While this situation causes problems for the server to control application consistency, the server encounters a much larger validation load in the face of different requests from different users.
Although there is a simple and practical interface, this is an important principle for REST. In this way, communication becomes much simpler, and thanks to the common interface, each part can undergo different evolutions independently. Underneath this is a detail about HTTP methods, which will be discussed more clearly later.
Code On Demand
Along with the code-on-demand limitation, the server may choose to send executable scripts in some cases to create a more functional situation on the user’s side. As a result of this activity, sometimes it creates an optional restriction since the visibility is low. From a different perspective, a server cannot be called a fully RESTful service if it does not have other limitations other than the code on demand limitation.
Client-Server Architecture (User-Server Architecture)
Although the client-server architecture is actually the most important limitation of this architecture, it reveals the logic that the user does not have any knowledge of the data source on the server-side and that the server creates the correct answers in the face of the correct requests. In other words, there is an independent relationship between the client and the server. The main purpose here is to achieve an independent platform operation and to increase the scalability rate. Moreover, when the interface between these two units continues to be used in a common way, they can continue to develop independently of each other.
Ability to be Cached
The response, that is, the effect coming over HTTP can be cached by the client. For this reason, the server should always express whether it is cachable or not with the responses it sends. Because this is very important in terms of performance.
The fact that the server architecture has a layered structure is due to the fact that it is not known whether the connection is made to the last server or to an intermediate server when the connection is made by the client. Thanks to this structure, it provides more scalability as it provides balance changes with intermediary servers, while users can enforce certain security steps. In addition, in this case, it can be used at points where encapsulation is needed. However, when this pipeline is used too much, there may be delays in the client-server connection.
HTTP Methods Used on REST
HTTP methods that RESTful services should use together with REST architecture can be reviewed separately and used depending on preferences during application development stages. For this reason, it may be necessary to review the methods one by one and look at their properties. Among the methods to be mentioned, there will be methods such as GET, POST, DELETE and PUT.
GET method; Although this method is generally used when viewing and data listing operations are desired, the request operations must have a secure structure. When sending data using this method, while sending is provided in the address bar, if it does not appear in the address bar, it will cause the process to be unreliable. Therefore, it would be more accurate to send data using MD5 encryption to perform a reliable transmission.
POST method; This method, on the other hand, is used for updating the data and adding new data, but it provides a safer use instead of displaying in the address bar compared to the GET method.
DELETE method; In this method, it is used to perform data deletion operations.
PUT method; Although it is mainly preferred for data update operations and the POST method is also used for data update, PUT provides the same result even if it is repeated as many times as desired for the purpose of the request.