Rest VS GraphQl

                                    When choosing an API design
                                        architecture for a web app for
                                        transferring data, you can make a choice
                                        between REST and GraphQL. REST has
                                        become the industry standard for
                                        designing Web APIs.
                                  
                                    Thus, according to Postman’s 2020 State
                                        of the API Report 93.4% of respondents
                                        were most familiar with REST. By
                                        contrast, GraphQL is a modern
                                        revolutionary alternative for developing
                                        an API. In this article, we will look at
                                        REST and GraphQL, consider their
                                        principles and weigh the pros and cons
                                        of both technologies.
                                  
                                        #Request examples
                                      
                                    Let’s start with the example. We
                                        consider an API for the library. The API
                                        provides information about authors and
                                        their books. Our application fetches the
                                        name of the author, and titles of all
                                        their books by author’s id.
                                  
                                      #REST
                                    
                                    With REST we send two HTTP requests
                                        with empty bodies and receive fixed data
                                        structures:NoneBashCSSCC#GoHTMLJavaJavaScriptJSONPHPPowershellPythonRubySQLTypeScriptYAMLCopy
                                  
                                            1
                                          
                                          Request: GET /author/7
                                        
                                            2
                                          
                                          Response: 200 OK
                                        
                                            3
                                          
                                          {
                                        
                                            4
                                          
                                              "id": 7,
                                        
                                            5
                                          
                                              "firstName":
                                              "Joshua",
                                        
                                            6
                                          
                                              "lastName":
                                              "Bloch",
                                        
                                            7
                                          
                                              "birthday":
                                              "08/28/1961"
                                        
                                            8
                                          
                                          }
                                        
                                            Copied!
                                          
                                    NoneBashCSSCC#GoHTMLJavaJavaScriptJSONPHPPowershellPythonRubySQLTypeScriptYAMLCopy
                                  
                                            1
                                          
                                          Request: GET
                                              /author/7/books
                                        
                                            2
                                          
                                          Response: 200 OK
                                        
                                            3
                                          
                                          [
                                        
                                            4
                                          
                                          {
                                        
                                            5
                                          
                                              "id": 1008,
                                        
                                            6
                                          
                                              "title": "Effective
                                              Java, 3rd Edition",
                                        
                                            7
                                          
                                              "pages": 416,
                                        
                                            8
                                          
                                              "lang":
                                              "en",
                                        
                                            9
                                          
                                              "isbn":
                                              "9780134686097"
                                        
                                            10
                                          
                                              },
                                        
                                            11
                                          
                                              {
                                        
                                            12
                                          
                                              "id": 1010,
                                        
                                            13
                                          
                                              "title": "Java
                                              Puzzlers: Traps, Pitfalls, and
                                              Corner Cases",
                                        
                                            14
                                          
                                              "pages": 312,
                                        
                                            15
                                          
                                              "lang":
                                              "en",
                                        
                                            16
                                          
                                              "isbn":
                                              "032133678X"
                                        
                                            17
                                          
                                              },
                                        
                                            18
                                          
                                              …
                                        
                                            19
                                          
                                          }
                                        
                                            Copied!
                                          
                                    If an author with a specified id does
                                        not
                                        exist:NoneBashCSSCC#GoHTMLJavaJavaScriptJSONPHPPowershellPythonRubySQLTypeScriptYAMLCopy
                                  
                                            1
                                          
                                          Response: 404 Not Found
                                        
                                            Copied!
                                          
                                      #GraphQL
                                    
                                    With GraphQL we send a single request
                                        and define in its body what data needs
                                        to be transmitted. The request is
                                        written in a special query
                                        language:NoneBashCSSCC#GoHTMLJavaJavaScriptJSONPHPPowershellPythonRubySQLTypeScriptYAMLCopy
                                  
                                            1
                                          
                                          Request: POST /graphql
                                        
                                            2
                                          
                                          query {
                                        
                                            3
                                          
                                              author(id: 7) {
                                        
                                            4
                                          
                                              firstName
                                        
                                            5
                                          
                                              lastName
                                        
                                            6
                                          
                                              books {
                                        
                                            7
                                          
                                              title
                                        
                                            8
                                          
                                              }
                                        
                                            9
                                          
                                              }
                                        
                                            10
                                          
                                          }
                                        
                                            11
                                          
                                          Response: 200 OK
                                        
                                            12
                                          
                                          {
                                        
                                            13
                                          
                                              "data": {
                                        
                                            14
                                          
                                              "Author": {
                                        
                                            15
                                          
                                              "firstName":
                                              "Joshua",
                                        
                                            16
                                          
                                              "lastName":
                                              "Bloch"
                                        
                                            17
                                          
                                              },
                                        
                                            18
                                          
                                              "books": [
                                        
                                            19
                                          
                                              {
                                        
                                            20
                                          
                                              "title": "Effective
                                              Java, 3rd Edition"
                                        
                                            21
                                          
                                              },
                                        
                                            22
                                          
                                              {
                                        
                                            23
                                          
                                              "title": "Java
                                              Puzzlers: Traps, Pitfalls, and
                                              Corner Cases"
                                        
                                            24
                                          
                                              }
                                        
                                            25
                                          
                                              ]
                                        
                                            26
                                          
                                              }
                                        
                                            27
                                          
                                          }
                                        
                                            Copied!
                                          
                                    If an author with a specified id does
                                        not
                                        exist:NoneBashCSSCC#GoHTMLJavaJavaScriptJSONPHPPowershellPythonRubySQLTypeScriptYAMLCopy
                                  
                                            1
                                          
                                          Response: 200 OK
                                        
                                            2
                                          
                                          {
                                        
                                            3
                                          
                                              "errors": [
                                        
                                            4
                                          
                                              {
                                        
                                            5
                                          
                                              "message": "Author
                                              with id=7 does not
                                              exist"
                                        
                                            6
                                          
                                              }
                                        
                                            7
                                          
                                              ]
                                        
                                            8
                                          
                                          }
                                        
                                            Copied!
                                          
                                        #REST basics
                                      
                                    REST (Representational State Transfer)
                                        is an architectural concept for web
                                        services that interact over HTTP
                                        protocol. The REST principles were
                                        introduced in 2000 by Roy Fielding in
                                        his Ph.D. dissertation. These principles
                                        are listed below.
                                  
                                      #Client-Server
                                    
                                    An architecture of API should
                                        correspond to the client-server model.
                                        The client and server distribute their
                                        concerns. The server proceeds and stores
                                        data while the client requests resources
                                        and services. Also, the client and
                                        server don’t know the implementation
                                        details of each other. A decoupled
                                        architecture allows to use of the same
                                        server across multiple clients and helps
                                        to reduce software complexity.
                                  
                                      #Stateless
                                    
                                    The server doesn’t store a client
                                        state. So, requests from the client
                                        should contain all needed information to
                                        perform operations and requests are
                                        independent.
                                  
                                      #Cacheable
                                    
                                    Servers, clients, and intermediaries
                                        can cache response data, as cacheability
                                        is one of the standard HTTP protocol
                                        features. Caching decreases interactions
                                        between system components and improves
                                        performance.
                                  
                                      #Uniform Interface
                                    
                                    There are four constraints for the
                                        uniform interface:
                                  
                                            All resources are identified
                                                using URIs (Uniform Resource
                                                Identifiers) and separate from
                                                the representations that are
                                                returned to the client. Any
                                                format, such as JSON or XML, can
                                                be used for data
                                                transmission.
                                          
                                            Representations contain all the
                                                necessary information for
                                                changing resources by the
                                                client.
                                          
                                            Self-descriptive messages
                                                returned to the client should
                                                contain all the information
                                                needed to process them.
                                          
                                            The server should implement
                                                Hypermedia as the Engine of
                                                Application State (HATEOAS),
                                                meaning that the client should
                                                be able to use hyperlinks to
                                                discover available
                                                actions.
                                          
                                      #Layered System
                                    
                                    The client is not aware of the
                                        intermediate components like a proxy,
                                        load balancer, or server that implement
                                        security policies. All intermediate
                                        layers should be invisible to the
                                        client.
                                  
                                      #Code On Demand (optional)
                                    
                                    The server can send an executable code
                                        from the client when requested,
                                        extending client functionality.
                                  
                                        #GraphQL basics
                                      
                                    GraphQL is a query language for APIs
                                        (QL means query language). GraphQL was
                                        started developing in 2012 as an
                                        internal project of Facebook, became
                                        open-source in 2015 and the first stable
                                        version was released in 2018. The key
                                        feature of the language is that the
                                        client decides what data is needed to
                                        obtain from the server.
                                  
                                    Besides, Netflix or Coursera were
                                        working on REST alternatives for
                                        improving API interactions. Netflix has
                                        presented Falcor. However, Coursera
                                        stopped developing its own solution
                                        after Facebook open-sourced
                                        GraphQL.
                                  
                                    Today GraphQL is the winner of this
                                        competition.
                                  
                                    One of the most major GraphQL features
                                        is that it allows clients to query data
                                        from multiple resources in the same
                                        request. All data are fetched from a
                                        single URI.
                                  
                                    GraphQL uses its own type system that
                                        is described by GraphQL Schema
                                        Definition Language (SDL). GraphQL SDL
                                        became part of the specification in
                                        2018. The type system is expressive and
                                        supports polymorphism using interfaces.
                                        A schema defines a graph structure of
                                        data, which means that objects are
                                        connected hierarchically.
                                  
                                        #Pros and Cons
                                      
                                            REST has become the de facto
                                                standard for API development.
                                                It’s a tried-and-proven approach
                                                that has been using for decades
                                                and most developers are familiar
                                                with it.
                                          
                                            With REST the server returns
                                                fixed data structures. But the
                                                client does not always need the
                                                entire dataset that is returned
                                                by the server. GraphQL solves
                                                the problem of over-fetching as
                                                it Enables the client to specify
                                                which data needs to be
                                                fetched.
                                          
                                            When developers are using REST,
                                                they face under-fetching and N+1
                                                requests problem. The client
                                                makes multiple requests to
                                                obtain all data it needs. On the
                                                contrary, GraphQL allows
                                                aggregating the data in a single
                                                query.
                                          
                                            GraphQL uses a strong type
                                                system to define the contract
                                                between the client and the
                                                server using GraphQL SDL. REST
                                                does not require a strict API
                                                definition, but today almost
                                                every RESTful service is defined
                                                using OpenAPI Specification.
                                                OpenAPI, as GraphQL, provides
                                                high expressiveness.
                                          
                                            Since GraphQL uses a single
                                                endpoint, it can not utilize an
                                                HTTP caching mechanism, unlike
                                                REST. There are several ways to
                                                implement caching in GraphQL,
                                                such as Apollo Engine on the
                                                backend and Apollo Client and
                                                Relay on the frontend. However,
                                                HTTP caching wins completely
                                                over these technologies.
                                          
                                            With REST it is easy to
                                                organize error reporting and API
                                                monitoring because REST uses
                                                HTTP response status codes.
                                                Instead, in GraphQL the server
                                                always returns code 200, and
                                                analyzing the response body is
                                                required to capture errors in
                                                interaction.
                                          
                                        #Conclusion
                                      
                                    GraphQL is great for applications where
                                        related and nested data are fetched
                                        because you can use the full power of
                                        its query language.GraphQL is also well
                                        suited for mobile development as
                                        bandwidth usage is optimized by avoiding
                                        over-fetching and under-fetching. But
                                        after weighing the pros and cons, we see
                                        that GraphQL is not always the best
                                        option. If you need a clear and
                                        convenient API without overhead, or you
                                        want to use HTTP capabilities like
                                        caching or authentication, you should
                                        choose REST.
Intro
Next - Server-Side
REST-API
Last modified 14d ago
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Contents
#Code On Demand (optional)
#GraphQL basics
#Pros and Cons
#Conclusion