In recent years, GraphQL has gained significant traction as a powerful alternative to traditional RESTful APIs. Developed by Facebook, GraphQL offers a more flexible and efficient way to query and manipulate data. In this blog post, we will delve into the fundamentals of GraphQL, its advantages, and how to implement GraphQL APIs.
Let's first understand what is GraphQL
GraphQL is a query language and server-side runtime for application programming interfaces (APIs) that prioritizes giving clients exactly the data they request and no more.
GraphQL is designed to make APIs fast, flexible, and developer-friendly. It can even be deployed within an integrated development environment (IDE) known as GraphiQL. As an alternative to REST, GraphQL lets developers construct requests that pull data from multiple data sources in a single API call.
Additionally, GraphQL gives API maintainers the flexibility to add or deprecate fields without impacting existing queries. Developers can build APIs with whatever methods they prefer, and the GraphQL specification will ensure they function in predictable ways to clients.
GraphQL common terms
SCHEMA - API developers use GraphQL to create a schema to describe all the possible data that clients can query through that service. A GraphQL schema is made up of object types, which define which kind of object you can request and what fields it has.
QUERIES - As queries come in, GraphQL validates the queries against the schema. GraphQL then executes the validated queries.
RESOLVER - The API developer attaches each field in a schema to a function called a resolver. During execution, the resolver is called to produce the value.
When should you use GraphQL?
GraphQL is an excellent solution to a unique problem around the building and consuming APIs. When used as designed, it can be an ideal tool for the use cases described below:
Data fetching control
- GraphQL was designed to allow the client to ask for only the data it needs. While the server might be able to deliver more data to the client for a single request, it would only send the data requested by the client. If you want the client to control the type and amount of data it needs, GraphQL would be ideal for your project.
Using multiple data sources
- GraphQL simplifies the task of aggregating data from multiple sources or APIs and then resolving the data to the client in a single API call. On the other hand, API technologies like REST would require multiple HTTP calls to access data from multiple sources.
Alleviating bandwidth concerns
- Bandwidth is a problem for small devices like mobile phones, smartwatches, and IoT devices that are not able to handle large amounts of data. Using GraphQL helps minimize this issue. Because GraphQL allows the client to specify what data it needs, the server doesn’t send excess data, which could reduce the app’s performance when bandwidth is limited.
- GraphQL exposes a single endpoint that allows you to access multiple resources. In addition, resources are not exposed according to the views that you have inside your app. So, if your UI changes, for example, requiring either more or less data, it doesn’t have an impact or require changes on the server.
Let's take a look at the difference between requests made in REST API vs GraphQL
Advantages and Disadvantages of GraphQL
A GraphQL schema sets a single source of truth in a GraphQL application. It offers an organization a way to federate its entire API.
GraphQL calls are handled in a single round trip. Clients get what they request with no over-etching.
Strongly defined data types reduce miscommunication between the client and the server.
GraphQL is introspective. A client can request a list of data types available. This is ideal for auto-generating documentation.
GraphQL presents a learning curve for developers familiar with REST APIs.
GraphQL shifts much of the work of a data query to the server side, which adds complexity for server developers.
Depending on how it is implemented, GraphQL might require different API management strategies than REST APIs, particularly when considering rate limits and pricing.
Caching is more complex than REST.
GraphQL and Open Source
GraphQL was developed by Facebook, which first began using it for mobile applications in 2012. The GraphQL specification was open-sourced in 2015. It is now overseen by the GraphQL Foundation.
There are a variety of open-source projects that involve GraphQL. The list below is not exhaustive but includes projects designed to facilitate the adoption of GraphQL.
Offix is an offline client that allows GraphQL mutations and queries to execute even when an application is unreachable.
Graphback, a command line client for generating GraphQL-enabled Node.js servers.
OpenAPI-to-GraphQL, a command-line interface and library for translating APIs described by OpenAPI Specifications or Swagger into GraphQL.
GraphQL is a powerful tool, and there are many reasons you might choose GraphQL over REST. But, if your tolerance for slow performance and complexity is low, you might want to steer clear and consider using a REST architecture instead.
That's it for now!! Hope you got to learn something about GraphQL, how it's different from REST, and what are some pros and cons of using it.