Getting started with React and GraphQL: A beginner's guide.

What is GraphQL?

GraphQL is a query language for APIs (Application Programming Interfaces) that was developed by Facebook in 2012 and later open-sourced in 2015. It allows clients to request exactly the data they need and nothing more, enabling more efficient and flexible communication between the client and server. Unlike traditional RESTful APIs, which require multiple endpoints and may return more data than needed, GraphQL provides a single endpoint and lets clients specify their own queries and mutations, resulting in faster and more predictable responses. GraphQL also offers a strong type system and introspection capabilities, making it easier to understand and maintain APIs.

Why GraphQL?

Have you ever found yourself struggling to get the exact data you need from an API? Have you ever wished that you could just ask for the specific information you want and get it in one request, without having to deal with extra data or multiple endpoints? If so, you're not alone. The traditional RESTful API architecture has its limitations, and developers have been looking for a better way to handle data fetching and management.

What we would be learning.

This article is a series and this is the first part. So, if you're new to GraphQL and want to learn how to use it effectively, this beginner's guide is for you.
At the end of this series, we'll cover:

The basics of GraphQL
Its advantages over REST
Comparing GraphQL and Rest API responses.
The core concepts of GraphqL a frontend developer must know.
How to setup, use and fetch data from GraphQL API using Apollo client in the frontend.

Also, by the end of this series, you'll have a solid understanding of how GraphQL works and we are going to build a small react project that fetches data from a GraphQL API and also use some of the concepts we are oing to discuss in the series. Let's get started!

Some concepts of GraphQL a developer should know.

As a developer, there are a few concepts of GraphQl you should know. Some of them are listed below.

Schema: A GraphQL schema is a blueprint that defines the types of data available in the API and the operations that can be performed on that data. It defines the queries, mutations, and subscriptions that can be made to the API, as well as the types of data that can be returned.
Query: A query is a request for data from the API. In GraphQL, queries are written using the GraphQL query language, and can be used to retrieve data in a flexible and efficient way. Queries can specify the exact data that is needed, and can include nested fields to retrieve related data.
Mutation: A mutation is a request to modify data in the API. In GraphQL, mutations are written using the GraphQL mutation language, and can be used to create, update, or delete data in the API. Mutations can include input arguments to specify the data to be modified.
Resolver: A resolver is a function that is responsible for resolving a query or mutation. Resolvers determine how the data should be retrieved or modified, and return the requested data or confirmation of the mutation. Resolvers are associated with specific types in the schema, and can be written in any programming language.
Type: A type is a defined object or scalar in the GraphQL schema. Types can include objects, interfaces, unions, scalars, and enums. Each type has one or more fields, which define the data that can be retrieved or modified for that type.
Subscription: A subscription is a request for real-time data updates from the API. In GraphQL, subscriptions are written using the GraphQL subscription language, and can be used to subscribe to specific data changes and receive updates as they occur.

However, it is of best practice for frontend engineers to know how to interact with GraphQL APIs.

Advantages of GraphQL over Rest

GraphQL has several advantages over rest, some of them are listed below.

Efficient data fetching: With REST, each endpoint returns a fixed set of data, which can lead to over-fetching or under-fetching of data. In contrast, GraphQL enables clients to request only the specific data they need, resulting in faster and more efficient data fetching.
Reduced network traffic: RESTful APIs may require multiple requests to fetch all the necessary data, while GraphQL allows for the retrieval of all required data in a single request, reducing the overall network traffic.
Improved developer experience: GraphQL provides a strongly typed schema that allows for easier development and understanding of the API. It also supports introspection, which enables automatic documentation generation, type checking, and API exploration.
Flexibility: GraphQL's flexible and dynamic nature allows clients to define their own queries and mutations, enabling a more customizable and adaptable API.
Real-time data: GraphQL subscriptions allow for real-time data updates, providing a more interactive and responsive user experience.

Disadvantages of GraphQL compared to Rest.

While GraphQL has many advantages over traditional RESTful APIs, there are a few potential disadvantages to consider:

Complexity: GraphQL can be more complex to set up and use compared to RESTful APIs, particularly for developers who are not familiar with the technology. It requires a different approach to data modeling and can be more difficult to implement.
Caching: With RESTful APIs, clients can take advantage of HTTP caching, which can help to reduce server load and improve performance. With GraphQL, caching can be more challenging due to the dynamic nature of the queries, and caching can become less effective when the data is frequently updated.
Server Load: GraphQL queries can be more complex and more computationally intensive than RESTful API requests, which can lead to higher server loads and slower response times, particularly if queries are poorly optimized or clients request large amounts of data.
Tooling: While there are many libraries and tools available for working with GraphQL, the ecosystem is not as mature as that of RESTful APIs. This can make it more difficult to find resources and solutions when issues arise.

Despite these potential disadvantages, many developers have found that the benefits of GraphQL far outweigh any drawbacks. As with any technology, it's important to carefully evaluate the pros and cons and determine whether GraphQL is the right choice for your particular use case.

Overall, GraphQL provides a more efficient, flexible, and developer-friendly way to interact with APIs compared to traditional RESTful APIs.

Comparing The Data Retrieval from a GraphQL API and Rest API.

As we have explained earlier, the responses gotten from a GraphQL API and a Rest API are quite different because the GraphQL API gives us the specific data, and this is because when fetching data from a GraphQL API, we have to specify the fields that we want and by doing this it is going to return the data for only the fields queried for. On the other hand, a Rest API gives us both the data we need and the ones we don't. We can check the images below for a clear understanding.

The image above is an example of a GraphQL query and it's response.

The image above is an example of a response from a Rest API.

Conclusion

So far in this first part of the series, we have been able to cover the following.

Introduction to GraphQL
Why we should use GraphQL
Advantages of GraphQL API over Rest API.
Disadvantages of GraphQL API compared to Rest API.
We listed out some of the core concepts of GraphQL.
We compared the responses of both GraphQL and Rest APIs

In summary, GraphQL is an exciting and promising technology that is worth exploring, especially for developers looking to build modern, efficient, and scalable applications.