Why go for GraphQL for integration of your modern APIs?

In a survey conducted involving people working with Application Programming Interfaces (APIs) was conducted, 33.4% of respondents said that GraphQL is one of the most exciting technologies to opt for.

GraphQL is developed by Facebook that was initially applied for mobile applications in 2012. In 2015, GraphQL specifications were outsourced, which is now administered by GraphQL Foundation.

What is GraphQL and why is it important for your modern APIs?

GraphQL is a query language and server-side runtime for APIs and a runtime for fulfilling the queries with your existing data. If you need to have a complete understanding of the data in your API, then GraphQL is your best go! 

With GraphQL, clients will have the ability to procure only what they need and nothing more or nothing less. GraphQL controls the data and not the server, and it always returns predictable results! This makes APIs easily flexible, fast, and developer-friendly.

Terms related to GraphQL:

• Schema: Every possible data that a client can query through a particular service can be described by API developers by creating a schema in GraphQL. A schema consists of object types i.e. the type of object requestable and the fields that it will include.
• Queries: In GraphQL, queries are  to be validated against the schemas, and only then will the validated queries be executed.
• Resolver: Resolver is a function to which the developer attaches each field in a schema, with each generator generating a particular value.

What are the decisions that an API developer takes as far as GraphQl is considered? Well, apart from defining and validating syntax for API queries, from the graphql-spec repository, most of the other decisions are presided by the API designer. GraphQL gives no directions regarding how to store data and developers can use any programming language like JavaScript, PHP, Python, Ruby among others. 

From the viewpoint of a client, the most generic GraphQL operations are probably Queries and Mutations. The priority of these operations can be represented in terms of the Create, Read, Update and Delete (CRUD) model, in which Query is equivalent to Reading and Mutations equivalent to Create, Update and Delete.

What are the advantages of GraphQL?

If you are planning to try GraphQL in a business or enterprise environment, here are some reasons for a positive nod:

1. GraphQL enables an organization to federate its entire API and the GraphQL schema sets a single source of truth in a GraphQL.
2. In a single round trip, GraphQL calls are managed and clients get the requests they want without any over-fetching.
3. Data types are strongly defined so there are no communication hassles between the client and the server.
4. GraphQL is ideal for auto-generating documents because of its introspective feature in which the clients can request a list of data types.
5. Without breaking existing queries, an application API can be evolved in GraphQL.
6. Features that are not available with Rest API can be accessed from the open-source GraphQL extensions.
7.  A particular application architecture need not be dictated, but introduced on top of an already existing Rest API and is workable with existing API management tools.\

What are GraphQL Best Practices?

The GraphQL specifications are purposefully unstated on many critical issues faced by API related to network, authorization, and pagination. It  does not mean that GraphQL has no solutions for these issues, but it simply means that these issues are outside the description of GraphQL. 

The best practices mentioned in the coming section are tactical suggestions for solving recurring issues like serving over HTTP and authorization.

HTTP

While Rest API uses a suite of URLs that expose a single resource, GraphQL is typically served over HTTP through a single endpoint that deliberates a full set of service capabilities. GraphQL is usable alongside a suite of resource URLs but will be a little incompatible with tools like GraphiQL.

JSON GZIP

Despite JSON GZIP not being in the GraphQL specifications, it typically responds to it. JSON is a familiar framework for clients as well as API developers, which is easily readable and debuggable. GraphQL syntax is partially inspired by the JSON syntax.

Versioning

GraphQL avoids versioning by providing resilient tools for the continuous evolution of a GraphQL schema, even though GraphQL can be versioned like any other REST API by all means.

There will be only limited control over the data returned from an API endpoint, any changes can be assumed as a breaking change that requires a new version. The understandability and maintainability of an API becomes difficult with adding new features and constant releases. GraphQL has a different way of dealing with this- it returns those data that are explicit;y requested, without creating a breaking change through adding new types and new fields on those types. Hence this practice is the most opted to avoid breaking changes and serving a version less API.

Nullability

By default, the GraphQL type system has nullable fields. When the network is supported by databases and other services, there are chances that a database crashes or an asynchronous action fails or an exception gets removed. When fields are nullable by default, the fields would return ‘null’ rather than a request failing because of the aforementioned reasons. In the case of GraphQL, when a client raises a request for a non-null field, it will never return null, but will instead set the parent field to ‘null’ when an error occurs.

During the designing phase of GraphQL schema, the designer has to take care of the potential issues if ‘null’ is set as the appropriate value for a failed field.

Pagination

In GraphQL, some fields can  return a list of values. But the -pagination of longer lists of values is left to the decision of the API designer. GraphQL has many API design possibilities for pagination that come with a combination of pros and cons.

APIs feature-efficient paved the way to a best practice pattern termed Connections. Connections tools of clients like Relay can therefore provide automatic support for pagination from the client side when this pattern is integrated by GraphQL.

Server-side batching and caching

Clean codes can be written on the server-side using GraphQL with each field on each type having a focussed on single-purpose function for value resolution. However, there can be repeated data loading from your servers if the GraphQL service is inexperienced or naive. When there are such multiple data requests from the backend in a short period to an underlying database or microservice, the batching technique has opted, and for this tools like DataLoader from Facebook.

Endnote:

Why should companies go for GraphQL? GraphQL is a strong enabler for both API developers and consumers because:

• Through one unified API, organizations with multiple teams and systems can make their data available easily.
• There is no under fetching or over fetching of data and can fetch only the required data across the related entities.
• It has a self-documenting feature that helps to inspect and try out APIs with minimal efforts.
• It is built around a type system that shows the name and type of each field alongside relationships with different entities.
• It can encourage different approaches to API modifications.

Want to build an evolvable and queryable API? Then GraphQL is the right choice. With GraphQL, there will be minimal complexity involved for internal systems for data retrieval. It uses a type system that leads to automatic and updated API documentation at all times. Furthermore, its tooling and ecosystem is what qualifies GraphQL as a potential tool not just for the developers, but for your clients too.