Apollo Kotlin, a popular GraphQL client, is commonly used by developers worldwide to generate Java and Kotlin models. This platform acts as a library that enables users to utilise the GraphQL backend through reverting query-specific results by carrying out queries against GraphQL servers.

Formerly referred to as Apollo Android, Kotlin is used to generate these models from different GraphQL queries.

To execute an Apollo Android KT, in this article, we’ll be shedding some light on some unique features of Apollo Kotlin and what makes GraphQL an ideal choice over Rest API. We will also share detailed insights on how to implement GraphQL in an Android Studio. You will require an Apollo GraphQL plugin, runtime dependency, and generated models.

Apollo Koltin: Introduction & Unique Features

Apollo Koltin is a multi-platform library that’s developed considering Android. When you configure Apollo, the generated models will make models for your queries. This means whatever query you write, you will receive a model class for the same automatically. Normally you would have to make a data class from scratch, but this won’t be your concern here. Simply place your schema in the application, and you are good to go.

Here are a few unique features the GraphQL client’s well-known for:

• Normalized cache along with HTTP cache.
• Availability of fake models for testing purposes.
• Multi-platform code generation (both JavaScript and Koltin).
• Auto persisted queries with batching facilities.
• Reflection-free parsing

GraphQL Vs. Rest API: Why does GraphQL Have An Edge?

GraphQL has become a top preference for developers seeking to build APIs. The platform offers a plethora of tools to streamline API consumption, including Apollo Koltin: A library that enables developers to utilize GraphQL queries to execute operations. GraphQL offers feasibility by directing you to download the schema through a simple command. You will need to give an endpoint parameter and where you want to save the schema accordingly.

While GraphQL is a query language, REST is more of an architectural concept utilised by network-oriented software. Rest API has default code, but GraphQL backend isn’t like that. It’s distinct and enables programmers to view and access all the queries in the backend. Additionally, you can view and access your schema as well. For the REST API, you will need to browse through some documentation.

A shortcoming is that these documentations change from time to time, making things a bit hectic and time-consuming. Here are a few other differences between the two:

1. GraphQL utilizes a single endpoint, and it’s run over HTTP. The sole endpoint is sufficient to enable you to utilize the service to its complete potential. On the other hand, REST makes use of URLs to operate. Every URL will direct you to an individual source.
2. GraphQL makes use of an architecture that is more client-focused. However, REST API utilizes an architecture that’s only server-driven.
3. While GraphQL doesn’t incorporate an in-built caching model, REST API automatically facilitates caching.
4. You won’t need any API versioning while using GraphQL but REST supports and utilizes a plethora of API versions.
5. GraphQL provides auto-generated documentation, unlike the REST API. It also offers programmers type safety, another feature that REST lacks.

Implementing GraphQL in Android Studio

To summarize the entire process: You will need to include libraries and download a scheme. Once done, set the package and make sure you use generator models.

To add Apollo to your project, add following lines to your build.gradle.kts file:

plugins {
  id("com.apollographql.apollo3").version("3.X.X")
}

And then, add the runtime dependency:

dependencies {
implementation("com.apollographql.apollo3:apollo-runtime:3.7.1")
}

And set the package name for generated models:

apollo {
  packageName.set("com.example")
}

The next step would be to go to your deployment link to connect with other clients. You can connect with any client on Apollo.

Once you’ve visited the deployment link, use the query to see what response will come and whether any parameters are required or not. Similarly, write the queries and run them to see if a response is coming or not. Lastly, copy-paste it in Android Studio and keep a sensible name for clarity.

Download a schema

The first step to implementing GraphQL in an Android Studio would be downloading a schema. You can do so by running a command that can be easily found on any tutorials and leaving it once done. Apollo Koltin can understand at what time the backend will return.

Writing Queries

Before writing a query, the ‘getCategories’ query will have an ID and name. In case you want to run a simple query, in the response, you will require an ID and name along with your backend. Giving a name is relatively simple because whatever name you give above, it will become the name of your Android studio reference.

While writing queries, keep in mind that the query will be visible in the ‘project’ section and not the ‘Android’ section. Often, programmers browse through the ‘Android’ section to view their queries and cannot find them. Also, queries can’t be empty, so you will have to pass a query.

The Essence of an Apollo Client

Apollo Koltin needs an Apollo client to redirect a response. In this process, it will utilise an HTTP client that the Apollo client will also use. The process is quite simple: give a client, communicate to them your query, and pass parameters accordingly.

Generator models

Apollo doesn’t require you to input and write the Class from your side. You can simply write the query, and the generator models will generate the query. Koltin will know the type of your query through the schema and the data class.

Passing parameters

Passing parameters in Apollo Koltin is easy. You write a normal query and pass it with a parameter. The normal function will run; it’ll catch a normal query with the parameter and work like magic.

Bottom Line

We have discussed everything you need to know in detail about Apollo Koltin and how GraphQL can be implemented on the platform. Programmers primarily prefer Apollo Koltin due to the features listed above and its convenience in terms of queries and classes. Additionally, GraphQL is a better alternative to REST APIs for many reasons, a few of which we’ve listed above for your reference.