Craft Graphql Apis In Elixir With Absinthe Pdf
If you are a developer who wants to create GraphQL APIs in Elixir with Absinthe, then you have come to the right place. In this article, we will discuss the steps you need to take to create GraphQL APIs in Elixir using Absinthe. We will also provide you with a PDF document that you can use as a reference when creating your APIs.
What is GraphQL?
GraphQL is a query language that was developed by Facebook. It provides a way to define the data that a client can request from a server. With GraphQL, clients can specify exactly what data they need, and the server will only send that data back to the client. This can help reduce the amount of data that is sent over the network, which can improve performance.
What is Elixir?
Elixir is a functional programming language that was designed for building scalable and fault-tolerant applications. It runs on the Erlang Virtual Machine (VM), which is known for its ability to handle large-scale concurrent applications.
What is Absinthe?
Absinthe is a GraphQL toolkit for Elixir. It provides a way to define GraphQL schemas and resolvers, and it also provides tools for parsing GraphQL queries and executing them against the schema.
Getting Started
The first step in creating GraphQL APIs in Elixir with Absinthe is to install Elixir and Absinthe. You can install Elixir by following the instructions on the Elixir website. To install Absinthe, you can add it to your project's dependencies in the mix.exs file:
defp deps do
[
{:absinthe, "~> 1.4.0"},
{:absinthe_plug, "~> 1.5.0"}
]
end
After adding Absinthe to your project's dependencies, you can run mix deps.get to fetch the dependencies.
Defining a Schema
The next step is to define a GraphQL schema. A schema defines the types and fields that are available in your API. Here is an example schema:
defmodule MySchema do
use Absinthe.Schema
query do
field :hello, :string do
resolve fn _args, _ctx ->
"world"
end
end
end
end
This schema defines a single query field called "hello" that returns the string "world".
Starting a Server
The next step is to start a server that will handle GraphQL queries. You can use the Plug library to start a server:
defmodule MyServer do
use Plug.Builder
plug Plug.Logger
plug Plug.Parsers, parsers: [:urlencoded, :multipart, :json],
pass: ["*/*"],
json_decoder: Poison
plug Absinthe.Plug, schema: MySchema
plug :match
plug :dispatch
end
This server uses the Absinthe.Plug library to handle GraphQL queries. It also uses the Plug.Logger and Plug.Parsers libraries to log requests and parse JSON requests.
Executing Queries
With your server running, you can now execute GraphQL queries against it. You can use a tool like GraphiQL to execute queries:
In GraphiQL, you can enter a query and execute it against your server. Here is an example query:
{
hello
}
This query will return the string "world".
Conclusion
Creating GraphQL APIs in Elixir with Absinthe is a powerful way to build scalable and fault-tolerant applications. With Absinthe, you can define GraphQL schemas and resolvers, and you can execute GraphQL queries against your API. By following the steps outlined in this article, you can get started with creating GraphQL APIs in Elixir with Absinthe.