README.md

# Absinthe.Relay

[![Hex pm](http://img.shields.io/hexpm/v/absinthe_relay.svg?style=flat)](https://hex.pm/packages/absinthe_relay)[![License](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)

Support for the [Relay framework](https://facebook.github.io/relay/)
from Elixir, using the [Absinthe](https://github.com/absinthe-graphql/absinthe)
package.

## Installation

Install from [Hex.pm](https://hex.pm/packages/absinthe_relay):

```elixir
def deps do
  [{:absinthe_relay, "~> 1.4.0-rc or ~> 1.4"}]
end
```

Note: Absinthe requires Elixir 1.4 or higher.

## Upgrading

See [CHANGELOG](./CHANGELOG.md) for upgrade steps between versions.

You may want to look for the specific upgrade guide in the [Absinthe documentation](https://hexdocs.pm/absinthe).

## Documentation

See "Usage," below, for basic usage information and links to specific resources.

- For the tutorial, guides, and general information about Absinthe-related
  projects, see [http://absinthe-graphql.org](http://absinthe-graphql.org).
- Links to the API documentation are available in the [project list](http://absinthe-graphql.org/projects).

### Roadmap

See the Roadmap on [absinthe-graphql.org](http://absinthe-graphql.org/roadmap).

## Related Projects

See the Project List on [absinthe-graphql.org](http://absinthe-graphql.org/projects).

## Usage

Schemas should `use Absinthe.Relay.Schema`, optionally providing what flavor of Relay they'd like to support (`:classic` or `:modern`):

```elixir
defmodule Schema do
  use Absinthe.Schema
  use Absinthe.Relay.Schema, :modern

  # ...

end
```

For a type module, use `Absinthe.Relay.Schema.Notation`

```elixir
defmodule Schema do
  use Absinthe.Schema.Notation
  use Absinthe.Relay.Schema.Notation, :modern

  # ...

end
```

Note that if you do not provide a flavor option, it will choose the default of `:classic`, but warn you
that this behavior will change to `:modern` in absinthe_relay v1.5.


See the documentation for [Absinthe.Relay.Node](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Node.html),
[Absinthe.Relay.Connection](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Connection.html), and [Absinthe.Relay.Mutation](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Mutation.html)  for
specific usage information.

### Node Interface

Relay
[requires an interface](https://facebook.github.io/relay/docs/en/graphql-server-specification.html#object-identification),
`"Node"`, be defined in your schema to provide a simple way to fetch
objects using a global ID scheme.

See the [Absinthe.Relay.Node](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Node.html)
module documentation for specific instructions on how do design a schema that makes use of nodes.

### Connection

Relay uses
[Connection](https://facebook.github.io/relay/docs/en/graphql-in-relay.html#connectionkey-string-filters-string)
(and other related) types to provide a standardized way of slicing and
paginating a one-to-many relationship.

Support in this package is designed to match the [Relay Cursor Connection Specification](https://facebook.github.io/relay/docs/en/graphql-server-specification.html#connections).

See the [Absinthe.Relay.Connection](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Connection.html)
module documentation for specific instructions on how do design a schema that makes use of nodes.

### Mutation

Relay supports mutation via [a contract](https://facebook.github.io/relay/docs/en/graphql-server-specification.html#mutations) involving single input object arguments (optionally for Relay Modern) with client mutation IDs (only for Relay Classic).

See the [Absinthe.Relay.Mutation](https://hexdocs.pm/absinthe_relay/Absinthe.Relay.Mutation.html) module documentation for specific instructions on how to design a schema that makes use of mutations.

## Supporting the Babel Relay Plugin

To generate a `schema.json` file for use with the [Babel Relay Plugin](https://facebook.github.io/relay/docs/en/installation-and-setup.html#set-up-babel-plugin-relay), run the `absinthe.schema.json` Mix task, built-in to [Absinthe](https://github.com/absinthe-graphql/absinthe).

In your project, check out the documentation with:

```
mix help absinthe.schema.json
```

## More Documentation

See additional documentation, including guides, in the [Absinthe hexdocs](https://hexdocs.pm/absinthe).

## Contributing

Please remember that all interactions in our official spaces follow our [Code of
Conduct](./CODE_OF_CONDUCT.md).

## License

See [LICENSE.md](./LICENSE.md)