# Absinthe.Relay
[](https://travis-ci.org/absinthe-graphql/absinthe_relay)
[](https://hex.pm/packages/absinthe_relay)
[](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)
