Maple
WARNING: This release is just for posterity. There is a major rewrite coming.
Maple is an automatic, compile time, client code generator for GraphQL schemas. At best it creates easy to use API functions for use in your code. At worst it can be used as a CLI for a GraphQL API.
Best illustrated by an example - given the following code
defmodule Maple.Examples.Github.Config do
Application.put_env(:maple, :api_url, "https://api.github.com/graphql")
Application.put_env(:maple, :additional_headers, %{"Authorization" => "Bearer TOKEN"})
end
defmodule Maple.Examples.Github do
use Maple
end` will create all the query and mutation functions for the GitHub GraphQL API.
So you can do the following:
```elixir
iex(1)> c "examples/github.ex", "." # We need to compile the BEAM file to access the documentation
[Maple.Examples.Github, Maple.Examples.Github.Config]
iex(2)> h Maple.Examples.Github.user
def user(params, fields)
Lookup a user by login.
Param name: login
• Description: The user's login.
• Type: String
• Required: Yes
iex(3)> Maple.Examples.Github.viewer("login")
%Maple.Response{body: %{"viewer" => %{"login" => "maxneuvians"}}, status: 200}
iex(4)> Maple.Examples.Github.user(%{login: "maxneuvians"}, "name")
%Maple.Response{body: %{"user" => %{"name" => "Max Neuvians"}}, status: 200}
iex(5)> Maple.Examples.Github.user(%{},"name")
{:error, "Query is missing the following required params: login"}
```queryfunctions can are either arity/1or/2depending if they have required params.mutationfunctions
are always arity/2. Arity/2functions always take amapas the first argument and astringas the second,
which match the GraphQLparamsandfieldsconcept.
Function names are changed from camel to snake case. exlistUsersbecomeslistusers.
Take a look atexamples/for more examples.
## Subscriptions
It appears that at this point in time the support of subscriptions over web sockets are a work in progress.
For example, [https://github.com/apollographql/subscriptions-transport-ws/](https://github.com/apollographql/subscriptions-transport-ws/)
implements a legacy (graphql-subscriptions) and a current (graphql-ws) web socket subprotocol for Apollo servers. For more information please take a look here: [https://github.com/apollographql/subscriptions-transport-ws/blob/master/PROTOCOL.md](https://github.com/apollographql/subscriptions-transport-ws/blob/master/PROTOCOL.md)
Once Absinthe 1.4 has been released I will implement it as an adapter. Here is an example interaction with a Scaphold.io API:
```elixir
iex(1)> Maple.Examples.Scaphold.subscribe_to_post(%{mutations: ["createPost"]}, "mutation value {id content title}", &Maple.Examples.Scaphold.result/1)
18:40:22.932 [info] Connected!
:ok
18:40:23.432 [info] Successful subscription
iex(2)> Maple.Examples.Scaphold.create_post(%{input: %{title: "Hello", content: "World"}},"id")
18:45:24.977 [info] Received subscription data
%{"data" => %{"subscribeToPost" => %{"mutation" => "createPost",
"value" => %{"content" => "World", "id" => "UG9zdDoxOA==",
"title" => "Hello"}}}}
%Maple.Response{body: %{"createPost" => %{"changedPost" => %{"id" => "UG9zdDoxOA=="}}},
status
```
## Options
The module takes a options from the configuration:
```elixir
config :maple,
build_type_structs: false,
http_adapter: Maple.Clients.Http,
websocket_adapter: Maple.Clients.WebsocketApollo
```
-:buildtype_structs- Default isfalse. If set totruethe macro will create
structs for all the fields found in the introspection query. All types are namespaced intoMaple.Types.-:http_adapter- The default HTTP adapter for completing transactions against the GraphQL
server. Default is: [Maple.Clients.Http](Maple.Clients.Http.html)
-:websocket_adapter- The default Websocket adapter for completing transactions against the GraphQL
server using websockets. Default is: [Maple.Clients.WebsocketApollo`](Maple.Clients.WebsocketApollo.html)
## Installation
elixir
def deps do
[{:maple, git: "https://github.com/maxneuvians/maple"}]
end
or
elixir
def deps do
[{:maple, "~> 0.4.0"}]
end
## Configuration
If you only access one GraphQL API you just need to add the following to you config.exs
elixir
config :maple,
build_type_structs: false,
http_adapter: Maple.Clients.Http,
websocket_adapter: Maple.Clients.WebsocketApollo,
api_url: "URL",
wss_url:, "WSS_URL", # If you are using subscriptions over websockets.
additional_headers: %{"Authorization": "Bearer TOKEN"} # If you have any additional headers
## Ramblings
This library is in development.
Contributions and issues welcome!
__Also if you think this is a terrible idea, please let me know!
## ToDo
- [X] Refactor macro code
- [X] Add proper documentation
- [X] Support subscriptions
- [ ] Support fragments
- [ ] Look into validation through structs
- [ ] Alternative syntax for fields
- [X] Expand help with required attributes
- [X] Expand help with attribute descriptions
## License
MIT
## Version
0.4.0