phx_server

PhxServer

This example demonstrates how to use JsonRPC with a websocket and with a HTTP API in a phoenix app.

The PhxServerWeb.JsonRPCSocket websocket implementation follows the example you can find in the phoenix documentation for Phoenix.Socket.Transport.

The API controller can be found in PhxServerWeb.API.JsonRpcController.

The RPC functions can be found in PhxServer.RemoteProcedureCalls.

To start your Phoenix server:

• Install dependencies with mix deps.get
• Install Node.js dependencies with npm install inside the assets directory
• Start Phoenix endpoint with mix phx.server

Now you can visit localhost:4000 from your browser.

• The wesocket endpoint: ws://localhost:4000/rpc/websocket
• The API endpoint: http://localhost:4000/api/rpc

Using the example ...

Starting the server:

iex -S mix phx.server

... via a websocket

Open the javascript console in your browser and connect to the RPC websocket:

> ws = new WebSocket("ws://localhost:4000/rpc/websocket")

Setup the onmessage callback:

> ws.onmessage = (response) => console.log(JSON.parse(response.data))

Send an RPCs to the server:

> ws.send(JSON.stringify({id: 1, jsonrpc: "2.0", method: "add", params: [1, 2]}))
< {id: 1, jsronrpc: "2.0", result: 3}
> ws.send(JSON.stringify({id: 2, jsonrpc: "2.0", method: "divide", params: [4, 2]}))
< {id: 2, jsronrpc: "2.0", result: 2}
> ws.send(JSON.stringify({id: 3, jsonrpc: "2.0", method: "divide", params: [4, 0]}))
< {id: 3, jsronrpc: "2.0", error: {code: -32001, message: "division by zero"}}
> ws.send(JSON.stringify({id: 4, jsonrpc: "2.0", method: "divide", params: [4, 0]}))
< {id: 4, jsronrpc: "2.0", error: {code: -32000, message: "Internal server error"}}
> ws.send(JSON.stringify({jsonrpc: "2.0", method: "say", params: ["hello"]}))

Take a look into the iex session:

[info] handle_in:
json: %{"id" => 1, "method" => "add", "params" => [1, 2]}
opts: [opcode: :text]
[info] response: {"id":1,"jsonrpc":"2.0","result":3}
...
[info] say: hello

... via http

The repo contains some scripts using curl to call the RPCs.

$> add.sh 1 2
HTTP/1.1 200 OK
{
   "id" : 1625412051,
   "jsonrpc" : "2.0",
   "result" : 3
}

$> divide.sh 5 2
HTTP/1.1 200 OK
{
   "id" : 1625412563,
   "jsonrpc" : "2.0",
   "result" : 2
}
$> divide.sh 5 0
HTTP/1.1 200 OK
{
   "error" : {
      "code" : -32001,
      "message" : "division by zero"
   },
   "id" : 1626719527,
   "jsonrpc" : "2.0"
}

$> ./say.sh hello
HTTP/1.1 204 No Content