You must be precise in your references (e.g. listTodo not listTodos)
It's a good idea to follow the existing examples closely as you "boot" into a new topic.
I encourage you to:
- Add
package something; to your todo.proto
- Conventionally (!)
protos should be shared between clients and servers
So...
- Move
todo.proto to its own directory e.g. protos
.
├── client
├── protos
└── server
In todo.proto:
syntax="proto3"; //indicates we are using proto version 3
// Use a more applicable name
package foo;
service TodoService{ //we can define API contract too, in the protocol buffer
rpc CreateTodo (Todo) returns (Todo) {}
rpc GetTodo (TodoRequest) returns (Todo) {}
rpc ListTodo (Empty) returns (TodoList) {}
}
message Empty {}
message Todo{
string id=1; //field numbers are used to identify fields in binary encoded data
string title=2;
optional string content=3;
}
message TodoList{
repeated Todo todos=1; //repeated field indicates that there would be an array of ToDos coming in
}
message TodoRequest{
string id=1; // the REST equivalent of this would be /todos/:id (resource based ) vs action based
}
server/index.js:
const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');
const packageDefinition = protoLoader.loadSync('../protos/todo.proto', {
keepCase: true,
longs: String,
enums: String,
defaults: true,
oneofs: true
});
const protoDescriptor = grpc.loadPackageDefinition(packageDefinition);
// The suffix is the package name
var todoService = protoDescriptor.foo;
const server = new grpc.Server();
const todos = [{
id: '1',
title: 'Todo1',
content: 'Content of todo 1'
},
{
id: '2',
title: 'Todo2',
content: 'Content of todo 2'
}
];
// todoService = protoDescriptor.foo
// TodoService is the name of the gRPC service
server.addService(todoService.TodoService.service, {
// below I am defining the RPCs
// Your RPC is called `listTodo`
listTodo: (call, callback) => {
callback(null, { todos: todos }); // error first callback, as error is null
},
createTodo: (call, callback) => {
let incomingNewTodo = call.request;
todos.push(incomingNewTodo);
callback(null, incomingNewTodo);
},
getTodo: (call, callback) => {
let incomingRequest = call.request;
let todoId = incomingRequest.id;
const response = todos.filter((todo) => todo.id == todoId);
if (response.length > 0) {
callback(null, response);
} else {
callback({
message: 'Todo not found'
}, null);
}
}
});
server.bindAsync('localhost:50051', grpc.ServerCredentials.createInsecure(), () => {
console.log("Server started")
server.start();
});
And:
client/index.js:
const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');
const packageDefinition = protoLoader.loadSync('../protos/todo.proto', {
keepCase: true,
longs: String,
enums: String,
defaults: true,
oneofs: true
});
const protoDescriptor = grpc.loadPackageDefinition(packageDefinition);
const todoService = protoDescriptor.foo;
const client = new todoService.TodoService('localhost:50051', grpc.credentials.createInsecure());
client.listTodo({}, (err, response) => {
if (err) {
console.error(err);
return;
}
console.log(response);
});
And when running:
{
todos: [
{
id: '1',
title: 'Todo1',
content: 'Content of todo 1',
_content: 'content'
},
{
id: '2',
title: 'Todo2',
content: 'Content of todo 2',
_content: 'content'
}
]
}
