myservice.proto

// This is the public API offered by the shopping cart entity.
syntax = "proto3";

import "google/protobuf/empty.proto";
import "cloudstate/entity_key.proto";
import "cloudstate/eventing.proto";
import "google/api/annotations.proto";

// Change this package name to be your organization and project name.
package com.example.myservice;

// A command to Add an Item.  
// Note the use of the cloudstate.entity_key field option extension, 
// this is used to indicate which field(s) form the entity key, which 
// the Akka backend will use to identify entities and shard them
// (in this example  `user_id` ).
// is what will be used as the unique entity key.  The other fields 
// contain data that we want to store in that entity.
message MyAddItem {
    string user_id = 1 [(.cloudstate.entity_key) = true];
    string id = 2;
    string name = 3;
    int32 quantity = 4;
}

// A command to Remove an Item.  The first property `user_id` 
// is what will be used to form the entity key.  The second field 
// is used to lookup the item that we want to remove.
message MyRemoveItem {
    string user_id = 1 [(.cloudstate.entity_key) = true];
    string id = 2;
}


// A command to Get the currect state of an entity.
// We again pass in the entity key in order to be able to lookup 
// our entity.
message MyGetState {
    string user_id = 1 [(.cloudstate.entity_key) = true];
}

// This type is our data Item that we store in our state.
// Change this item to reflect your own model.
message MyItem {
    string id = 1;
    string name = 2;
    int32 quantity = 3;
}

// The enitty state is represented as a list of the above data items.
// You should edit this so that it reflects your own state.
message MyState {
    repeated MyItem items = 1;
}

// This is the actual service definition.  We will use these methods 
// to handle data coming in and going out of our service.  In an event
// sourced service like this one, calls usually reflect the commands that 
// we have defined above. 
service MyService {
    // The call to add an item to our entity.  Additionally we provide a 
    // named http endpoint.  To see how you might use this endpoint you 
    // must first understand the route.yaml file in the deploy folder.
    rpc AddItem(MyAddItem) returns (google.protobuf.Empty) {
        // option (google.api.http) specifies that this method is a gRPC HTTP mapping annotation
        // for more info see: https://cloud.google.com/endpoints/docs/grpc/transcoding
        option (google.api.http) = {
            post: "/state/{user_id}/items/add",
            body: "*",
        };        
    }

    // Call to remove an item from our entity.
    rpc RemoveItem(MyRemoveItem) returns (google.protobuf.Empty) {
        // option (google.api.http) specifies that this method is a gRPC HTTP mapping annotation
        // for more info see: https://cloud.google.com/endpoints/docs/grpc/transcoding
        option (google.api.http).post = "/state/{user_id}/items/{id}/remove";
    }

    // Call to return the state from an entity.
    rpc GetState(MyGetState) returns (MyState) {
        // option (google.api.http) specifies that this method is a gRPC HTTP mapping annotation
        // for more info see: https://cloud.google.com/endpoints/docs/grpc/transcoding
        option (google.api.http) = {
          get: "/state/{user_id}",
          additional_bindings: {
            get: "/state/{user_id}/items",
            response_body: "items"
          }
        };
    }
}