Siren in Protobuffers v3.

order.json

{
  "class": [ "order" ],
  "properties": { 
      "orderNumber": 42, 
      "itemCount": 3,
      "status": "pending"
  },
  "entities": [
    { 
      "class": [ "items", "collection" ], 
      "rel": [ "http://x.io/rels/order-items" ], 
      "href": "http://api.x.io/orders/42/items"
    },
    {
      "class": [ "info", "customer" ],
      "rel": [ "http://x.io/rels/customer" ], 
      "properties": { 
        "customerId": "pj123",
        "name": "Peter Joseph"
      },
      "links": [
        { "rel": [ "self" ], "href": "http://api.x.io/customers/pj123" }
      ]
    }
  ],
  "actions": [
    {
      "name": "add-item",
      "title": "Add Item",
      "method": "POST",
      "href": "http://api.x.io/orders/42/items",
      "type": "application/x-www-form-urlencoded",
      "fields": [
        { "name": "orderNumber", "type": "hidden", "value": "42" },
        { "name": "productCode", "type": "text" },
        { "name": "quantity", "type": "number" }
      ]
    }
  ],
  "links": [
    { "rel": [ "self" ], "href": "http://api.x.io/orders/42" },
    { "rel": [ "previous" ], "href": "http://api.x.io/orders/41" },
    { "rel": [ "next" ], "href": "http://api.x.io/orders/43" }
  ]
}

order.proto

syntax = "proto3";

package siren.example;

message Order {
  message Properties {
    int32 order_number = 1;
    int32 order_count = 2;
    string status = 3;
  }

  message CustomerSubEntity {
    message Properties {
      string customer_id = 1;
      string name = 2;
    }
  }
}

siren.proto

syntax = "proto3";

package siren;

// http://schema.sirenspec.org/protobuf/siren.Entity
message Entity {
  repeated string class = 1;
  bytes properties = 2;
  repeated AnySubEntity entities = 3;
  repeated Action actions = 4;
  repeated Link links = 5;
}

// http://schema.sirenspec.org/protobuf/siren.AnySubEntity
message AnySubEntity {
  Type type = 1;
  bytes value = 2;

  // http://schema.sirenspec.org/protobuf/siren.AnySubEntity.Type
  enum Type {
    EMBEDDED = 0;
    LINKED = 1;
  }
}

// http://schema.sirenspec.org/protobuf/siren.Link
message Link {
  repeated string class = 1;
  repeated string rel = 2;
  string href = 3;
  string title = 4;
  string type = 5;
}

// http://schema.sirenspec.org/protobuf/siren.LinkedEntity
message LinkedEntity {
  repeated string class = 1;
  repeated string rel = 2;
  string href = 3;
  string title = 4;
}

// http://schema.sirenspec.org/protobuf/siren.Action
message Action {
  repeated string class = 1;
  string name = 2;
  string title = 3;
  string method = 4;
  string href = 5;
  string type = 6;
  repeated Field fields = 7;
}

// http://schema.sirenspec.org/protobuf/siren.Field
message Field {
  string name = 1;
  Type type = 2;
  bytes value = 3;

  // http://schema.sirenspec.org/protobuf/siren.Field.Type
  enum Type {
    TEXT = 0;
    HIDDEN = 1;
    SEARCH = 2;
    TEL = 3;
    URL = 4;
    EMAIL = 5;
    PASSWORD = 6;
    DATETIME = 7;
    DATE = 8;
    MONTH = 9;
    WEEK = 10;
    TIME = 11;
    DATETIME_LOCAL = 12;
    NUMBER = 13;
    RANGE = 14;
    COLOR = 15;
    CHECKBOX = 16;
    RADIO = 17;
    FILE = 18;
  }
}

test.js

var zlib = require('zlib');
var ProtoBuf = require('protobufjs');
var Enum = ProtoBuf.Reflect.Enum;

var builder = ProtoBuf.newBuilder({ convertFieldsToCamelCase: true });
ProtoBuf.loadProtoFile('./order.proto', builder);
ProtoBuf.loadProtoFile('./siren.proto', builder);

var Siren = builder.build('siren');
var SirenExample = builder.build('siren.example');

var json = require('./order.json');

var Order = SirenExample.Order;

var order = new Siren.Entity({
  class: ['order'],
  properties: new Order.Properties({
      orderNumber: 42,
      orderCount: 3,
      status: 'pending'
  }).toBuffer(),
  entities: [
    new Siren.AnySubEntity({
      type: 'EMBEDDED',
      value: new Siren.Entity({
        class: ['customer', 'info'],
        properties: new Order.CustomerSubEntity.Properties({
            customerId: 'pj123',
            name: 'Peter Joseph'
        }).toBuffer(),
        links: [
          new Siren.Link({
            rel: ['self'],
            href: 'http://api.x.io/customers/pj123'
          })
        ]
      }).toBuffer()
    }),
    new Siren.AnySubEntity({
      type: 'LINKED',
      value: new Siren.LinkedEntity({
        class: ['items', 'collection'],
        rel: ['http://x.io/rels/order-items'],
        href: 'http://api.x.io/orders/42/items'
      }).toBuffer()
    })
  ],
  actions: [
    new Siren.Action({
      name: 'add-item',
      method: 'POST',
      href: 'http://api.x.io/orders/42/items',
      type: 'application/x-www-form-urlencoded',
      title: 'Add Item',
      fields: [
        new Siren.Field({
          name: 'orderNumber',
          type: 'HIDDEN',
          value: new Buffer('42')
        }),
        new Siren.Field({
          name: 'productCode',
          type: 'TEXT'
        }),
        new Siren.Field({
          name: 'quantity',
          type: 'NUMBER'
        })
      ]
    })
  ],
  links: [
    new Siren.Link({
      rel: ['self'],
      href: 'http://api.x.io/orders/42'
    }),
    new Siren.Link({
      rel: ['previous'],
      href: 'http://api.x.io/orders/41'
    }),
    new Siren.Link({
      rel: ['next'],
      href: 'http://api.x.io/orders/43'
    })
  ]
});

var jsonBuffer = new Buffer(JSON.stringify(json));
var protoBuffer = order.toBuffer();

var stringified = JSON.stringify(json);

console.log('json:', jsonBuffer.length);
console.log('proto:', protoBuffer.length);
console.log('json-gzip:', zlib.gzipSync(jsonBuffer).length);
console.log('proto-gzip:', zlib.gzipSync(protoBuffer).length);

var decoded = Siren.Entity.decode(protoBuffer);
if (decoded.class.indexOf('order') > -1) {
  var fieldValue = decoded.actions[0].fields[0].value;
  console.log(fieldValue.toString('utf8'));

  decoded.entities.forEach(function(subEntity) {
    if (subEntity.type === Siren.AnySubEntity.Type.EMBEDDED) {
      var e = Siren.Entity.decode(subEntity.value);
      if (e.class.indexOf('customer') > -1 && e.class.indexOf('info') > -1) {
        var props = SirenExample.Order.CustomerSubEntity.Properties.decode(e.properties);
        console.log(props.name);
      }
    }
  });
}

var fs = require('fs');
var writeStream = fs.createWriteStream('./Protobuffun/Protobuffun/bin/Debug/protobuf.dat');

writeStream.end(protoBuffer);

writeStream.on('finish', function() {
  var file = fs.readFileSync('./Protobuffun/Protobuffun/bin/Debug/protobuf.dat');
  var root = Siren.Entity.decode(file);
  if (root.class.indexOf('order') > -1) {
    var props = SirenExample.Order.Properties.decode(root.properties);
    console.log(props);
  }
});