Messages

We use an internal system of messages, which are serialized and deserialized from a class that implements everything we could internally need for a message. Messages are meant to be serialized and then passed through the chrome message system.

Types

UnknownPayload

This is a type, and is not accessible at runtime. UnknownPayload describes any Payload.

UnknownMessage

This is a type, and is not accessible at runtime. UnknownPayload describes any Message.

SerializedMessage

This is an interface, and is not accessible at runtime.

A SerializedMessage contains three properties:

1. sender
   • The exact same as Message.prototype.sender.
2. target
   • The exact same as Message.prototype.target.
3. payload
   • Message.prototype.code merged with Message.prototype.payload, with preference to the code.

UnknownSerializedMessage

This is a type, and is not accessible at runtime. UnknownSerializedMessage is a SerializedMessage of any Message.

Message

The Message class implements everything needed to use messages properly. The C property is the code of the message, and is used to narrow the code and payload properties.

constructor(sender, target, code, payload)

• sender <number> The ID of the message's sender.
• target <number> The ID of the message's intended recipient.
• code <payloadCodeUnion> The code of the message.
• payload <Payload> The message's payload, excluding the code.

Creates a new Message instance. If you are looking to create a message instance from an unknown input or a known serialized message, use Message.fromObject instead.

const msg = new Message(-1, 3, "0000", { content: "test" });

Message.fromObject(obj)

• obj <unknown> The input to create the Message from. Can be anything, as it will be filtered as needed.
• Returns <Message | null> Either a Message instance, or null if a Message instance could not be created from the input.

The Message.fromObject() static method creates an instance of the Message class from an input. The function was built to receive a SerializedMessage that can also have extra parameters. Any other inputs will cause the function to return null.

const { fromObject } = Message;

// all of these return null
fromObject(3);
fromObject(new SomeClass());
fromObject(null);
fromObject(undefined);
fromObject({
  hello: "there",
});

// these will return a Message object
fromObject(someMessage.serialize());
fromObject({
  sender: 0,
  target: 1,
  payload: {
    code: "0000",
  },
  extra: "prop",
});
fromObject({
  sender: 0,
  target: 1,
  payload: {
    code: "0000",
  },
});

Message.prototype.sender

Message.prototype.sender is a getter. It exposes the internal _sender field. The sender field is the ID of the message's sender.

Message.prototype.target

Message.prototype.target is a getter. It exposes the internal _target field. The target field is the ID of the message's intended recipient.

Message.prototype.code

Message.prototype.code is a getter. It exposes the internal _code field. The code field is the code of the message.

Message.prototype.payload

Message.prototype.payload is a getter. It exposes the internal _payload field. The payload field is the message's payload, excluding the code.

Message.prototype.serialize()

• Returns <SerializedMessage> The serialized message, ready to be passed to chrome.

Serializes the message, turning it into an object to be passed to chrome.

The serialized message can be deserialized by Message.fromObject.

msg.serialize(); // { sender: 0, target: 1, payload: { code: "0000", content: "test" } }

Message.prototype.createResponse(code, payload)

• code <payloadCodeUnion> The code of the response.
• payload <Payload> The payload of the response.

Creates a response to the message, with the given code and payload.

msg.serialize(); // { sender: 0, target: 1, payload: { code: "0000", content: "test" } }
const resp = msg.createResponse("0000", { content: "response " });
resp.serialize(); // { sender: 1, target: 0, payload: { code: "0000", content: "response" } }