tiger

Plugin

Tiger bundled with few standard plugins:

• cron: for scheduled tasks,
• http: for http request listeners,
• zmq: for using message queue communication between modules,
• mail: for sending out email.

Plugin details

cron

Literally, cron is a plugin that allows module runs based on a cron expression. it only take effect when you define a module. It doesn’t provide any messages but actually mutates the state.

Attributes

Attributes	Value
Stateless	N
Message	N
Messge Format	{}
define?	Y
notify?	N

Example

define

{
  target: "cron:*/5 * * * * *", 

  process: function ({ count = 0 }) {
    count++;
    return { count }
  }
}

http

http plugin allows you runs on a specific http path on Tiger server. http plugin is stateful and provide both a HTTP request and a response object as message to the module.

Attributes

Attributes	Value
Stateless	N
Message	Y
Messge Format	{ req, res }
define?	Y
notify?	N

Example

define

{
  target: "http:hello", 
  process: function (state, {req, res}) {
    res.send("hello world");
    return state;
  }
}

zmq

zmq plugin creates a set of queues to communicate between modules. You can either create a module follows a queue, or send messages to the queue in any module(with Tiger#notify).

Attributes

Attributes	Value
Stateless	N
Message	Y
Messge Format	what you sent in Tiger#notify
define?	Y
notify?	Y

Example

define

{
  target: "zmq:hello", 
  state: function (state, message) {
    tiger.log(`Message received: ${JSON.stringify(message)}`)
  }
}

notify

this.notify("zmq:hello", { message: "hello, world" })

mail

mail plugin allow you send out email to any known address after configured a email transport.

Here is required configurations:

{
  mail: {
    sender: "email@example.com",
    transport: {
      host: "some.smtp.server.com",
      port: 465,
      secure: true,
      auth: {
        user: "email@example.com",
        pass: "password"
      }
    }
  }
}

Attribute

Attributes	Value
Stateless	Y
Message	Y
Messge Format	{ from, to, subject, text, html }
define?	N
notify?	Y

Example

// `from` and `to` can be omitted since it can be inferred from sender and target.
this.notify("mail:someone@another.com", { 
  subject: "hello", 
  text: "hello world", 
  html: "<p>hello world</p>" 
});

Self-defined Plugins

How plugin works

A plugin is just a function which takes tiger instance as argument and do some dirty work, including but not limited to register a new resolver.

const somePlugin = {
  id: "<plugin id>"
  setup: function(tiger) {
    const resolver = {
      protocol: "<protocol>",
      define(path, module) {
        // do definition work
      },

      notified(path, param, next) {
        // do notification work
      }
    },

    tiger.register(resolver)
  }
}

You can also use Plugin and Resolver interface with TypeScript for better hinting. Also BaseResolver provided an default implementaion for define() and notified() method.

See src/core/example.ts for an example.