dispatcher-middleware

A middleware control flow dispatcher similar to the middleware implementation of routes within expressjs.

Installation

npm install dispatcher-middleware

Usage

Basic Usage

var Dispatcher = require('dispatcher-middleware').Dispatcher;

var dispatcher = new Dispatcher({
      myAction: [middlewareFn1, middlewareFn2, finalFn],
      myAsyncAction: [[asyncMiddlewareFn1, asyncMiddlewareFn2], finalFn]
    });

Middleware Functions

Middleware functions are passed a data object hash and a next function. Middleware functions pass data by appending the data object.

Middleware functions take the format:

function (data, next) {
  data.x = 3;
  next();
}

And the final function call takes the format:

function (data) {
  console.log(data.x); // 3
}

Any function can short circuit the middleware pipe by not calling next().

Middleware functions are synchronous unless nested within an array. (Other than the leading array).

Asynchronous Middleware Functions (order does not matter)

Nested arrays of middleware will run asynchronously.

Example

function asyncMw1(data, next) {
  window.setTimeout(function () {
    data.x = 4;  
    next();
  }, 100);
}

function asyncMw2(data, next) {
  console.log(data.x); // undefined
  data.y = 3;
  next();
}

function final(data) {
  console.log(data.x + data.y); // 7
}

var Dispatcher = require('dispatcher-middleware').Dispatcher;

var dispatcher = new Dispatcher({
      myAction: [[asyncMw1, asyncMw2], final]
    });

Just the Middleware Pipe

var Pipe = require('dispatcher-middleware').Pipe;

new Pipe.execute([middlewareFn1, middlewareFn2, final]);

Contribute

Tests

npm test

Coverage

npm run-script coverage

License

MIT