pagoda

Reusable function stacks for Node.js and the browser.

Example

var pagoda = require('pagoda');

var stack = pagoda.stack(
    function(next) {
        console.log(this.foo);
        this.bar = 'baz';
        next();
    },
    function(next) {
        console.log(this.bar);
        next();
    }
);

stack.handle({ foo: 'bar' });

Usage

Stacks execute an ordered list of functions. To register functions with a stack, you can pass them as arguments to pagoda.stack and/or append a function to the bottom of the stack by calling use:

var stack = pagoda.stack(
    function(next) {
        // first
    },
    function(next) {
        // second
    }
);

stack.use(function(next) {
    // third
});

Each function must accept an argument that, when called, will pass control down to the next function in the stack.

Execute a stack by calling handle and passing an optional context that will be bound to this in all of the functions:

stack.handle(context);

Errors

Errors can be sent down the stack by passing them to next:

function(next) {
    next(new Error());
}

Functions can optionally handle these errors by accepting an additional argument:

function(err, next) {
    if (err) console.log(err.message);
    next();
}

Functions that do not accept an error argument will be skipped when an error propagates down the stack. If an error reaches the bottom of the stack it will be thrown.

Install

npm install pagoda

Tests

To test with Node.js, run:

make test

Test in the browser, open:

test/index.html