ordu

Execute functions in a configurable order, modifying a shared data structure.

Task functions are executed in order of addition, and passed a shared context, and a modifiable data structure. Execution is synchronous. You can exit early by returning a non-null value from a task function.

You can tag task functions, and restrict execution to the subset of task functions with matching tags.

This module is used by the Seneca framework to provide configurable extension hooks.

Quick example

var Ordu = require('ordu')

var w = Ordu()

w.add(function first (ctxt, data) {
  if (null == data.foo) {
    return {kind: 'error', why: 'no foo'}
  }

  data.foo = data.foo.substring(0, ctxt.len)
})

w.add({tags: ['upper']}, function second (ctxt, data) {
  data.foo = data.foo.toUpperCase()
})

var ctxt = {len: 3}
var data = {foo: 'green'}

w.process(ctxt, data)
console.log(data.foo) // prints 'GRE' (first, second)

data = {foo: 'blue'}
w.process({tags: ['upper']}, ctxt, data)
console.log(data.foo) // prints 'BLUE' (second)

data = []
var res = w.process(ctxt, data)
console.log(res) // prints {kind: 'error', why: 'no foo', ... introspection ...}

Install

npm install ordu

Notes

From the Irish ordú: instruction. Pronounced or-doo.

License

Copyright (c) 2014-2020, Richard Rodger and other contributors. Licensed under MIT.