handle-node

Simple callback delegator based on DOM Node type.

Provides an alternative to switches, numeric constant-based delegation, and DOM NodeIterators or TreeWalkers.

Installation

With ESM bundler (e.g., Rollup)

import handleNode from 'handle-node';

Node

npm install handle-node

const handleNode = require('handle-node');

Browser (any)

<script src="handle-node/dist/index-umd.js"></script>

Browser (ESM - modern browsers only)

<script type="module">
import handleNode from './node_modules/handle-node/dist/index-esm.js';
 
</script> 

Usage

Supply a node followed by a handler object whose all optional properties (human-readable Node type names) should be set to a callback which will be passed the supplied Node and, always as the last argument, a reference to the object on which the callbacks exist. The return value will be undefined if a handler is missing, but otherwise will be the result of invoking the callback which corresponds to the supplied node's type.

Here is a demonstration reimplementing textContent (if only element and text types are known to be present):

const textContent = handleNode(node, { // This object is `textSerializer`
  element ({childNodes}, textSerializer) {
    return [...childNodes].reduce((str, node) => {
      return str + handleNode(node, textSerializer);
    }, '');
  },
  text: ({nodeValue}) => nodeValue
});

Other arguments can also be passed in after node and before the handler object, and these will also be supplied to the callbacks:

const textContent = handleNode(
  node, arg1, arg2,
  { // This object is `textSerializer`
    element ({childNodes}, arg1, arg2, textSerializer) {
      return [...childNodes].reduce((str, node) => {
        return str + handleNode(node, arg1, arg2, textSerializer);
      }, '');
    },
    text: ({nodeValue}, arg1, arg2) => nodeValue
  }
);

API

The handler object can take the following optional properties:

• element
• attribute
• text
• cdata
• entityReference
• entity
• processingInstruction
• comment
• document
• documentType
• documentFragment
• notation