ls-cache-js

A library to use localStorage to cache JS modules in modern browsers.

Usage

• define and require modules
• track dependencies
• load js when not cached
• cache js using localStorage

TODO

• localStorage version control and explicitly flushing
• relative path and alias supporting

DEMO

// file: demo-1.html
// init the main routine, requires 3 modules
lsCache(['logger.js', 'demo-1.js', 'demo-2.js'], function(logger, d1, d2){
  logger.log('main is here');
  logger.log('main says d1 = ' + d1);
  logger.log('main says d2 = ' + d2);
});

// file: demo-1.js
// define a module, requires 2 modules
lsCache(['zepto.js', 'logger.js'], function($, logger){
  logger.log('d1 is coming');
  return 'd1';
});

• when demo-1.js is not cached, it will be added as a <script> tag. then it will be cached.
• when it's cached, it will be loaded from localStorage without any other network spending.
• --recursively

HOW DOES THIS WORK?

function lsCache(requires, fn){
  var fnStr = fn.toString(); // get the raw string of the module function
  localStorage['xxx'] = fnStr; // save it to localStorage

  //...

  var fnStr = localStorage['xxx'], // read the string from localStorage
      fn = (new Function('return ' + fnStr))(), // build it into a function
      module = fn(); // call it
}