globals.define(key, value[, cache])

Defines a new global called key, who's value defaults to value.

The following example defines the global key's default value to the window object:

globals.define('global', window);
globals.getKeyValue('window') //-> window

If a function is provided and cache is falsy, that function is run every time the key value is read:

globals.define('isBrowserWindow', function() {
  console.log('EVALUATING')
  return typeof window !== 'undefined' &&
    typeof document !== 'undefined' && typeof SimpleDOM === 'undefined'
}, false);
globals.get('isBrowserWindow') // logs 'EVALUATING'
                               // -> true
globals.get('isBrowserWindow') // logs 'EVALUATING' again
                               // -> true

If a function is provided and cache is truthy, that function is run only the first time the value is read:

globals.define('isWebkit', function() {
  console.log('EVALUATING')
  var div = document.createElement('div')
  return 'WebkitTransition' in div.style
})
globals.getKeyValue('isWebkit') // logs 'EVALUATING'
                                   // -> true
globals.getKeyValue('isWebkit') // Does NOT log again!
                                   // -> true