Convert javascript dot notation object to nested object

I believe this is what you're after:

function deepen(obj) {
  const result = {};

  // For each object path (property key) in the object
  for (const objectPath in obj) {
    // Split path into component parts
    const parts = objectPath.split('.');

    // Create sub-objects along path as needed
    let target = result;
    while (parts.length > 1) {
      const part = parts.shift();
      target = target[part] = target[part] || {};
    }

    // Set value at end of path
    target[parts[0]] = obj[objectPath]
  }

  return result;
}

// For example ...
console.log(deepen({
  'ab.cd.e': 'foo',
  'ab.cd.f': 'bar',
  'ab.g': 'foo2'
}));

If you're using Node.js (e.g. - if not cut and paste out of our module), try this package: https://www.npmjs.org/package/dataobject-parser

Built a module that does the forward/reverse operations:

https://github.com/Gigzolo/dataobject-parser

It's designed as a self managed object right now. Used by instantiating an instance of DataObjectParser.

var structured = DataObjectParser.transpose({
    'ab.cd.e' : 'foo',
    'ab.cd.f' : 'bar',
    'ab.g' : 'foo2'
});                                                                                                                                                                                                                                                                                                                                                                                                                                                   

structured.data() returns your nested object:

{ab: {cd: {e:'foo', f:'bar'}, g:'foo2'}}

So here's a working example in JSFiddle:

http://jsfiddle.net/H8Cqx/

Function name is terrible and the code was quickly made, but it should work. Note that this modifies the original object, I am not sure if you wanted to create a new object that is expanded version of the old one.

(function(){

    function parseDotNotation( str, val, obj ){
    var currentObj = obj,
        keys = str.split("."), i, l = keys.length - 1, key;

        for( i = 0; i < l; ++i ) {
        key = keys[i];
        currentObj[key] = currentObj[key] || {};
        currentObj = currentObj[key];
        }

    currentObj[keys[i]] = val;
    delete obj[str];
    }

    Object.expand = function( obj ) {

        for( var key in obj ) {
        parseDotNotation( key, obj[key], obj );
        }
    return obj;
    };

})();



var expanded = Object.expand({
    'ab.cd.e' : 'foo',
        'ab.cd.f' : 'bar',
    'ab.g' : 'foo2'
});



JSON.stringify( expanded );  


//"{"ab":{"cd":{"e":"foo","f":"bar"},"g":"foo2"}}"