Backbone.js & Underscore.js Natural Sorting

README.md

Backbone.js & Underscore.js Natural Sorting Algorithm

Backbone is great but I continually found the default sorting method limited due to the following:

Disc 1, Disc 2, … Disc 10 would become Disc 1, Disc 10, Disc 2

With the help of Jim Palmer's naturalSort.js, I was able to integrate natrual sorting into Backbone.Collection.

Backbone collections are automatically sorted and now, by simply adding sortType:"natural", your collections can be sorted naturally.

// unsorted data
var data = [
	{label: 'Disc 1'}, 
	{label: 'Disc 2'}, 
	{label: 'Disc 10'}, 
	{label: 'Disc 3'},
	{label: 'Disc 11'}
];

var Collection = Backbone.Collection.extend({
	comparator: function(m){
		return m.get('label');
	}
});
	
var NatrualCollection = Backbone.Collection.extend({
	sortType: 'natural',
	comparator: function(m){
		return m.get('label');
	}
});

var coll = new Collection(data);
var collNat = new NatrualCollection(data);

console.log('Not sorted naturally', coll.pluck('label'));
console.log('Sorted naturall', collNat.pluck('label'));

Underscore and Vanilla JS

An underscore.js method is also available

var sorted = _.sortByNat(data, function(m){ return m.label });

console.log(_.pluck(sorted, 'label'));

Lastly, natural sort can be called directly on an Array

["Disc 1", "Disc 2", "Disc 10", "Disc 3", "Disc 11"].sortNat();

backbone.naturalsort.js

/*
* Backbone.js & Underscore.js Natural Sorting
*
* @author Kevin Jantzer <https://gist.github.com/kjantzer/7027717>
* @since 2013-10-17
* 
* NOTE: make sure to include the Natural Sort algorithm by Jim Palmer (https://github.com/overset/javascript-natural-sort)
*/

// add _.sortByNat() method
_.mixin({

	sortByNat: function(obj, value, context) {
	    var iterator = _.isFunction(value) ? value : function(obj){ return obj[value]; };
	    return _.pluck(_.map(obj, function(value, index, list) {
	      return {
	        value: value,
	        index: index,
	        criteria: iterator.call(context, value, index, list)
	      };
	    }).sort(function(left, right) {
	      var a = left.criteria;
	      var b = right.criteria;
	      return naturalSort(a, b);
	    }), 'value');
	}
});


// add _.sortByNat to Backbone.Collection
Backbone.Collection.prototype.sortByNat = function(value, context) {
  var iterator = _.isFunction(value) ? value : function(model) {
    return model.get(value);
  };
  return _.sortByNat(this.models, iterator, context);
};

// new Natural Sort method on Backbone.Collection
Backbone.Collection.prototype.sortNat = function(options) {
  if (!this.comparator) throw new Error('Cannot sortNat a set without a comparator');
  options || (options = {});

  if (_.isString(this.comparator) || this.comparator.length === 1) {
    this.models = this.sortByNat(this.comparator, this);
  } else {
    this.models.sortNat(_.bind(this.comparator, this));
  }

  if (!options.silent) this.trigger('sort', this, options);
  return this;
};

// save the oringal sorting method
Backbone.Collection.prototype._sort = Backbone.Collection.prototype.sort;

// override the default sort method to determine if "regular" or "natural" sorting should be used
Backbone.Collection.prototype.sort = function(){
	
	if( this.sortType && this.sortType === 'natural' )
		Backbone.Collection.prototype.sortNat.apply(this, arguments);
	else
		Backbone.Collection.prototype._sort.apply(this, arguments);
};

naturalSort.js

/*
* Natural Sort algorithm for Javascript - Version 0.7 - Released under MIT license
* Author: Jim Palmer (based on chunking idea from Dave Koelle)
* https://github.com/overset/javascript-natural-sort
*/
function naturalSort (a, b) {
    var re = /(^-?[0-9]+(\.?[0-9]*)[df]?e?[0-9]?$|^0x[0-9a-f]+$|[0-9]+)/gi,
        sre = /(^[ ]*|[ ]*$)/g,
        dre = /(^([\w ]+,?[\w ]+)?[\w ]+,?[\w ]+\d+:\d+(:\d+)?[\w ]?|^\d{1,4}[\/\-]\d{1,4}[\/\-]\d{1,4}|^\w+, \w+ \d+, \d{4})/,
        hre = /^0x[0-9a-f]+$/i,
        ore = /^0/,
        i = function(s) { return naturalSort.insensitive && (''+s).toLowerCase() || ''+s },
        // convert all to strings strip whitespace
        x = i(a).replace(sre, '') || '',
        y = i(b).replace(sre, '') || '',
        // chunk/tokenize
        xN = x.replace(re, '\0$1\0').replace(/\0$/,'').replace(/^\0/,'').split('\0'),
        yN = y.replace(re, '\0$1\0').replace(/\0$/,'').replace(/^\0/,'').split('\0'),
        // numeric, hex or date detection
        xD = parseInt(x.match(hre)) || (xN.length != 1 && x.match(dre) && Date.parse(x)),
        yD = parseInt(y.match(hre)) || xD && y.match(dre) && Date.parse(y) || null,
        oFxNcL, oFyNcL;
    // first try and sort Hex codes or Dates
    if (yD)
        if ( xD < yD ) return -1;
        else if ( xD > yD ) return 1;
    // natural sorting through split numeric strings and default strings
    for(var cLoc=0, numS=Math.max(xN.length, yN.length); cLoc < numS; cLoc++) {
        // find floats not starting with '0', string or 0 if not defined (Clint Priest)
        oFxNcL = !(xN[cLoc] || '').match(ore) && parseFloat(xN[cLoc]) || xN[cLoc] || 0;
        oFyNcL = !(yN[cLoc] || '').match(ore) && parseFloat(yN[cLoc]) || yN[cLoc] || 0;
        // handle numeric vs string comparison - number < string - (Kyle Adams)
        if (isNaN(oFxNcL) !== isNaN(oFyNcL)) { return (isNaN(oFxNcL)) ? 1 : -1; }
        // rely on string comparison if different types - i.e. '02' < 2 != '02' < '2'
        else if (typeof oFxNcL !== typeof oFyNcL) {
            oFxNcL += '';
            oFyNcL += '';
        }
        if (oFxNcL < oFyNcL) return -1;
        if (oFxNcL > oFyNcL) return 1;
    }
    return 0;
}

// extend Array to have a natural sort
Array.prototype.sortNat = function(){
	return Array.prototype.sort.call(this, naturalSort)
}