isotope/_posts/docs/2010-12-07-sorting.mdown

---

title: Sorting
category: docs
layout: doc
related: sorting

---

Isotope can rearrange item elements via sorting.

[**See Demo: Sorting**](../demos/sorting.html)

## Markup

In our example, each item element has several data points that can be used for sorting. There's the elemental symbol, number, name of the element, weight, and category.


{% highlight html %}

<div id="demo">
  <div class="element transition metal" data-category="transition"> 
    <p class="number">79</p> 
    <h3 class="symbol">Au</h3> 
    <h2 class="name">Gold</h2> 
    <p class="weight">196.966569</p> 
  </div> 
    
  <div class="element metalloid" data-category="metalloid"> 
    <p class="number">51</p> 
    <h3 class="symbol">Sb</h3> 
    <h2 class="name">Antimony</h2> 
    <p class="weight">121.76</p> 
  </div>
</div>

{% endhighlight %}


## getSortData

In order to extract this data from the element, we need to pass in a function to get it via the `getSortData` option.  This option accepts an object, whose values are the functions to extract the data.

Each function receives one argument, which represents a jQuery object for each item element. With that argument, the function needs to return the data point.

In the example above, to get element name, we would need to get the text from the `.name` element. The same works for symbol.

{% highlight javascript %}

$('#demo').isotope({
  getSortData : {
    name : function ( $elem ) {
      return $elem.find('.name').text();
    },
    symbol : function ( $elem ) {
      return $elem.find('.symbol').text();
    }
  }
});

{% endhighlight %}


For numerical data, we can convert a text value into a number via `parseInt()` function.

{% highlight javascript %}

getSortData : {
  // ...
  number : function ( $elem ) {
    return parseInt( $elem.find('.name').text(), 10 );
  },
  weight : function ( $elem ) {
    return parseInt( $elem.find('.weight').text(), 10 );
  }
}

{% endhighlight %}

The data extracted can be anything accessible in the item element via jQuery. To extract the category data, we can use the `.attr()`.

{% highlight javascript %}

getSortData : {
  // ...
  category : function ( $elem ) {
    return $elem.attr('data-category');
  }
}

{% endhighlight %}

## sortBy

For every method set in `getSortData`, Isotope uses that method to build the data for sorting. The data cache is built on initialization so it can be quickly accessed when sorting. With the methods above, we have built data for an item elements name, symbol, number, weight and category.

Sorting elements is done with the `sortBy` option. The value needs to match the property name used in the `getSortData` object.

With our example, we can use `'name'`, `'symbol'`, `'number'`, `'weight'` and `'category'`.

{% highlight javascript %}

$('#demo').isotope({ sortBy : 'symbol' });

{% endhighlight %}

There is an additional sorting data built in to Isotope `'original-order'`. Sorting with `'original-order'` will use the original order of the item elements to arrange them in the layout.

## sortAscending

By default, Isotope sorts data in ascension. If our data for name is "Gold, Antimony, Lead, Iron, Silver", when sorted by name, the elements will be ordered ABC.. : "Antimony, Gold, Iron, Lead, Silver."  To reverse the order and sort data in descension, set the `sortAscending` option to `false`.

{% highlight javascript %}

$('#demo').isotope({ 
  sortBy : 'name',
  sortAscending : false
});

{% endhighlight %}

## Buttons

We can use a simple list for our buttons.

{% highlight html %}

<ul id="sort">
  <li><a href="#name">name</a></li>
  <li><a href="#symbol">symbol</a></li>
  <li><a href="#number">number</a></li>
  <li><a href="#weight">weight</a></li>
  <li><a href="#category">category</a></li>
</ul>

{% endhighlight %}

When one of these links is clicked, we can use the `href` attribute as the value for `sortBy` in the Isotope script.

{% highlight javascript %}

$('#sort a').click(function(){
  // get href attribute, minus the '#'
  var sortName = $(this).attr('href').slice(1);
  $('#demo').isotope({ sortBy : sortName });
  return false;
});

{% endhighlight %}