title: Filter array dynamically based off 3 NSPredicates
body: <p>I have a NSMutableArray of NSDictionaries. I would like to be able to filter dynamically.</p>
  
  <p>For example, I have 3 types of filters</p>
  
  <pre><code>- area
  - item
  - type
  </code></pre>
  
  <p>if area is chossen then I would like to filter the Array with the area predicate, However if the user then chooses to filter item too, the currently filtered area array will then have the item filter applied too it.</p>
  
  <p>However if the area filter is removed then I would like to show the new item filter.</p>
  
  <p>It gets even more complicated when type is introduced, however I am struggling to get this to work correctly and don't really know where to start with the logic of it. </p>
  
  <p>I can get the array to filter based off the last selected predicate. So if I choose area then items the current filter will only be items not both.</p>