====== Collection class ======

The primary purpose of this class is to keep a number of Datarecords bundled together. In addition to convenience, this can also speed things up when using the reference-fields in the Datarecord class as information for all contained Datarecord objects can be queried at the same time.

===== Basic usage =====

Usually the Collection is the result of using the [[filter_class|Filter]] object, but it can be spawned on its own, passing a Datarecord or an array of Datarecords into the constructor, or adding it later using the add function.

<code php>
$collection = new Collection($user);
$collection->add($another_user);
</code>

A datarecord can only contain objects of the same type and will adapt to the first object it receives. 

The collection can be sorted by a specific field using ''sort'' and implements the PHP Iterator interface, so it can be used like any iterator:

<code php>
$collection->sort('full_name');
foreach ($collection as $user) {
    echo $user->full_name;
}
</code>

There are also some more sofisticated get-functions such as getting the value of a single field from the objects in the collection

<code php>
foreach ($collection->getAllFullValues('full_name') as $value) {
   echo $value;
}
</code>