// Create a new chain that will allow us to attach nodes to it.
$Chain = new \Parcel\Chain\Chain();
 
// Add a new node to the chain which will add a string to the dispatcher.
$Chain->LinkNode(new \Parcel\Chain\Nodes\AddStringNode([
    'Key' => 'Name',
    'Value' => 'Hello World'
]));
 
// Adds another node which will echo the previously created string.
$Chain->LinkNode(new \Parcel\Chain\Nodes\EchoStringNode([
    'Key' => 'Name'
]));
 
// Instantiate a new dispatcher which will be sent to every node.
$Dispatch = new \Parcel\Chain\Dispatch\Dispatch($Chain);
 
// We start the node execution, which sends the dispatcher to all the nodes.
// The end result will be the value 'Hello World' printed to the screen.
$Chain->Execute($Dispatch);

<?php
 
namespace Parcel\Chain\Nodes;
 
use Parcel\Chain\DispatchInterface;
use Parcel\Chain\NodeBase;
 
class AddStringNode extends NodeBase {
 
    /**
     * This is the key under which the value will be placed within the dispatcher.
     *
     * @var string
     */
    protected $Key;

    /**
     * The string that will be placed within the dispatcher.
     *
     * @var string
     */
    protected $Value;
 
    /**
     * The constructor is where we initialize our node. This will include supplying
     * any data that our node needs to execute correctly.
     * 
     * In this example we are supplying the Key, which is the name of the variable that
     * we will set in the dispathcer, and the Value, which is  the string that will
     * be stored in the dispatcher.
     */
    public function __construct(array $Input = []) {
 
        if (!isset($Input['Key'])) {
            $Input['Key'] = 'String';
        }
 
        if (!isset($Input['Value'])) {
            $Input['Value'] = '';
        }
 
        $this->Key = $Input['Key'];
 
        if (is_string($Input['Value'])) {
            $this->Value = $Input['Value'];
 
        } else if (is_object($Input['Value']) && method_exists($Input['Value'], '__toString')) {
            $this->Value = (string) $Input['Value'];
 
        } else {
            $this->Value = '';
        }
	}
 
    /**
     * When the node is executed, this will place the value into the dispatcher
     * under the supplied key name.
     */
    public  function Execute(DispatchInterface &$Dispatch) {
        $Dispatch->Set($this->Key, $this->Value);
    }
}