how to access to event object propereties I want to access for particular information which is contained in event object.

public function init()
{
    parent::init();

    craft()-&gt;on('entries.saveEntry', function(Event $event) 
    {

        var_dump($event-&gt;params['entry']);
    });
} 


it dumps info (brining a needed part)

     ......
["_preppedContent":"Craft\BaseElementModel":private]=&gt;
  array(1) {
    ["tweet"]=&gt;
    array(23) {
      ["created_at"]=&gt;
      string(30) "Thu Nov 13 09:15:40 +0000 2014"
      ["id"]=&gt;
      float(5.3282410346476E+17)
      ["id_str"]=&gt;
      string(18) "532824103464763392"
      ["text"]=&gt;
      string(115) "'The innovation insight you didn't get from Forbes' great blog by @LydiaRagoonanan @nesta_uk http://t.co/PImPVvWeAv"
      ["source"]=&gt;
      string(63) "Hootsuite"
      ["truncated"]=&gt;
      bool(false)


How can I extract text, id_str information?
Thanks
I assume both text and id_str are custom fields?

$event-&gt;params['entry']


Is an EntryModel, so you should be able to do this:

$entry = $event-&gt;params['entry'];
$idString = $entry-&gt;id_str;
$text = $entry-&gt;text;