iterator Pattern

harpua · December 28th, 2010, 05:26 PM

Hello,
I am working through the iterator pattern but when I try to loop through the array to build the table, I am getting Notice: Trying to get property of non-object errors.

I am using information from a database that I have build, same type of relationship $name, $email, $communityGear. So If I do a var_dump I am getting the following.

object(searchBySolorooerIterator)#1 (2) { ["__solorooerDetails:private"]=> array(1) { [0]=> object(solorooer)#4 (3) { ["name"]=> string(10) "Mike" ["email"]=> string(27) "[email protected]" ["communityGear"]=> array(2) { [0]=> string(7) "Doritos" [1]=> string(5) "Water" } } } ["__valid:private"]=> bool(false) }

Here is my construct function, I did things a little differently, but it should work.

Code:

	public function __construct($email) {
	
		$sql = "SELECT user.solo_ID, user.solo_Name, user.solo_Email, bbq.bbq_ItemName 
				FROM user 
				LEFT JOIN bbq
				ON user.solo_ID = roo_bbq_beerbq.bbq_SoloID 
				WHERE user.solo_Email = ?";
				
		$stmt = $conn->prepare($sql);
		$stmt->bind_param("s", $email);
		$stmt->execute();
		
		$solorooerID = 0;
		$solorooer = NULL;
		
		$stmt->bind_result($solo_ID, $solo_Name, $solo_Email, $bbq_ItemName);
		
		while ($stmt->fetch()) {
			if ($solo_ID !== $solorooerID) {
				if (!is_null($solorooer)) {
					$this->__solorooerDetails[] = $solorooer;
				}
				$solorooerID = $solo_ID;
				$solorooer = new solorooer($solo_Name, $solo_Email);
			}
			
			$solorooer->addGear($bbq_ItemName);
			
		}
		
		$this->__solorooerDetails[] = $solorooer;
		
		$stmt->free_result();
		$stmt->close();
		$conn->close();

	}

Thanks In Advanced

Mike Moore

harpua · December 29th, 2010, 05:50 PM

If I do this it works, it is like there is another layer of array deminsion being added.

Code:

foreach($rooers as $cd) {
	//$cd is an array and cannot access the "name" property
	foreach($cd as $cd2) {
		echo $cd2->name; //this works
	}
}

AaronSaray · January 5th, 2011, 10:29 PM

Hey - if you can post the rest of your class, that might be helpful. I'm quite interested to know how you implemented the methods that the iterator interface requires. That may hold a bit of clue.

Finally - a bit of description about some of the business logic may also help us get to the bottom. :) thx!

harpua · January 5th, 2011, 11:08 PM

here is the full code I have and how I am getting it to work.
I am pulling info from a database I have and formatting it to fit the book example, so ignore the fieldnames.

Code:

<?php
class CD {
	public $band = '';
	public $title = '';
	public $trackList = array();

	
	public function __construct($band, $title) {
		$this->band = $band;
		$this->title = $title;
	}

	public function addTrack($track) {
		$this->trackList[] = $track;
	}
}

class CDSearchByBandIterator implements Iterator {
	private $__CDs = array();
	private $__valid = FALSE;
	
	public function __construct($bandName) {
	
		require_once 'connection.inc.php';
		
		$sql = "SELECT user.ID, user.Name, user.Email, bbq.ItemName 
				FROM user 
				LEFT JOIN bbq 
				ON user.ID = bbq.bbqID 
				WHERE user.solo_Email = ?";
				
		$stmt = $conn->prepare($sql);
		$stmt->bind_param("s", $bandName);
		$stmt->execute();
		
		$cdID = 0;
		$cd = NULL;
		
		$stmt->bind_result($id, $band, $title, $tracktitle);
		
		while ($stmt->fetch()) {
			if ($id !== $cdID) {
				if (!is_null($cd)) {
					$this->__CDs[] = $cd;
				}
				$cdID = $id;
				$cd = new CD($band, $title);
			}
			
			$cd->addTrack($tracktitle);
			
		}
		
		$this->__CDs[] = $cd;
		
		$stmt->free_result();
		$stmt->close();
		$conn->close();

	}
	
	public function next() {
		$this->__valid = (next($this->__CDs)===FALSE) ? FALSE : TRUE;
	}
	
	public function rewind() {
		$this->__valid = (reset($this->__CDs)===FALSE) ? FALSE : TRUE;
	}
	
	public function valid() {
		return $this->__valid;
	}
	
	public function current() {
		return $this->__CDs;
	}
	
	public function key() {
		return key($this->__CDs);
	}
}


?>
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="utf-8" />
	<title>Untitled</title>
</head>
<body>
<?php

$queryItem = '[email protected]';
$cds = new CDSearchByBandIterator($queryItem);

foreach($cds as $cd) {
	foreach($cd as $cd2) {
		echo $cd2->band;
	}
}

/*
print '<h1>Found the following</h1>';
print '<table cellpadding="0">';
print '<tr><th>Band</th><th>Title</th><th>Num Tracks</th></tr>';

foreach($cds as $cd) {
	print '<tr>'.$cd->band.'<td>'.$cd->title.'</td>';
	print '<td>'.count($cd->trackList).'</td></tr>';
}

print '</table>';
*/
?>
</body>
</html>

AaronSaray · January 5th, 2011, 11:24 PM

Hi - try this code:

PHP Code:


			
public function current() {

        return current($this->__CDs);

    }

Let me know if that works for you. If it does, it may be a bug in the example code. Thanks!

harpua · January 5th, 2011, 11:40 PM

That Worked! Many Thanks, very good book by the way, very easy to understand compared to some others I have tried.