[RESOLVED] Object Iteration

r_honey

I am trying to make by classes Iterable by implementing Iterator Aggregate & Iterator interfaces. But whenever my class implemets any of these, I get a Class Not Found error for that class.

So, how can I make my class Iterable???

laserlight

Why not provide the smallest and simplest code that demonstrates the error?

r_honey

class Collection implements IteratorAggregate
{
    private $item = array();

public function getIterator()
{
    return new MyIterator($this->item);
}

.... More Code
}

class Another
{
    function __construct()
    {
        $col = new Collection();
//Gives Class 'Coolection' not found
    }

}

laserlight

I cannot duplicate the error using your code snippet on PHP 5.2.3. What version of PHP did you use, and what exactly did you try? Take out the ".... More Code" portion as it makes your code no longer the "smallest and simplest".

r_honey

I installed PHP using Xammp which installed PHP 5.2.2 + 4.4.7.
Do I have to do something special to parse my code with PHP 5.2.2???

Also, on the SPL section of php.net, there is something about prepend files, & prepending autoload.inc. I checked out my installation. There's not a autoload.inc file.
Does that makes a difference???

laserlight

I installed PHP using Xammp which installed PHP 5.2.2 + 4.4.7.
Do I have to do something special to parse my code with PHP 5.2.2???

I do not think so, since I actually tested with PHP 5.2.2 before upgrading to PHP 5.2.3 just a few minutes before I posted 🙂

r_honey

I checked out, I have PHP5 running..
So, what now???

laserlight

Not sure what is the problem. Just to confirm: are you sure that it is not a typo? I note that you wrote the error message as "Gives Class 'Coolection' not found" instead of "Gives Class 'Collection' not found".

r_honey

I also noted that in my post.
But in the code... nope

I use Macromedia DreamWeaver to code. One particular thing of interest I have noted is that, DreamWeaver color encodes program structs, but it is not color encoding the "implements" clause.
Don't ask me to check for a typo again. I have done that carefully (Come on, it's a single word).

Does that provides some hint???

I again repeat, on the SPL section of php.net, there is something about prepend files, & prepending autoload.inc. I checked out my installation. There's not a autoload.inc file or for that matter, any *iterator.inc file.
Does that makes a difference???

laserlight

hmm...
As a test try this:

<?php
class Collection implements IteratorAggregate
{
    private $item = array('foo', 'bar', 'baz');

public function getIterator()
{
    return new ArrayIterator($this->item);
}
}

class Another
{
    function __construct()
    {
        $col = new Collection();

    for ($iter = $col->getIterator(); $iter->valid(); $iter->next())
    {
        echo $iter->current() . "<br />\n";
    }
}
}

$another = new Another();
?>

My output is as expected:

foo
bar
baz

What do you get?

r_honey

I am having a love-hate relationship with PHP:mad:

My code organization was as follows:

class First
{
   someMethod()
   {
      calls a method in class second, say method();
   }
}

class Collection //implements IteratorAggregate
{
   //I wanted this to be iterable.
}

class Second
{
   method()
   {
      //Collection instance is being instantized here.
   }
}

The above organization worked fine. Notice Coolection is not iterable yet.
When I uncomment //implements...,
now the parser starts emitting out Class 'Collection' not found.

If you say, that the definition of Collection has not yet been parsed, then why is it working when the class is not Iterable???

Shifting Collection to the top of the file, & then uncommenting the //implements..
clause finally made evrything work.

I mean this is real madness. It almost drived me nuts..

Is this a bug with PHP???

laserlight

I still cannot duplicate the error. If it is really the case, then I would suspect that it is a bug. Please post your actual code so that we can read, run it and see. A comment like "calls a method in class second, say method();" is not good enough, since it could be due to some other error that you have inadvertently made.

r_honey

<?php
class MySqlDB
{
	private $con;
	public function executeQuery($query)
	{
		$this->con = mysqli_init();
		$success = $this->con->real_connect("localhost",
							"root",
							"passwd",
							"Bugs");
		$query = trim($query);
		$resultSet = $this->con->query($query);
		$resultTable = new DataTable($resultSet);
		$resultSet->free_result();
	}

}

$var = new MySqlDB();
$resultTable = $var->executeQuery("SELECT * FROM temp WHERE f1 LIKE 'PHP';");
var_dump($resultTable);

class ColumnCollection implements IteratorAggregate
{
	public $count = 0;
	private $item = array();

//Build & returns a DataColumnCollection from the parameters passed.
public function __construct($fieldSet = array())
{
}

// Required definition of interface IteratorAggregate
public function getIterator()
{
    return new ArrayIterator($this->item);
}
}

class DataTable
{
	public function __construct($resultSet)
	{
		$fieldSet = $resultSet->fetch_fields();
		$this->columns = new ColumnCollection($fieldSet);
	}
}
?>

I had almost submitted it as a bug at php.net, when I cam across the following bogus-declared bug, & decided not to submit it!!!
http://bugs.php.net/bug.php?id=37753

laserlight

Ah, I understand now. I would say that the rule to follow is to define all the classes that will be used before you write the code that instantiates the objects of those classes. The PHP manual says concerning the basics of classes:

Classes should be defined before instantiation (and in some cases this is a requirement).

r_honey

I also went through it on php.net. If the error would have shown even when the class was not iterable, it would have been a snap to catch it.

Its just so difficult to do that simply on implementing an interface (in my case uncommenting it🙂 ).

What's more, the Object Iteration sub-section does not mention anything about this. And moreover, when you serach for 'Interface' or 'Iterator' on php.net, all results shown are Broken links!!!

Anyways, I have added the note there...