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I do not understand calling sale function of new product

Posted on 2014-03-25
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Medium Priority
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Last Modified: 2014-03-30
<?php
require_once( "closures.php" );

$logger = create_function( '$product', 
                           'print "    logging ({$product->name})\n";' );

$processor = new ProcessSale();
$processor->registerCallback( $logger );

$processor->sale( new Product( "shoes", 6 ) );
print "\n";
$processor->sale( new Product( "coffee", 6 ) );
?>

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closures.php
<?php

class Product {
    public $name;
    public $price;
    function __construct( $name, $price ) {
        $this->name = $name;
        $this->price = $price;
    }
}

class ProcessSale {
    private $callbacks;

    function registerCallback( $callback ) {
        if ( ! is_callable( $callback ) ) {
            throw new Exception( "callback not callable" );
        }
        $this->callbacks[] = $callback;
    }

    function sale( $product ) {
        print "{$product->name}: processing \n";
        foreach ( $this->callbacks as $callback ) {
            call_user_func( $callback, $product );
        }
    }
}
?>

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I do not understand calling sale function of new product

$processor->sale( new Product( "shoes", 6 ) );
0
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Question by:rgb192
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6 Comments
 
LVL 35

Expert Comment

by:gr8gonzo
ID: 39955054
What specifically do you not understand about it?

To be clear, the sale function does not belong to the new product. The sale function belongs to the $processor object, and the code is creating a new product object and passing that new product as a parameter to the $processor's sale function.
0
 

Author Comment

by:rgb192
ID: 39956570
Calling 2 methods at the same time
0
 

Author Comment

by:rgb192
ID: 39962398
I do not understand calling two classes at the same time.

Sale method of new product
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What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 
LVL 35

Accepted Solution

by:
gr8gonzo earned 2000 total points
ID: 39963127
This code:
$processor->sale( new Product( "shoes", 6 ) );

...could be rewritten as two lines:

$temporary_variable = new Product( "shoes", 6 );
$processor->sale( $temporary_variable );

The only difference is that the "new Product" part is created in memory and is passed immediately to the sale function and there is no $temporary_variable or other variable to reference it outside of the function.
0
 

Author Comment

by:rgb192
ID: 39964987
okay same output but easier to understand

//$processor->sale( new Product( "shoes", 6 ) );
$temporary_variable=new Product("shoes", 6);
$processor->sale($temporary_variable);



Next part of sale function I do not understand is the foreach
this run was value lambda_8, last run was lambda_8
Only one run in the foreach


what is lambda and why always run once
0
 

Author Closing Comment

by:rgb192
ID: 39965428
Yes you answered the question about calling the method.
Thank you.

Second question about this method is:
http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/Q_28400934.html
0

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What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

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