difficult __call function. need help!!

[Paul_help_]

Hi friends.

I am currently reading a book and there is some confusion in regards to the built in __call() method.

The code i am working on is below:

< !DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd” >
< html xmlns=”http://www.w3.org/1999/xhtml” xml:lang=”en” lang=”en” >
< head >
< title > Creating a Wrapper Class with call() < /title >
< link rel=”stylesheet” type=”text/css” href=”common.css” / >
< /head >
< body >
< h1 > Creating a Wrapper Class with call() < /h1 >
< ?php
class CleverString {
private $_theString = “”;

private static $_allowedFunctions = array( “strlen”, “strtoupper”,
“strpos” );

public function setString( $stringVal ) {
$this- > theString = $stringVal;
}

public function getString() {
return $this- > theString;
}

public function __call( $methodName, $arguments ) {
if ( in_array( $methodName, CleverString::$_allowedFunctions ) ) {
array_unshift( $arguments, $this- > theString );
return call_user_func_array( $methodName, $arguments );
} else {
die ( “ < p > Method ‘CleverString::$methodName’ doesn’t exist < /p > ” );
}
}
}

$myString = new CleverString;
$myString- > setString( “Hello!” );
echo “ < p > The string is: “ . $myString- > getString() . “ < /p > ”;
echo “ < p > The length of the string is: “ . $myString- > strlen() . “ < /p > ”;

The piece of code in particular i am having trouble understanding is:

public function __call( $methodName, $arguments )

To be even more specific I do not understand what the $arguments parameter is suppose to represent.
In the book I am reading, it explained that the $arguments property is any arguments passed to the non existent
method as an array.

I am confused.

Is the $arguments property an array??? or is it the parameters of $methodName???

because surely it can't be both.

Paul.

[bradgrafelman]

Paul help!;11032979 wrote:

Is the $arguments property an array??? or is it the parameters of $methodName???

because surely it can't be both.

Don't be so sure! 🙂

Not sure exactly what you mean by "parameters of $methodName", but it sounds like the answer is yes to both questions. See this page in the PHP manual for more info about the __call() magic method.

For an example, this code:

<?php
class Foo
{
    public function __call( $methodName, $arguments )
        {
        echo "You attempted to call the nonexistent function $methodName!\n";
        echo "\tArgs: " . implode( ', ', $arguments ) . "\n";
        }
}

$test = new Foo;
$test->bar( 'Hello', 'World', '!' );

would produce this output:

You attempted to call the nonexistent function bar!
        Args: Hello, World, !

[Paul_help_]

Ok. So the arguement in my example (above) is the word 'Hello!' ???

$myString- > setString( &#8220;Hello!&#8221; );

[bradgrafelman]

In your example above, the __call() magic method is only invoked for the last line where you attempt to call $myString->strlen(). (And in that case, $arguments would be an empty array since you don't pass in any arguments.)

EDIT: More complete example to show when __call() would be used:

<?php

class Foo
{
    public function baz()
        {
        echo "Nothing to see here...\n\n";
        }

private function foobar()
    {
    echo "You just called a private function!\n\n";
    }

public function __call( $methodName, $arguments )
    {
    echo "You attempted to call the nonexistent/inaccessible method $methodName!\n";
    echo "\tArgs: " . implode( ', ', $arguments ) . "\n\n";
    }
}

$test = new Foo;
$test->baz( 'Hello', 'World', '!' );
$test->foobar( 'Hello', 'World', '!' );
$test->bar( 'Hello', 'World', '!' );

resulting output:

Nothing to see here...

You attempted to call the nonexistent/inaccessible method foobar!
        Args: Hello, World, !

You attempted to call the nonexistent/inaccessible method bar!
        Args: Hello, World, !