Bug #52396 [Bgs]: Acessing a class within a static class

Edit report at http://bugs.php.net/bug.php?id=52396&edit=1 ID: 52396 User updated by: mark at rwrightson dot f9 dot co dot uk Reported by: mark at rwrightson dot f9 dot co dot uk Summary: Acessing a class within a static class Status: Bogus Type: Bug Package: Class/Object related Operating System: Windows 7 PHP Version: 5.3.2 New Comment: Apologies for posting long code here. The code aharvey posted doesn't demonstrate the problem. I have added a small amount of extra code to his code to demonstrate the exact issue. http://www.voltnet.co.uk/phperror/52396.txt I should probably mention that this example doesn't work on php 5.2.9 but it does work on php v5.3.2 The code should output: "ClassThatPrintsItsName hello" If line 41 is commented out and replaced with line 42 the following error will appear: Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in C:\htdocs\error.php on line 41. Looking at the two lines below, the problem that is occurring is when trying to statically access a static variable within a class that has already been statically accessed. $c::$bar::$another->hello(); //this line won't work $c::$bar->getAnother()->hello(); //this line will work The line (line 41) that won't work can be rewritten as: $a = $c::$bar; $a::$another->hello(); and this will make it work I hope this better demonstrates the issue Previous Comments: ------------------------------------------------------------------------ [2010-07-23 12:20:38] aharvey@php.net Closing, because I can't reproduce this. Even if I uncomment the right line in your example, that is: self::$bar->test->hello(); It appears to do what it's supposed to. I've put a much simpler version of what I think your problem is up at http://codepad.viper-7.com/l2GN2F and that also works normally. Also, please note that we'd really prefer reproduce code that's no more than about 20 lines -- I had a fair job trying to follow what was going on in your code. :) ------------------------------------------------------------------------ [2010-07-22 00:42:35] mark at rwrightson dot f9 dot co dot uk Description: ------------ It is currently not possible to access a class that is instantiated within another class that is instantiated within a static object variable. Using the example below I would expect this line of code to function correctly: (where self is Foo) self::$bar->test->hello(); however this isn't the case. A getter must be created in the bar() class to get the test class object variable. I.e. getTest(). The above line can then be re-written as : self::$bar->getTest()->hello(); this works correctly. In finding this solution I also tried the same concept in another OO language (Java). I copied the code as per below and altered the syntax. the line above became: bar.test.hello(); which worked ok. For this reason, as the operation discussed here is a standard OO concept, it could be classed as a bug within PHP. The attached test script demonstrates the getTest() workaround. commented out above this line are numerous error messages that I encountered when trying to access the test class. Many Thanks Test script: --------------- <?php echo "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"> <html xmlns=\"http://www.w3.org/1999/xhtml\" lang=\"en\" xml:lang=\"en\"> <head> <title>XHTML-document </title> </head> <body>"; new foo(); echo"</body> </html>"; class foo { public static $bar; public static $foo2; public function __construct() { echo"<code>construct foo</code>"; echo"<p>create static instance of bar</p>"; self::$bar = new bar(); echo"<p>call hello() in bar class</p>"; self::$bar->hello(); echo"<p>call hello() in test class from Foo class through bar class</p>"; //N.B. The following methods failed. However there is one solution... //self::$bar->$test->hello(); //Notice: Undefined variable: test in ... on line... //Fatal error: Cannot access empty property in ... on line... //self::$bar->test->hello(); //Notice: Undefined property: bar::$test in ... on... //Fatal error: Call to a member function hello() on a non-object in ... on... //self::$bar::$test->hello(); //Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in ... on... //self::$bar::test->hello(); //Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in ... on... //self::$bar->self::$test->hello(); //Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in ... on... //self::$bar::self::$test->hello(); //Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM in ... on... self::$bar->getTest()->hello(); echo"<p>create static instance of foo2</p>"; self::$foo2 = new foo2(); } } class bar { //N.B. the class Test() can be instantiated as either a static or a normal variable //public static $test; public $test; public function __construct(){ echo "<code>construct bar</code>"; echo"<p>create static instance of test class in bar class </p>"; //self::$test = new test(); $this->test = new test(); } public function hello(){ echo"<code>class:foo function:hello()</code>"; } public function getTest(){ //echo"getanother"; //return self::$test; return $this->test; } } class test{ public function __construct(){ echo "<code>construct test</code>"; } public function hello(){ echo "<code>class:test function:hello()</code>"; } } class foo2 { public function __construct() { echo"<code>construct foo2</code>"; echo"<p>call hello() in foo2 class</p>"; foo::$bar->hello(); } public function hello(){ echo"class:foo2 function:hello"; } } ?> Expected result: ---------------- construct foo create static instance of bar construct bar create static instance of test class in bar class construct test call hello() in bar class class:foo function:hello() call hello() in test class from Foo class through bar class class:test function:hello() create static instance of foo2 construct foo2 call hello() in foo2 class class:foo function:hello() Actual result: -------------- same as above. the code demonstrates a work around to the problem. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52396&edit=1