note 74492 added to function.create-function

In the process of migrating a PHP4 codebase to PHP5, I ran into a peculiar problem. In the library, every class was derived from a generic class called 'class_container'. 'class_container' contained an array called runtime_functions and a method called class_function that was as follows: function class_function($name,$params,$code) { $this->runtime_functions[$name] = create_function($params,$code); } In a subclass of class_container, there was a function that utilized class_function() to store some custom lambda functions that were self-referential: function myfunc($name,$code) { $this->class_function($name,'$theobj','$this=&$theobj;'.$code); } In PHP4, this worked just fine. The idea was to write blocks of code at the subclass level, such as "echo $this->id;", then simply $MYOBJ->myfunc("go","echo $this->id;"); and later call it like $MYOBJ->runtime_functions["go"](); It essentially worked exactly like binding anonymous functions to objects in Javascript. Note how the "$this" keyword had to be manually redefined for the $code block to work. In PHP5, however, you can't redeclare $this without getting a fatal error, so the code had to be updated to: function myfunc($name,$code) { $this->class_function($name,'$this',$code); } Apparently create_function() allows you to set $this via a function argument, allowing you to bind anonymous functions to instantiated objects. Thought it might be useful to somebody. ---- Server IP: 69.147.83.197 Probable Submitter: 75.9.130.114 ---- Manual Page -- http://www.php.net/manual/en/function.create-function.php Edit -- https://master.php.net/note/edit/74492 Del: integrated -- https://master.php.net/note/delete/74492/integrated Del: useless -- https://master.php.net/note/delete/74492/useless Del: bad code -- https://master.php.net/note/delete/74492/bad+code Del: spam -- https://master.php.net/note/delete/74492/spam Del: non-english -- https://master.php.net/note/delete/74492/non-english Del: in docs -- https://master.php.net/note/delete/74492/in+docs Del: other reasons-- https://master.php.net/note/delete/74492 Reject -- https://master.php.net/note/reject/74492 Search -- https://master.php.net/manage/user-notes.php