How to create a function with the same context as require in PHP?

This question is due to an error when I try to use this on a file. I have a file with a class for the page:

class Page {
   function whatHappen()
   {
      echo "this may work";
   }  
   function helloWorld()
   {
       echo "This is my page!";
       require( "usethis.php" );      // --> this works
       similar_require( "usethis.php" );    // ---> with this I get an error
   }
   function write()
   {
       $this->helloWorld();
   }
}

And a function that similar to require:

function similar_require( $filepath )
{
   require( $filepath );
}

In usethis.php file I have this:

<?php开发者_C百科
   $this->whatHappen();
?>

How to do work similar_require and require like the same function?

In usethis.php you are trying to access $this, which is not declared in scope of similar_require function.
Read about visibility: http://www.php.net/manual/en/language.variables.scope.php

All this code looks very dirty: don't use 'require' or 'include' in methods or functions - it's like using globals (and globals are very bad thing).

Maybe this will work:

function similar_require( $filepath, $this )
{
   require( $filepath );
}

and

similar_require( "usethis.php", $this );