OOP problem, I think

SOL-ion

Hi all,

I have just started a new project. I have decided to make it object orientated and straight away I have an error which I don't understand. Does anyone have any ideas?

Error message is:
Parse error: parse error in /usr/HTTPServer/htdocs/en_US/html_output.obj on line 12

The object being called within the object is:

<?
class obj {
	function inc_header ( $site_title, $page_title ) {       

	}
	function inc_footer () {
	} 
}  // class obj
?>

The object is called here:

<?
include ("obj.obj");

class HTML_Output {
	// error is thrown here
                var $w3 = new obj ();
	function display_stage1 () { 
		//$obj -> inc_header ("site title", "page title");?>
		<h1>*** Express</h1>
	<?php }  // display_stage1

}  // class HTML_Output
?>

laserlight

I'm not sure why it is a parse error, but it could be that you shouldnt be using
var $w3 = new obj();

instead, initialize $w3 using a constructor.

SOL-ion

Thanks for that. I have changed the code and it has changed the error message now 🙂

The error message is now:
Fatal error: Call to a member function on a non-object in /usr/HTTPServer/htdocs/en_US/html_output.obj on line 18

My HTML_Output object now looks a bit like this.

<?
class HTML_Output {
        var $w3;
        function HTML_Output () {
                $w3 = new obj ();        

        }  // constructor

    function display_stage1 () { 
// error occurs here		
$w3 -> inc_header ("site title", "page title");?>
		<h1>*** Express</h1>
	<?php }  // display_stage1
}  // class HTML_Output
?>

laserlight

you probably have to use a
global $w3;

actually, if the $w3 object is used like a function library, it might be better to place it outside the class definition and declare global as needed

SOL-ion

Is that still maintaining a OO design?

laserlight

yes, it is.

the objects will be related in a many to one relationship then.
each instance of the HTML_Output class will use the single instance of the obj class.

SOL-ion

Thanks very much, I will try that tomorrow. I am sure it will work.

ahundiak

Actually, you might want to spend some time reading the chapter on objects in the manual. There are also several articles on phpbuilder.

Use $this when accessing member variables.

class HTML_Output
{
function HTML_Output()
{
$this->w3 =& new obj();
}
}