page_obj class

russellhanby

<?php
class page_obj
{
private $header;
private $footer;
function __construct($title = "",$links = "")
{
ob_start(array(&$this,'output_callback'));
ob_clean();
$this->header = "<HTML>\n" .
"<HEAD>\n";
if(!$title=='')
$this->header .= "<TITLE>$title</TITLE>\n";

	if(is_array($links))
	{
		foreach($links as $value)
		{
			if((int)eregi('(css)',$value) > 0) $this->makeLinks('css',$value);
			if((int)eregi('(js)',$value) > 0) $this->makeLinks('js',$value);
		}
	}
	elseif(is_string($links) and !$links=='')
	{
		if((int)eregi('(css)',$links) > 0) $this->makeLinks('css',$links);
		if((int)eregi('(js)',$links) > 0) $this->makeLinks('js',$links);
	}

	$this->_header .= "</HEAD>\n" .
								  "<BODY>\n";

	$this->_footer = "</BODY>\n" .
							  "</HTML>";
	echo $this->_header;
}

function makeLinks($type = '',$href = '')
{
	global $_header;
	if($type=='' or $href=='') return;
	elseif($type=='css')
		$this->_header .= "<LINK REL=\"stylesheet\" TYPE=\"text/css\" HREF=\"$href\"/>\n";
	elseif($type=='js')
		$this->_header .= "<LINK TYPE=\"text/javascript\" HREF=\"$href\"/>\n";
	else return;
}

function output_callback($buffer)
{
	return $buffer . $this->_footer;
}

}
?>

This class I wrote seems to work rather nicely, so I thought I'd post it for all to comment on. Let me know, ay?

Shrike

The constructor of a class should be used to initialise the member variables. I suggest that you create a makeHeader() method and move the relevant code in there. That would also mean you can remove the ugly output buffering which is wholly unneccessary.

I would also add getter and perhaps setter methods for setHeader and setLinks, thereby removing the if/else logic in the constructor. Breaking things down in this way will make the class more flexible, and extensible.

Another minor point; in the function makeLinks() the line 'global $header' is not needed, in fact $header is a completely different variable to $this->_header.

russellhanby

U were right about the global thing. It seemed like I'd needed it in the past, but I guess not. I'm still getting used to php. The code was meant to make sure an HTML header and footer were attached to each page (hense the ob_start()).

russellhanby

<?php
interface ipage
{
public function setHeader($header);
public function setFooter($footer);
public function getHeader();
public function getFooter();
}
class page_obj implements ipage
{
private $header;
private $footer;
private $linkHREFs;
private $title;
function __construct($title='',$linkHREFs='',$ob = false,$header='',$footer='')
{
$this->title = $title;
$this->linkHREFs = $linkHREFs;
$this->header = ($header=='') ? $this->makeHeader($this->title,$this->linkHREFs) : $header;
$this->footer = ($footer=='') ? $this->makeFooter() : $footer;
if($ob==true)
{
ob_start(array(&$this,'output_callback'));
ob_clean();

	}
}

public function setHeader($header)
{
	$this->_header = $header;
}

public function setFooter($footer)
{
	$this->_footer = $footer;
}

public function setLinkHREFs($hrefs)
{
	$this->_linkHREFs = $hrefs;
}

public function setTitle($title)
{
	$this->_title = $title;
}

private function makeHeader($title,$linkHREFs)
{
	$header = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/html4/strict.dtd\">\n" .
					  "<HTML>\n" .
					  "<HEAD>\n";
	if(!$title=='')
		$header .= "<TITLE>$title</TITLE>\n";

	if(is_array($linkHREFs))
	{
		foreach($linkHREFs as $href)
		{
			$header .= $this->makeLink($href);
		}
	}
	elseif(is_string($linkHREFs) and $linkHREFs!='')
	{
		$header .= $this->makeLink($linkHREFs);
	}

	$header .= "</HEAD>\n" .
					   "<BODY>\n";
	return $header;
}

private function makeFooter()
{
	$footer = "\n</BODY>\n" .
					"</HTML>";
	return $footer;
}

private function makeLink($href)
{
	if(eregi('(css)',$href) > 0)
		return "<LINK TYPE=\"text/css\" REL=\"stylesheet\" HREF=\"$href\" />\n";
	elseif(eregi('(js)',$href) > 0)
		return "<LINK TYPE=\"text/javascript\" HREF=\"$href\" />\n";
	else return;
}

public function getHeader()
{
	return $this->_header;
}

public function getFooter()
{
	return $this->_footer;
}

public function getTitle()
{
	return $this->_title;
}

public function getLinkHREFs()
{
	return $this->_linkHREFs;
}

public function output_callback($buffer)
{
	return $buffer . $this->_footer;
}

}
?>

Okay, so now it can be my custom header or one of ur own. Is that what I should have been going for?

Shrike

If possible try to call public methods of your class with client code rather than internally. If you are using lots of if/else logic inside of the class it's a good sign that something is wrong and it's in need of refactoring. I've done a quick skeleton script based on your ideas, see what you think.

<?php

class Page 
{
	// An array of links
	private $links = array();
	// The page title
	private $title;

// Constructor
// Sets the page title
function __construct( $title = null )
{
	$this->title = $title;
}
// Adds a link to the links array
// note parameter must be an object of type Ilink
public function addLink( Ilink $link )
{
	$this->links[] = $link
}
// returns a string representing the page header
// Iterates over the links list generating links
public function getHeader()
{
	$string = <<<EOF
<html>
  <head>
    <title>$this->title</title>
    		EOF;
    		foreach( $this->links as $link )
    		{
    			$string .= $link->createLink();
    		}
    		$string .= <<<EOF
  </head>
<body>
		EOF;
		return $string;
	}
	// Returns a string representing the page footer
	public function getFooter()
	{
		$string = <<<EOF
</body>
</html>
		EOF;
		return $string;
	}

}
// Link interface, provides a common API for links
interface Ilink
{
	public function createLink();
}
// css link type, returns a <link> tag
class cssLink implements Ilink
{	
	private $url;

function __construct( $url )
{
	$this->url = $url;
}
// This method is required by classes which implement Ilink
public function createLink()
{
	return '<link rel="stylesheet" type="text/css" href="' . $this->url . '"/>';
}
}
// Javascript link type, returns a <script> tag
class javascriptLink implements Ilink
{
	private $url;

function __construct( $url )
{
	$this->url = $url;
}
// This method is required by classes which implement Ilink
public function createLink()
{
	return '<script type="text/javascript" href="' . $this->url . '"/></script>';
}
}

// Client code. This should be separate to the classes

// Make a new page, and set the title
$page = new Page( 'Test page' );
// Add some links
$page->addLink( new cssLink( 'styles.css' ));
$page->addLink( new javascriptLink( 'scripts.js' ));
// Echo the header
echo $page->getHeader();
// Page content comes next
?>
<p>This is the page content.</p>
<?php
// echo the footer
echo $page->getFooter();
?>

Note the code is untested and so probably doesn't work 😉

russellhanby

Very nice... damn you...

russellhanby

Very nice... So, when u specified ILink in the addLink argument list, does that specifiy that what's passe has to be of interface ILink? Cause that makes sense, but I didn't know you could do that in php. I feel it necessary to explain myself. I realize that the class is sloppy, but I was looking to minimize coding on each individual page, otherwise I'd type out the header and footer myself, right? Thanx for your help.

russellhanby

So I wrote this for meta tags:
<?php
require_once('interface.iLink.php');
class metaLink implements iLink
{
private $name;
private $http_equiv;
private $content;

function __constuct($name,$http_equiv,$content)
{
	$this->name = $name;
	$this->http_equiv = $http_equiv;
	$this->content = $content;
}

function createLink()
{
	$link = "<META ";
	if(!$this->name=='') $link .= "NAME=\"$this->name\" ";
	if(!$this->http_equiv=='') $link .= "HTTP-EQUIV=\"$this->http_equiv\" ";
	if(!$this->content=='') $link .= "CONTENT=\"$this->content\" ";
	$link .= "/>\n";
	return $link;
}

}
?>
Is this up to par?