I can't figure how to work Output Buffer

[Bisa]

I'm working on a basic structure for websites containing user management and a template engine.

I've run into troubles with the template engine when I try to allow for including scripted pages.

 

This function is supposed to include and buffer the scripted page:

	function parse_file($file) {
		ob_start();
		include($file);
		$buffer = ob_get_clean();

		return $buffer;
	}

 

In my template class I check to see if the data entered is a file or not, if it is then I run these lines to replace place holder-tags with the output buffer of the file included:

			foreach ($tags as $tag => $data) {
				if (file_exists($data)){
					$data = $this->parse_file($data);
				}

				$this->page = preg_replace('/{' . $tag . '}|<!-- '.$tag.' -->/', $data, $this->page);
			}

 

now here is the hitch, it seems the preg_replace is only replacing one of several identical place holder-tags and I am puzzled as of why this happens, could it be the buffer or what?

[simshaun]

If it's replacing at least one placeholder tag, then that means parse_file() is working.  (You are using OB the right way)

 

So, are you saying your "template" contains multiple {test} tags (just used test as an example), and only one of them is being replaced?  If so, I think the error lies somewhere else in your code, because the loop you provided should work just fine.  The only thing I would do to it is wrap the occurences of $tag with preg_quote in your preg_replace call.

[Bisa]

I see.

 

And yes, I use {PAGE_TITLE} two times for example. One time in the header.html that I am including (the html gets printed out just fine) and a second time in the body. The only time I actually get the title printed is in the body where it's preg_replaced based on a tag associative array " Title" => "My Page Title"

 

what seems to be the issue here is that whenever Ive included a file such as my header.html the preg_replace won't replace my {PAGE_TITLE} which should be located in the buffer output string - instead it just skips it and I'm left with the place holder being echoed rather then my desired title.

[simshaun]

Hmm wait.

 

What's the structure of $tags? (do a print_r on it and paste)

 

I would assume it would be like you said, array('title' => 'My Page Title', 'meta_keywords' => 'foo, bar').

If so, why are you trying to load the value of each element as if it were a file.  I was mistaken above.. now I do think your logic is flawed in the loop.

 

You should:

1. Parse (load) the file before the loop (i.e. $this->page = $this->parse_file('header.html') ).

2. Loop through $tags. It should contain the preg_replace call you already use, but not the if file exists control structure.

[Bisa]

$tags print_r results in this:

Array ( [PAGE_TITLE] => Index [PAGE_HEAD] => ./templates/page_head.html [PAGE_FOOT] => ./templates/page_foot.html ) 1

 

and by that you might figure that I cannot simply parse the file before the loop as I would need to parse both head and foot thus making the buffer consist of only head and foot, or am I thinking wrong there?

[Bisa]

Actually, yes, the loop logic was kinda flawed, what I realized due to your input was the following:

 

Since the {PAGE_TITLE} had already been handled in the first circulation it couldn't be replaced magically in some way once the files had been included which also contained {PAGE_TITLE}. What I did to solve this was, as u suggested, simply to include the pages first and then loop through the tags that had only replacements in it for them

 

Thnx

[simshaun]

Ok I see what you are trying to do.  Now we're back to square 1.  I'm fairly certain it's a problem somewhere else in your code.

 

<?php
function parse_file($file) {
ob_start();
include($file);
$buffer = ob_get_clean();
return $buffer;
}

$tags = array('header' => 'header.php', 'footer' => 'footer.php', 'title' => 'Index');

$template = '{header}

<h1><!-- title --></h1>
<p>Hello world</p>

{footer}';

echo '<pre>';
foreach ($tags AS $tag => $data) {
if (is_file($data)) {
	$data = parse_file($data);
}

$template = preg_replace('/{'. preg_quote($tag,'/') .'}|<!-- '. preg_quote($tag,'/') .' -->/', $data, $template);

echo "\n\nTag: $tag";
echo "\nData: $data";
}
echo '</pre>';

echo '<hr>';
echo $template;

That is basically what you are doing. header.php contains Foo and footer.php contains Bar. Works just fine.

 

 

Edit: Glad you got it worked out.