How to separate layout and content best? - php

Question

I want to use the same website layout (header, footer, sidebar, ...) for all webpages. Only the content changes. For the sake of reusability and readability I don't want to include the entire layout stuff each time. A class called WebsiteFormatter is supposed to help be out
class WebsiteFormatter {
private $title;
private $body;
function addWebsiteTitle($title) {
$this->title = $title;
}
function addWebsiteBody($body) {
$this->body = $body;
}
function getWebsite() {
// load basic framework from file
$html = file_get_contents("../sites/hui.php");
$vars = array(
'{$title}' => $this->title,
'{$body}' => $this->body);
echo strtr($html, $vars);
}
}
A random page could look like as follows:
$layout = new WebsiteFormatter();
$layout->addWebsiteTitle("Foo Barr");
$body = "<h1> The Holy Grail </h1><p>Once upon a time ...</p>";
$layout->addWebsiteBody($body);
echo $layout->getWebsite();
In getWebsite() the basic layout is loaded. Then placeholders are replaced by the actual content. This works fine, but actually I want to evaluate some PHP code, which is embedded in layout, as well. For example some session data should be displayed in the header and I do not want to introduce placeholders for every tiny attribute.
Is there a good way to evaluate such code or is my approach a complete fail?

Answer 1

You can use include() to execute the underlaying php script. If you don't want the Output right away, you can redirect the output to a variable and append it to your html-string.
For example:
ob_start();
$vars = array(
'{$title}' => $this->title,
'{$body}' => $this->body);
include "../sites/hui.php"; //can reference $vars as usual
$buffer= ob_get_contents();
ob_end_clean();
$html .= $buffer;
On a quite similiar Project we did it like this:
abstract class Page
...
private $html;
public abstract function renderPage();
...
public function parseTemplate($template, $data = array()) {
ob_start(); //Start output buffering
include("templates/" . $template . ".php"); //generate output
$html = ob_get_clean(); //catch output buffer
return $html; //return rendered html
}
}
(ob_get_clean is equal to ob_get_contents followed by ob_end_clean)
where a page extends the Page-Class
class Dashboard extends Page{
function renderPage(){
...generate data-array
$this->html .= $this->parseTemplate("dashboard", $data);
}
}
and templates/Dashboard.php just contains dumb usage of the $data Array along with html-markup.