Question

I’m writing a mail class that pulls content stored in a database and loads it into a template before sending it as a HTML e-mail. However, because each e-mail contains PHP variables and dynamic content, I’ve decided to use delimiters. So instead of the content looking like:

Hello $username, welcome to the site.

It’ll look like:

Hello {{username}}, welcome to the site.

So far I’m using these methods:

function load($name,$content)
{
    // preps the template for HTML
}

function content($template_id)
{
    $template = $this->db->get_where('email_templates',array('id'=>$template_id));
    return $template->content;
}

function new_email($email,$name,$user_type)
{
    $msg = $this->load($name,$this->content(1));
    $this->send($email,'Thanks for your application',$msg,1);
}

The trouble I’m having is how to convert a {{variable}} into a $variable so that it will parse – I don’t want it to just be loaded as $username in the e-mail template. Is it just a case of using regular expressions and escaping the string so that it’ll parse? Something like:

$content = str_replace("{{","'.$",$template->content);
$content = str_replace("}}",".'",$template->content);

Or is this flawed? Does anybody know what’s the best thing to do?

Answer 1

I would not create my own templating system, because there are existing ones out there.

The most popular is probably Smarty, but there is an another one which has the same format as you created, that is mustache.

Update:

The problem with your code is that you’re replacing the {{ to a .$ and store that in $content variable, then replacing }} to . and overwrite this replaced $content variable.

A possible working solution could be:

if (preg_match_all("/{{(.*?)}}/", $template, $m)) {
  foreach ($m[1] as $i => $varname) {
    $template = str_replace($m[0][$i], sprintf('$%s', $varname), $template);
  }
}

But then you would also need to eval your code somehow.