Traditionally, programming templates into your applications goes as
    follows: First, you accumulate your variables within your PHP
    application, (maybe with database queries.) Then, you instantiate your
    Smarty object, assign()
    the variables and display()
     the template. So lets
    say for example we have a stock ticker on our template. We would
    collect the stock data in our application, then assign these variables
    in the template and display it. Now wouldn't it be nice if you could
    add this stock ticker to any application by merely including the
    template, and not worry about fetching the data up front?
   
You can do this by writing a custom plugin for fetching the content and assigning it to a template variable.
Example 21.7. componentized template
      function.load_ticker.php -
      drop file in
      
      $plugins directory
    
<?php
// setup our function for fetching stock data
function fetch_ticker($symbol)
{
   // put logic here that fetches $ticker_info
   // from some ticker resource
   return $ticker_info;
}
function smarty_function_load_ticker($params, $smarty)
{
   // call the function
   $ticker_info = fetch_ticker($params['symbol']);
   // assign template variable
   $smarty->assign($params['assign'], $ticker_info);
}
?>
    
          index.tpl
    
{load_ticker symbol='SMARTY' assign='ticker'}
Stock Name: {$ticker.name} Stock Price: {$ticker.price}
    
    See also
    {include_php},
    {include}
    and
    {php}.