Helpers not passed correct this value within each block

[brianDoherty]

When trying to pass a helper function an argument inside of an each loop, I get the string this passed as the argument to the helper, rather than the current value of the each loop.

$engine->addHelper('foo', function($template, $context, $arg){
  return new \Handlebars\SafeString( '<strong>' . $arg. '</strong>' );
}); 

echo $engine->render(
  'Planets:<br />{{#each planets}}<h6>{{foo this}}</h6>{{/each}}',
  array(
    'planets' => array(
      'Mercury',
      'Venus',
      'Earth',
      'Mar'
    )   
  )   
);

Outputs:

Planets:<br /><h6><strong>this</strong></h6><h6><strong>this</strong></h6><h6><strong>this</strong></h6><h6><strong>this</strong></h6>

Whereas if I don't call a helper inside of the each loop, I get the correct value:

echo $engine->render(
  'Planets:<br />{{#each planets}}<h6>{{this}}</h6>{{/each}}',
  array(
    'planets' => array(
      'Mercury',
      'Venus',
      'Earth',
      'Mar'
    )   
  )   
);

Outputs:

Planets:<br /><h6>Mercury</h6><h6>Venus</h6><h6>Earth</h6><h6>Mar</h6>

I'm attempting to use the same Handlebar templates server side and client side, and this is preventing me from doing that.

[JustBlackBird]

Your helper is wrong. You need to get value from the context instead of directly use $arg argument.

The code of the helper should looks like the following:

$engine->addHelper('foo', function($template, $context, $arg){
  $value = $context->get($arg);
  return new \Handlebars\SafeString( '<strong>' . $value . '</strong>' );
}); 

[everplays]

Just like @JustBlackBird explained, handlebars.php doesn't parse arguments for you, you need to do it yourself. But there's a helper for it that you can use \Handlebars\Template::parseArguments. For more info please referrer to https://github.com/XaminProject/handlebars.php/pull/37 or checkout testArgumentParser & argumentParserProvider methods in HandlebarsTest.php file.