[TYPO3-team-core-v5] RFC: TagBuilder

[Bastian Waidelich]

Martin Kutschker wrote:

Hi Masi,

> Cumbersome.

I agree
	'<em>' . $this->value . '</em>';
or
	"<em>{$this->value}</em>"
is nicer than
	$tag = new Tag('em', $this->value); // or rather some 
t3lib_div::makeInstanceClassName hassle
	$tag->render();

But I'm especially talking about more complex constructions that can't 
be put in one line. Like this one (taken from the select view helper):

$out = '<select name="' . $name . '" ' . $this->renderTagAttributes() . '>';
$selectedValue = $this->getValue();
if ($this->arguments['options']) {
	if ($this->arguments['optionKey']) {
		foreach ($this->arguments['options'] as $domainObject) {
			// [...]
			$selected = '';
			if ($domainObject == $selectedValue
			    || ($this->arguments['multiple'] && in_array($domainObject, 
$selectedValue))) {
				$selected = 'selected="selected"';
			}
			// [...]
			$out .= '<option ' . $selected . ' value="' . $key . '">' . $value . 
'</option>';
		}
	} else {
		foreach ($this->arguments['options'] as $key => $value) {
			$selected = '';
			if ($key == $selectedValue) {
				$selected = 'selected="selected"';
			}
			$out .= '<option ' . $selected . ' value="' . $key . '">' . $value . 
'</option>';
		}
	}
}

I think, this is quite hard to read, error-prone and difficult to test 
(apart from the fact that this code could be refactored anyways).

But it's not only about readability or stability but reusability:
Instead of copying all the tag-creation code from a view helper to 
create your custom version, you could extend the view helper and only 
modify or add some attributes of the underlying tag:

class LinkViewHelper extends TagBasedViewHelper {
	public function render($uri) {
		$this->tag->addAttribute('href', $uri);
	}
}

class SpeciallinkViewHelper extends LinkViewHelper {
	public function render() {
		$this->tag->addAttribute('rel', 'I\'m special');
	}
}


All the best
Bastian