s9e\TextFormatter\Configurator\Helpers\TemplateHelper::replaceTokens()

Complexity

Conditions	13
Paths	57

Size

Total Lines	128
Code Lines	57

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

<?php
	public static function replaceTokens($template, $regexp, $fn)
	{
		if ($template === '')
		{
			return $template;
		}

		$dom   = self::loadTemplate($template);
		$xpath = new DOMXPath($dom);

		// Replace tokens in attributes
		foreach ($xpath->query('//@*') as $attribute)
		{
			// Generate the new value
			$attrValue = preg_replace_callback(
				$regexp,
				function ($m) use ($fn, $attribute)
				{
					$replacement = $fn($m, $attribute);

					if ($replacement[0] === 'expression')
					{
						return '{' . $replacement[1] . '}';
					}
					elseif ($replacement[0] === 'passthrough')
					{
						return '{.}';
					}
					else
					{
						// Literal replacement
						return $replacement[1];
					}
				},
				$attribute->value
			);

			// Replace the attribute value
			$attribute->value = htmlspecialchars($attrValue, ENT_COMPAT, 'UTF-8');
		}

		// Replace tokens in text nodes
		foreach ($xpath->query('//text()') as $node)
		{
			preg_match_all(
				$regexp,
				$node->textContent,
				$matches,
				PREG_SET_ORDER | PREG_OFFSET_CAPTURE
			);

			if (empty($matches))
			{
				continue;
			}

			// Grab the node's parent so that we can rebuild the text with added variables right
			// before the node, using DOM's insertBefore(). Technically, it would make more sense
			// to create a document fragment, append nodes then replace the node with the fragment
			// but it leads to namespace redeclarations, which looks ugly
			$parentNode = $node->parentNode;

			$lastPos = 0;
			foreach ($matches as $m)
			{
				$pos = $m[0][1];

				// Catch-up to current position
				if ($pos > $lastPos)
				{
					$parentNode->insertBefore(
						$dom->createTextNode(
							substr($node->textContent, $lastPos, $pos - $lastPos)
						),
						$node
					);
				}
				$lastPos = $pos + strlen($m[0][0]);

				// Remove the offset data from the array, keep only the content of captures so that
				// $_m contains the same data that preg_match() or preg_replace() would return
				$_m = [];
				foreach ($m as $capture)
				{
					$_m[] = $capture[0];
				}

				// Get the replacement for this token
				$replacement = $fn($_m, $node);

				if ($replacement[0] === 'expression')
				{
					// Expressions are evaluated in a <xsl:value-of/> node
					$parentNode
						->insertBefore(
							$dom->createElementNS(self::XMLNS_XSL, 'xsl:value-of'),
							$node
						)
						->setAttribute('select', $replacement[1]);
				}
				elseif ($replacement[0] === 'passthrough')
				{
					// Passthrough token, replace with <xsl:apply-templates/>
					$parentNode->insertBefore(
						$dom->createElementNS(self::XMLNS_XSL, 'xsl:apply-templates'),
						$node
					);
				}
				else
				{
					// Literal replacement
					$parentNode->insertBefore($dom->createTextNode($replacement[1]), $node);
				}
			}

			// Append the rest of the text
			$text = substr($node->textContent, $lastPos);
			if ($text > '')
			{
				$parentNode->insertBefore($dom->createTextNode($text), $node);
			}

			// Now remove the old text node
			$parentNode->removeChild($node);
		}

		return self::saveTemplate($dom);
	}

}