system/View/Parser.php
protected function parseConditionals(string $template): string
	{
		$pattern = '/\{\s*(if|elseif)\s*((?:\()?(.*?)(?:\))?)\s*\}/ms';

		/**
		 * For each match:
		 * [0] = raw match `{if var}`
		 * [1] = conditional `if`
		 * [2] = condition `do === true`
		 * [3] = same as [2]
		 */
		preg_match_all($pattern, $template, $matches, PREG_SET_ORDER);

		foreach ($matches as $match)
		{
			// Build the string to replace the `if` statement with.
			$condition = $match[2];

			$statement = $match[1] === 'elseif' ? '<?php elseif (' . $condition . '): ?>' : '<?php if (' . $condition . '): ?>';
			$template  = str_replace($match[0], $statement, $template);
		}

		$template = preg_replace('/\{\s*else\s*\}/ms', '<?php else: ?>', $template);
		$template = preg_replace('/\{\s*endif\s*\}/ms', '<?php endif; ?>', $template);

		// Parse the PHP itself, or insert an error so they can debug
		ob_start();
		extract($this->data);
		try
		{
			eval('?>' . $template . '<?php ');
		}
		catch (\ParseError $e)
		{
			ob_end_clean();
			throw ViewException::forTagSyntaxError(str_replace(['?>', '<?php '], '', $template));
		}
		return ob_get_clean();
	}
protected function parseConditionals(string $template): string
	{
		$pattern = '/\{\s*(if|elseif)\s*((?:\()?(.*?)(?:\))?)\s*\}/ms';

		/**
		 * For each match:
		 * [0] = raw match `{if var}`
		 * [1] = conditional `if`
		 * [2] = condition `do === true`
		 * [3] = same as [2]
		 */
		preg_match_all($pattern, $template, $matches, PREG_SET_ORDER);

		foreach ($matches as $match)
		{
			// Build the string to replace the `if` statement with.
			$condition = $match[2];

			$statement = $match[1] === 'elseif' ? '<?php elseif (' . $condition . '): ?>' : '<?php if (' . $condition . '): ?>';
			$template  = str_replace($match[0], $statement, $template);
		}

		$template = preg_replace('/\{\s*else\s*\}/ms', '<?php else: ?>', $template);
		$template = preg_replace('/\{\s*endif\s*\}/ms', '<?php endif; ?>', $template);

		// Parse the PHP itself, or insert an error so they can debug
		ob_start();
		extract($this->data);
		try
		{
			eval('?>' . $template . '<?php ');
		}
		catch (\ParseError $e)
		{
			ob_end_clean();
			throw ViewException::forTagSyntaxError(str_replace(['?>', '<?php '], '', $template));
		}
		return ob_get_clean();
	}
Parses any conditionals in the code, removing blocks that don't
pass so we don't try to parse it later.

Valid conditionals:
- if
- elseif
- else

@param string $template

@return string