openrat-cms

VariableResolver.class.php (5263B)

---

 <?php
 
 
 namespace util\text\variables;
 
 /**
  * VariableResolver for resolving variables in strings and arrays.
  */
 
 class VariableResolver
 {
 	public $marker   = '$';
 	public $open     = '{';
 	public $close    = '}';
 	public $namespaceSeparator  = '.';
 	public $defaultSeparator    = ':';
 	public $renderOnlyVariables = false;
 
 	/**
 	 * @var callable
 	 */
 	private $filterValue = null;
 
 	private $resolvers = [];
 
 	private $value = null;
 
 
 	/**
 	 * Adding a filter function for values.
 	 * @param $filter callable
 	 */
 	public function addFilter( $filter ) {
 		$this->filterValue = $filter;
 	}
 
 	/**
 	 * Adding a default variable resolver.
 	 * @param $resolver callable|array
 	 */
 	public function addDefaultResolver( $resolver ) {
 		$this->resolvers[''] = $resolver;
 	}
 
 	/**
 	 * Adding a variable resolver for a key.
 	 *
 	 * @param $key string key
 	 * @param $resolver callable|array
 	 */
 	public function addResolver( $key, $resolver ) {
 		$this->resolvers[$key] = $resolver;
 	}
 
 
 	/**
 	 * Resolving a variable in a text like 'name is ${env:username:default}.'
 	 *
 	 * @param $value string
 	 * @return string
 	 */
 	public function resolveVariables($value) {
 
 		$this->parseString( $value );
 		return $this->renderToString();
 	}
 
 	/**
 	 * Resolving a variable in a text like 'name is ${env.username:default}.'
 	 *
 	 * @param $value array
 	 * @return array
 	 */
 	public function resolveVariablesInArray($value) {
 
 		// pass-by-reference
 		array_walk_recursive($value, function (&$item, $keyI) {
 
 			$item = $this->resolveVariables($item);
 			return $item;
 		});
 
 		return $value;
 
 	}
 
 	/**
 	 * Resolving a variable in a text like 'name is ${env:username:default}'.
 	 *
 	 * @param $value
 	 * @param $key
 	 * @param $resolver
 	 * @return string
 	 */
 	public function parseString($value)
 	{
 		$this->value = $this->parseToValue($value);
 	}
 
 	public function renderToString()
 	{
 		return $this->render( $this->value );
 	}
 
 
 
 	protected function render( $value )
 	{
 		$text = '';
 
 		foreach( $value->expressions as $expression )
 		{
 			if   ( $expression instanceof ValueExpression ) {
 				$key = $this->render($expression->prefix);
 				$resolver = @$this->resolvers[ $key ];
 				$v = '';
 				if   ( is_callable($resolver) ) {
 					$v = $resolver( $this->render($expression->name) );
 				}
 				elseif   ( is_array($resolver) ) {
 					$v = @$resolver[ $this->render($expression->name ) ];
 				}
 				if   ( strlen($v)==0 )
 					$v = $this->render($expression->default);
 
 				if   ( $this->filterValue ) {
 					$filter = $this->filterValue;
 					$v = $filter( $v );
 				}
 
 				$text .= $v;
 			}else {
 				$text .= strval( $expression );
 			}
 		}
 
 		return $text;
 	}
 
 
 	private function findNextPosOfChar( $haystack, $needle ) {
 
 		$chars = str_split($haystack);
 		$depth = 0;
 		$pos   = 0;
 		foreach( $chars as $char) {
 
 			if   ( $char == $this->open )
 				$depth++;
 			elseif   ( $char == $needle && $depth == 0 )
 				return $pos;
 			elseif   ( $char == $this->close )
 				$depth--;
 
 			$pos++;
 		}
 
 		return false;
 
 	}
 
 	/**
 	 * @param $inputText
 	 * @return Value
 	 */
 	public function parseToValue($inputText)
 	{
 		$v = new Value();
 
 		while (true) {
 
 			if	( strlen($inputText)==0 ) // Do not compare to "false" here, as '0' is false ;)
 				break;
 
 			// Search the next variable marker '$'
 			$nextVariableMarkerPos = strpos($inputText, $this->marker.$this->open);
 
 			if   ($nextVariableMarkerPos === false )
 			{
 				// no variable found.
 				$v->expressions[] = $inputText;
 				break;
 			}
 			else
 			{
 				$v->expressions[] = substr($inputText,0,$nextVariableMarkerPos);
 
 				$inputText = substr($inputText,$nextVariableMarkerPos+strlen($this->marker)+strlen($this->open));
 
 				$pos = $this->findNextPosOfChar($inputText,$this->close);
 
 				if   ( $pos  === false)
 					throw new \RuntimeException('non-closed variable: '.$inputText);
 
 				$vv = substr($inputText,0,$pos);
 				$namespace = '';
 				$default   = '';
 
 				$prefixSepPos = $this->findNextPosOfChar($vv,$this->namespaceSeparator);
 				if   ( $prefixSepPos!==false) {
 					$namespace = substr($vv,0,$prefixSepPos);
 					$vv        = substr($vv,$prefixSepPos+strlen($this->namespaceSeparator));
 				}
 
 				$defaultSepPos = $this->findNextPosOfChar($vv,$this->defaultSeparator);
 				if   ( $defaultSepPos!==false) {
 					$default = substr($vv,$defaultSepPos+strlen($this->defaultSeparator));
 					$vv      = substr($vv, 0,$defaultSepPos);
 				}
 
 				$v->expressions[] = new ValueExpression($this->parseToValue($namespace),$this->parseToValue($vv),$this->parseToValue($default));
 
 				$inputText = substr($inputText,$pos+1);
 			}
 
 		}
 
 		return $v;
 	}
 
 
 	public function createExpression($namespace, $name, $default='')
 	{
 		return $this->marker.$this->open.($namespace?$namespace.$this->namespaceSeparator:'').$name.($default?$this->defaultSeparator.$default:'').$this->close;
 	}
 }
 
 /** Usage: *
 
 $resolver = new VariableResolver();
 print_r( $resolver->resolveVariables('Born in the ${bruce:birthcountry}.','bruce',function($name){return 'USA';} ) );
 print_r( $resolver->resolveVariables('Born in ${bruce:birthyear:19??}.','bruce',function($name){return '';} ) );
 print_r( $resolver->resolveVariables('Born in the ${bruce:birthcountry}.${x:y}${x}','bruce',function($name){return 'USA';} ) );
 exit;
 */