Initial commit

php/pgadmin/libraries/decorator.inc.php

@@ -0,0 +1,233 @@
+<?php
+// $Id: decorator.inc.php,v 1.8 2007/04/05 11:09:38 mr-russ Exp $
+
+// This group of functions and classes provides support for
+// resolving values in a lazy manner (ie, as and when required)
+// using the Decorator pattern.
+
+###TODO: Better documentation!!!
+
+// Compatibility functions:
+if (!function_exists('is_a')) {
+	function is_a($object, $class) {
+		return is_object($object) && get_class($object) == strtolower($class) || is_subclass_of($object, $class);
+	}
+}
+
+// Construction functions:
+
+function field($fieldName, $default = null) {
+	return new FieldDecorator($fieldName, $default);
+}
+
+function merge(/* ... */) {
+	return new ArrayMergeDecorator(func_get_args());
+}
+
+function concat(/* ... */) {
+	return new ConcatDecorator(func_get_args());
+}
+
+function callback($callback, $params = null) {
+	return new CallbackDecorator($callback, $params);
+}
+
+function ifempty($value, $empty, $full = null) {
+	return new IfEmptyDecorator($value, $empty, $full);
+}
+
+function url($base, $vars = null /* ... */) {
+	// If more than one array of vars is given,
+	// use an ArrayMergeDecorator to have them merged
+	// at value evaluation time.
+	if (func_num_args() > 2) {
+		$v = func_get_args();
+		array_shift($v);
+		return new UrlDecorator($base, new ArrayMergeDecorator($v));
+	}
+	return new UrlDecorator($base, $vars);
+}
+
+function noEscape($value) {
+	if (is_a($value, 'Decorator')) {
+		$value->esc = false;
+		return $value;
+	}
+	return new Decorator($value, false);
+}
+
+function replace($str, $params) {
+	return new replaceDecorator($str, $params);
+}
+
+// Resolving functions:
+
+function value(&$var, &$fields, $esc = null) {
+	if (is_a($var, 'Decorator')) {
+		$val = $var->value($fields);
+		if (!$var->esc) $esc = null;
+	} else {
+		$val =& $var;
+	}
+	if (is_string($val)) {
+		switch($esc) {
+			case 'xml':
+				return strtr($val, array(
+					'&' => '&amp;',
+					"'" => '&apos;', '"' => '&quot;',
+					'<' => '&lt;', '>' => '&gt;'
+				));
+			case 'html':
+				return htmlspecialchars($val);
+			case 'url':
+				return urlencode($val);
+		}
+	}
+	return $val;
+}
+
+function value_xml(&$var, &$fields) {
+	return value($var, $fields, 'xml');
+}
+
+function value_xml_attr($attr, &$var, &$fields) {
+	$val = value($var, $fields, 'xml');
+	if (!empty($val))
+		return " {$attr}=\"{$val}\"";
+	else
+		return '';
+}
+
+function value_url(&$var, &$fields) {
+	return value($var, $fields, 'url');
+}
+
+// Underlying classes:
+
+class Decorator
+{
+	var $esc = true;
+	
+	function Decorator($value, $esc = true) {
+		$this->v = $value;
+		$this->esc = $esc;
+	}
+	
+	function value($fields) {
+		return $this->v;
+	}
+}
+
+class FieldDecorator extends Decorator
+{
+	function FieldDecorator($fieldName, $default = null) {
+		$this->f = $fieldName;
+		if ($default !== null) $this->d = $default;
+	}
+	
+	function value($fields) {
+		return isset($fields[$this->f]) ? $fields[$this->f] : (isset($this->d) ? $this->d : null);
+	}
+}
+
+class ArrayMergeDecorator extends Decorator
+{
+	function ArrayMergeDecorator($arrays) {
+		$this->m = $arrays;
+	}
+	
+	function value($fields) {
+		$accum = array();
+		foreach($this->m as $var) {
+			$accum = array_merge($accum, value($var, $fields));
+		}
+		return $accum;
+	}
+}
+
+class ConcatDecorator extends Decorator
+{
+	function ConcatDecorator($values) {
+		$this->c = $values;
+	}
+	
+	function value($fields) {
+		$accum = '';
+		foreach($this->c as $var) {
+			$accum .= value($var, $fields);
+		}
+		return trim($accum);
+	}
+}
+
+class CallbackDecorator extends Decorator
+{
+	function CallbackDecorator($callback, $param = null) {
+		$this->fn = $callback;
+		$this->p = $param;
+	}
+	
+	function value($fields) {
+		return call_user_func($this->fn, $fields, $this->p);
+	}
+}
+
+class IfEmptyDecorator extends Decorator
+{
+	function IfEmptyDecorator($value, $empty, $full = null) {
+		$this->v = $value;
+		$this->e = $empty;
+		if ($full !== null) $this->f = $full;
+	}
+	
+	function value($fields) {
+		$val = value($this->v, $fields);
+		if (empty($val))
+			return value($this->e, $fields);
+		else
+			return isset($this->f) ? value($this->f, $fields) : $val;
+	}
+}
+
+class UrlDecorator extends Decorator
+{
+	function UrlDecorator($base, $queryVars = null) {
+		$this->b = $base;
+		if ($queryVars !== null)
+			$this->q = $queryVars;
+	}
+	
+	function value($fields) {
+		$url = value($this->b, $fields);
+		
+		if ($url === false) return '';
+		
+		if (!empty($this->q)) {
+			$queryVars = value($this->q, $fields);
+			
+			$sep = '?';
+			foreach ($queryVars as $var => $value) {
+				$url .= $sep . value_url($var, $fields) . '=' . value_url($value, $fields);
+				$sep = '&';
+			}
+		}
+		return $url;
+	}
+}
+
+class replaceDecorator extends Decorator
+{
+	function replaceDecorator($str, $params) {
+		$this->s = $str;
+		$this->p = $params;
+	}
+
+	function value($fields) {
+		$str = $this->s;
+		foreach ($this->p as $k => $v) {
+			$str = str_replace($k, value($v, $fields), $str);
+		}
+		return $str;
+	}
+}
+?>