modules/context/context.module

<?php
// $Id: context.module,v 1.5 2008/08/10 09:25:04 yhahn Exp $

define('CONTEXT_GET', 0);
define('CONTEXT_SET', 1);
define('CONTEXT_ISSET', 2);
define('CONTEXT_CLEAR', 3);

/**
 * Master context function. Avoid calling this directly -- use one of the helper functions below.
 *
 * @param $op
 *   The operation to perform - handled by the context helper functions. Use them.
 * @param $namespace
 *   A string to be used as the namespace for the context information.
 * @param $attribute
 *   Usually a string to be used as a key to set/retrieve context information. An array can
 *   also be used when setting context to establish an entire context namespace at once.
 *   (At some point objects may also be accepted, but currently functionaliy isn't complete.)
 * @param $value
 *   A value to set for the provided key. If omitted the value will be set to true.
 *
 * @return
 *   Either the requested value, or false if the operation fails.
 */
function context_context($op = CONTEXT_GET, $namespace = null, $attribute = null, $value = null) {
  static $context;
  $context = !$context ? array() : $context;
  switch ($op) {
    case CONTEXT_GET:
      // return entire context
      if (!$namespace) {
        return $context;
      }
      // return entire space if set
      else if (isset($context[(string) $namespace])) {
        // return val of key from space
        if (is_array($context[(string) $namespace]) && isset($context[(string) $namespace][(string) $attribute])) {
          return $context[(string) $namespace][(string) $attribute];
        }
        elseif (!$attribute){
          return $context[(string) $namespace];
        }
      }
      break;
    case CONTEXT_SET:
      // bail if invalid space is specified or context is already set
      if (is_string($namespace) || is_int($namespace)) {
        // initialize namespace if no key is specified
        if (!$attribute) {
          $context[(string) $namespace] = array();
          return true;
        }
        // set to true if key is a usable identifier. otherwise, allow a key or object to be inserted
        if (!$value) {
          if (is_string($attribute) || is_int($attribute)) {
            $context[(string) $namespace][(string) $attribute] = true;
            return true;
          }
          elseif (is_array($attribute) || is_object($attribute)) {
            $context[(string) $namespace] = $attribute;
            return true;
          }
        }
        // set value if key is valid
        if ((is_string($attribute) || is_int($attribute)) && $value) {
          $context[$namespace][$attribute] = $value;
          return true;
        }
      }
      break;
    case CONTEXT_ISSET:
      // return entire context
      if (!$namespace) return false;
      if (!$attribute) {
        // return entire space if set
        return isset($context[$namespace]);
      }
      // return val of key from space
      return isset($context[$namespace][$attribute]);
    case CONTEXT_CLEAR:
      $context = array();
      return true;
  }
  return false;
}

/**
 * Sets a context by namespace + attribute.
 */
function context_set($namespace, $attribute = null, $value = null) {
  return context_context(CONTEXT_SET, $namespace, $attribute, $value);
}

/**
 * Retrieves a context by namespace + (optional) attribute.
 */
function context_get($namespace = null, $attribute = null) {
  return context_context(CONTEXT_GET, $namespace, $attribute, null);
}

/**
 * Returns a boolean for whether a context namespace + attribute have been set.
 */
function context_isset($namespace = null, $attribute = null) {
  return context_context(CONTEXT_ISSET, $namespace, $attribute, null);
}

/**
 * Deprecated context_exists() function. Retained for backwards
 * compatibility -- please use context_isset() instead.
 */
function context_exists($namespace = null, $attribute = null) {
  return context_context(CONTEXT_ISSET, $namespace, $attribute, null);
}

/**
 * Clears static context array() -- meant only for testing
 */
function context_clear() {
  return context_context(CONTEXT_CLEAR);
}
1	<?php
2	// $Id: context.module,v 1.5 2008/08/10 09:25:04 yhahn Exp $
3
4	define('CONTEXT_GET', 0);
5	define('CONTEXT_SET', 1);
6	define('CONTEXT_ISSET', 2);
7	define('CONTEXT_CLEAR', 3);
8
9	/**
10	* Master context function. Avoid calling this directly -- use one of the helper functions below.
11	*
12	* @param $op
13	* The operation to perform - handled by the context helper functions. Use them.
14	* @param $namespace
15	* A string to be used as the namespace for the context information.
16	* @param $attribute
17	* Usually a string to be used as a key to set/retrieve context information. An array can
18	* also be used when setting context to establish an entire context namespace at once.
19	* (At some point objects may also be accepted, but currently functionaliy isn't complete.)
20	* @param $value
21	* A value to set for the provided key. If omitted the value will be set to true.
22	*
23	* @return
24	* Either the requested value, or false if the operation fails.
25	*/
26	function context_context($op = CONTEXT_GET, $namespace = null, $attribute = null, $value = null) {
27	static $context;
28	$context = !$context ? array() : $context;
29	switch ($op) {
30	case CONTEXT_GET:
31	// return entire context
32	if (!$namespace) {
33	return $context;
34	}
35	// return entire space if set
36	else if (isset($context[(string) $namespace])) {
37	// return val of key from space
38	if (is_array($context[(string) $namespace]) && isset($context[(string) $namespace][(string) $attribute])) {
39	return $context[(string) $namespace][(string) $attribute];
40	}
41	elseif (!$attribute){
42	return $context[(string) $namespace];
43	}
44	}
45	break;
46	case CONTEXT_SET:
47	// bail if invalid space is specified or context is already set
48	if (is_string($namespace) \|\| is_int($namespace)) {
49	// initialize namespace if no key is specified
50	if (!$attribute) {
51	$context[(string) $namespace] = array();
52	return true;
53	}
54	// set to true if key is a usable identifier. otherwise, allow a key or object to be inserted
55	if (!$value) {
56	if (is_string($attribute) \|\| is_int($attribute)) {
57	$context[(string) $namespace][(string) $attribute] = true;
58	return true;
59	}
60	elseif (is_array($attribute) \|\| is_object($attribute)) {
61	$context[(string) $namespace] = $attribute;
62	return true;
63	}
64	}
65	// set value if key is valid
66	if ((is_string($attribute) \|\| is_int($attribute)) && $value) {
67	$context[$namespace][$attribute] = $value;
68	return true;
69	}
70	}
71	break;
72	case CONTEXT_ISSET:
73	// return entire context
74	if (!$namespace) return false;
75	if (!$attribute) {
76	// return entire space if set
77	return isset($context[$namespace]);
78	}
79	// return val of key from space
80	return isset($context[$namespace][$attribute]);
81	case CONTEXT_CLEAR:
82	$context = array();
83	return true;
84	}
85	return false;
86	}
87
88	/**
89	* Sets a context by namespace + attribute.
90	*/
91	function context_set($namespace, $attribute = null, $value = null) {
92	return context_context(CONTEXT_SET, $namespace, $attribute, $value);
93	}
94
95	/**
96	* Retrieves a context by namespace + (optional) attribute.
97	*/
98	function context_get($namespace = null, $attribute = null) {
99	return context_context(CONTEXT_GET, $namespace, $attribute, null);
100	}
101
102	/**
103	* Returns a boolean for whether a context namespace + attribute have been set.
104	*/
105	function context_isset($namespace = null, $attribute = null) {
106	return context_context(CONTEXT_ISSET, $namespace, $attribute, null);
107	}
108
109	/**
110	* Deprecated context_exists() function. Retained for backwards
111	* compatibility -- please use context_isset() instead.
112	*/
113	function context_exists($namespace = null, $attribute = null) {
114	return context_context(CONTEXT_ISSET, $namespace, $attribute, null);
115	}
116
117	/**
118	* Clears static context array() -- meant only for testing
119	*/
120	function context_clear() {
121	return context_context(CONTEXT_CLEAR);
122	}