/**
* This is a quick class to get around JavaScript's
* poor support for associative arrays. Specifically,
* without this class, properties of the object would
* be included as keys in the associative array. This
* class ensures that we deal only with array elements
* we added to the array and not any properties of the
* container we're using. See Side Bar 1.
*
* $Horde: incubator/Horde_Form/js/simplehashtable.js,v 1.1 2005/08/18 04:47:46 mwarden Exp $
*
* Copyright 2005 Matt Warden <mwarden@gmail.com>
*
* See the enclosed file COPYING for license information (LGPL). If you
* did not receive this file, see http://www.fsf.org/copyleft/lgpl.html.
*
* @author Matt Warden <mwarden@gmail.com>
* @access public
*/
function SimpleHashtable()
{
this._data = new Object();
this._keys = new Array();
} // end constructor
function SimpleHashtable_count()
{
return this._keys.length;
}
/**
* Lisp-style method to call callback on every
* key-value pair of the array.
*
* @since 1.1
* @author Marcus <m-lists@bristav.se>
*/
function SimpleHashtable_each(callback)
{
for(var i=0 ; i<this._keys.length; i++) {
var key = this._keys[i];
callback(key, this.get(key));
}
} // end function SimpleHashtable_each
function SimpleHashtable_getKey(raw)
{
// python style naming convention,
// to avoid conflicts with actual
// attributes (see Side Bar 1).
return '__'+ raw +'__';
} // end function SimpleHashtable_getKey
function SimpleHashtable_get(nam)
{
var key = this.getKey(nam);
// retreive value if exists, else null
var val = (this._data[key]) ? this._data[key] : null;
return val;
} // end function SimpleHashtable_get
function SimpleHashtable_put(nam, val)
{
// if missing arg
if (!nam) return false;
var key = this.getKey(nam);
// if key doesn't already exist add
// to keys array.
var exists = true;
if (!this._data[key])
{
exists = false;
this._keys[this._keys.length] = nam;
}
// return old value if set, or else null
var oldval = exists ? this._data[key] : null;
this._data[key] = val;
return oldval;
} // end function SimpleHashtable_put
function SimpleHashtable_keys()
{
// return a copy of the array, otherwise
// the user of this class could accidentally
// modify our array, since we'd be passing
// them a reference.
return this._keys.slice(0);
} // end function SimpleHashtable_keys
function SimpleHashtable_containsKey(nam)
{
// get() returns null if not found
// or if found and is null. In both
// conditions, we want to return false.
// Otherwise, we want to return true.
return (this.get(nam) != null);
} // end function SimpleHashtable_containsKey
// creating the class this way is more memory efficient
// if we are using multiple instances of this data
// structure.
SimpleHashtable.prototype.getKey = SimpleHashtable_getKey;
SimpleHashtable.prototype.get = SimpleHashtable_get;
SimpleHashtable.prototype.put = SimpleHashtable_put;
SimpleHashtable.prototype.keys = SimpleHashtable_keys;
SimpleHashtable.prototype.count = SimpleHashtable_count;
SimpleHashtable.prototype.containsKey = SimpleHashtable_containsKey;
SimpleHashtable.prototype.each = SimpleHashtable_each;
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