cappuccino/Foundation/CPKeyValueCoding.j

/*
 * CPKeyValueCoding.j
 * Foundation
 *
 * Created by Francisco Tolmasky.
 * Copyright 2008, 280 North, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

import "CPObject.j"


var CPObjectAccessorsForClass   = nil,
    CPObjectModifiersForClass   = nil;

CPUndefinedKeyException     = @"CPUndefinedKeyException";
CPTargetObjectUserInfoKey   = @"CPTargetObjectUserInfoKey";
CPUnknownUserInfoKey        = @"CPUnknownUserInfoKey";

@implementation CPObject (CPKeyValueCoding)

+ (BOOL)accessInstanceVariablesDirectly
{
    return YES;
}

/* @ignore */
+ (SEL)_accessorForKey:(CPString)aKey
{
    if (!CPObjectAccessorsForClass)
        CPObjectAccessorsForClass = [CPDictionary dictionary];
    
    var hash = [isa hash],
        selector = nil,
        accessors = [CPObjectAccessorsForClass objectForKey:hash];
    
    if (accessors)
    {
        selector = [accessors objectForKey:aKey];
        
        if (selector)
            return selector == [CPNull null] ? nil : selector;
    }
    else
    {
        accessors = [CPDictionary dictionary];
        
        [CPObjectAccessorsForClass setObject:accessors forKey:hash];
    }

    var capitalizedKey = aKey.charAt(0).toUpperCase() + aKey.substr(1);
    
    if ([self instancesRespondToSelector:selector = CPSelectorFromString("get" + capitalizedKey)] || 
        [self instancesRespondToSelector:selector = CPSelectorFromString(aKey)] || 
        [self instancesRespondToSelector:selector = CPSelectorFromString("is" + capitalizedKey)] || 
        [self instancesRespondToSelector:selector = CPSelectorFromString("_get" + capitalizedKey)] || 
        [self instancesRespondToSelector:selector = CPSelectorFromString("_" + aKey)] || 
        [self instancesRespondToSelector:selector = CPSelectorFromString("_is" + capitalizedKey)])
    {
        [accessors setObject:selector forKey:aKey];
        
        return selector;
    }
    
    [accessors setObject:[CPNull null] forKey:aKey];
    
    return nil;
}

/* @ignore */
+ (SEL)_modifierForKey:(CPString)aKey
{
    if (!CPObjectModifiersForClass)
        CPObjectModifiersForClass = [CPDictionary dictionary];
    
    var hash = [isa hash],
        selector = nil,
        modifiers = [CPObjectModifiersForClass objectForKey:hash];
    
    if (modifiers)
    {
        selector = [modifiers objectForKey:aKey];
        
        if (selector)
            return selector == [CPNull null] ? nil : selector;
    }
    else
    {
        modifiers = [CPDictionary dictionary];
        
        [CPObjectModifiersForClass setObject:modifiers forKey:hash];
    }
    
    if (selector)
        return selector == [CPNull null] ? nil : selector;

    var capitalizedKey = aKey.charAt(0).toUpperCase() + aKey.substr(1) + ':';

    if ([self instancesRespondToSelector:selector = CPSelectorFromString("set" + capitalizedKey)] ||
        [self instancesRespondToSelector:selector = CPSelectorFromString("_set" + capitalizedKey)])
    {
        [modifiers setObject:selector forKey:aKey];
        
        return selector;
    }
    
    [modifiers setObject:[CPNull null] forKey:aKey];
    
    return nil;
}

/* @ignore */
- (CPString)_ivarForKey:(CPString)aKey
{
    var ivar = '_' + aKey;
    
    if (typeof self[ivar] != "undefined")
        return ivar;

    var isKey = "is" + aKey.charAt(0).toUpperCase() + aKey.substr(1);

    ivar = '_' + isKey;    
    
    if (typeof self[ivar] != "undefined")
        return ivar;
    
    ivar = aKey;
    
    if (typeof self[ivar] != "undefined")
        return ivar;
        
    ivar = isKey;
    
    if (typeof self[ivar] != "undefined")
        return ivar;

    return nil;
}
    
- (id)valueForKey:(CPString)aKey
{
    var selector = [isa _accessorForKey:aKey];

    if (selector)
        return objj_msgSend(self, selector);
    
    if([isa accessInstanceVariablesDirectly])
    {
        var ivar = [self _ivarForKey:aKey];
        
        if (ivar)
            return self[ivar];
    }
    
    return [self valueForUndefinedKey:aKey];
}
    
- (id)valueForKeyPath:(CPString)aKeyPath
{
    var keys = aKeyPath.split("."),
    
        index = 0,
        count = keys.length,
        
        value = self;

    for(; index < count; ++index)
        value = [value valueForKey:keys[index]];

    return value;
}

- (CPDictionary)dictionaryWithValuesForKeys:(CPArray)keys
{
    var index = 0,
        count = keys.length,
        dictionary = [CPDictionary dictionary];
    
    for (; index < count; ++index)
    {
        var key = keys[index],
            value = [self valueForKey:key];

        if (value === nil)
            [dictionary setObject:[CPNull null] forKey:key];
        else
            [dictionary setObject:value forKey:key];
    }
    
    return dictionary;
}

- (id)valueForUndefinedKey:(CPString)aKey
{
    [[CPException exceptionWithName:CPUndefinedKeyException
                            reason:[self description] + " is not key value coding-compliant for the key " + aKey
                          userInfo:[CPDictionary dictionaryWithObjects:[self, aKey] forKeys:[CPTargetObjectUserInfoKey, CPUnknownUserInfoKey]]] raise];
}
    
- (void)setValue:(id)aValue forKeyPath:(CPString)aKeyPath
{
    if (!aKeyPath) aKeyPath = "self";

    var i = 0,
        keys = aKeyPath.split("."),
        count = keys.length - 1,
        owner = self;

    for(; i < count; ++i) 
        owner = [owner valueForKey:keys[i]];
    
    [owner setValue:aValue forKey:keys[i]];
}
    
- (void)setValue:(id)aValue forKey:(CPString)aKey
{
    var selector = [isa _modifierForKey:aKey];

    if (selector)
        return objj_msgSend(self, selector, aValue);
    
    if([isa accessInstanceVariablesDirectly])
    {
        var ivar = [self _ivarForKey:aKey];
        
        if (ivar)
        {
            [self willChangeValueForKey:aKey];
            
            self[ivar] = aValue;
        
            [self didChangeValueForKey:aKey];
        }
        
        return;
    }
    
    [self setValue:aValue forUndefinedKey:aKey];
}
    
- (void)setValue:(id)aValue forUndefinedKey:(CPString)aKey
{
    [[CPException exceptionWithName:CPUndefinedKeyException
                            reason:[self description] + " is not key value coding-compliant for the key " + aKey
                          userInfo:[CPDictionary dictionaryWithObjects:[self, aKey] forKeys:[CPTargetObjectUserInfoKey, CPUnknownUserInfoKey]]] raise];
}

@end