如何引用Objective-C类属性？

Question

I'm developing an application that have views with a lot of fields. I have been manipulating them one by one because I don't know how to reference class attributes to be able to dynamically save them.

Right now I have a lot of line of codes to manipulate a single field... For example:

self.rowField.delegate = self;

NSArray *collectionNames = @[@"personTypeCategories", @"personTypes", @"genders", @"rows", @"seats", @"seatingOthers", @"restraintSystems", @"helmetUses"];

if ([collectionName isEqualToString:@"personTypeCategories"]) {
    [self loadDefaultForCollection:@"personTypeCategories" toField:self.personTypeCategoryField withKey:@"PersonTypeCategoryID" defaultValue:self.editingPerson.typeCategoryKey];
}

if (textField == self.rowField) {
    [self showCollection:@"rows" withIDColumn:@"RowID" withField:textField];
    return NO;
} 

When I have a new field that follow our standard of saving information and later posting it to the server I need to create this lines for each one and now I want to do it dynamically by creating an array like this:

- (void)loadViewConfiguration {
    self.viewElements = [[NSMutableArray alloc] init];

    [self.viewElements addObject:@{
        @"restMethod" : @"personTypeCategories",
        @"key" : @"PersonTypeCategoryID",
        @"field" : self.personTypeCategoryField,
        @"enabled" : @YES,
        @"modelAttr" : &self.editingPerson.typeCategoryKey
    }];
}

The problem is in the modelAttr, I need to have that class attribute reference in order to later go and modify or get it.

Another option could be if I can dynamically call class attributes like you can do in PHP, for example:

$attr = "name";
$editingPerson->{$attr} = "Omar";

Thanks for the help.

Answer 1

I didn't know you can use key-value coding for this purpose.

To accomplish this what I did is to simply save the name of the attribute and later get the value by using:

[classInstance valueForKey:elem[@"modelAttr"]];

An example of this:

for (NSDictionary *elem in self.viewElements) {
       if ([collectionName isEqualToString:elem[@"restMethod"]]) {
                [self loadDefaultForCollection:elem[@"restMethod"] toField:elem[@"field"] withKey:elem[@"key"] defaultValue:[self.editingPerson valueForKey:elem[@"modelAttr"]]];
       }
}

Thanks for the advice by @matt