CODEWITHSUNDEEP
iosobjective-creflectionuiview
Lena Bru
Lena Bru

Reputation: 13947

How to get all the properties of a ViewController that are subclasses of UIView

I want to use reflection to get all the properties of a ViewController, that are subclasses of UIView.

I have this method to get all the properties:

unsigned count;
objc_property_t *properties = class_copyPropertyList([self class], &count);

NSMutableArray *rv = [NSMutableArray array];

unsigned i;
for (i = 0; i < count; i++)
{
    objc_property_t property = properties[i];

    NSString *name = [NSString stringWithUTF8String:property_getName(property)];
    [rv addObject:name];
}

free(properties);

But how do I find which type this property is?

Upvotes: 1

Views: 463

Answers (2)

Sergey Demchenko
Sergey Demchenko

Reputation: 2954

You can find type via:

 const char * propertyAttrs = property_getAttributes(property);

The output will be like the following:

(lldb) p propertyAttrs
(const char *) $2 = 0x0065f74d "T@"UICollectionView",W,N,V_collectionView"

Where "T@"UICollectionView" is property type.

UPDATE

I've played with it. This code is not ideal and not tested well, but it works:

const char * property_getTypeString( objc_property_t property )
{
    const char * attrs = property_getAttributes( property );
    if ( attrs == NULL )
        return ( NULL );

    static char buffer[256];
    const char * e = strchr( attrs, ',' );
    if ( e == NULL )
        return ( NULL );

    int len = (int)(e - attrs);
    memcpy( buffer, attrs, len );
    buffer[len] = '\0';

    return ( buffer );
}


- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    unsigned count;
    objc_property_t *properties = class_copyPropertyList([self class], &count);

    NSMutableArray *rv = [NSMutableArray array];

    unsigned i;
    for (i = 0; i < count; i++)
    {
        objc_property_t property = properties[i];

        NSString *name = [NSString stringWithUTF8String:property_getName(property)];

        const char * typeString = property_getTypeString(property);

        NSString *type = [NSString stringWithUTF8String:typeString];

        NSCharacterSet *delimiters = [NSCharacterSet characterSetWithCharactersInString:@"\""];
        NSArray *splitString = [type componentsSeparatedByCharactersInSet:delimiters];

        Class classType = NSClassFromString(splitString[1]);

        BOOL result = [classType isSubclassOfClass:UIView.class];

        [rv addObject:name];
    }

    free(properties);

}

The function property_getTypeString is borrowed from here: https://github.com/AlanQuatermain/aqtoolkit

Upvotes: 1

Joshua
Joshua

Reputation: 2451

Maybe you can check runtime.h property_getAttributes(property_name)

as an example: 

 // will return what type the property is
  const char * propertyAttrs = property_getAttributes(property);

Upvotes: 0

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