Category is implementing a method which will also be implemented by its primary class ?

Question

I have Got this waning while using this code

-(void) drawPlaceholderInRect:(CGRect)rect {
    // [[UIColor ] setFill];

    BOOL currentdevice=[[UIDevice currentDevice].model hasPrefix:@"iPhone"];
    if(currentdevice)
    {
        [[self placeholder] drawInRect:rect withAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor],NSFontAttributeName:[UIFont fontWithName:@"OpenSans" size:15] }];

    }
    else
    {

        [[self placeholder] drawInRect:rect withAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor],NSFontAttributeName:[UIFont fontWithName:@"OpenSans" size:20]}];
    }

}

To Stop the warning message i am using this code

@implementation UITextField (placeholder)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wobjc-protocol-method-implementation"

// do your override
-(void) drawPlaceholderInRect:(CGRect)rect {
    // [[UIColor ] setFill];

    BOOL currentdevice=[[UIDevice currentDevice].model hasPrefix:@"iPhone"];
    if(currentdevice)
    {

        [[self placeholder] drawInRect:rect withAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor],NSFontAttributeName:[UIFont fontWithName:@"OpenSans" size:15] }];

    }
    else
    {

        [[self placeholder] drawInRect:rect withAttributes:@{NSForegroundColorAttributeName:[UIColor blackColor],NSFontAttributeName:[UIFont fontWithName:@"OpenSans" size:20]}];
    }

}


#pragma clang diagnostic pop

is there any problem if i use like this ..

or please give me exact way to override the method thanks....

Technically, it will work. It's better to avoid this, however, as technically the choice of which implementation will be used is not defined. — Avi, Dec 15 '15 at 12:19
Have a look at this answer http://stackoverflow.com/a/5272612/1186243 — sbarow, Dec 15 '15 at 12:20

Muhammad Adnan · Accepted Answer · 2015-12-15T13:18:56.873

0

For non UI customization its better to subclass. Assign TextField Class as CustomTextField where ever you require drawPlaceholderInRect as per your implementation

// CustomTextField.h

    #import <UIKit/UIKit.h>

    @interface CustomTextField : UITextField

    @end

//CustomTextField.m

#import "CustomTextField.h"

@implementation CustomTextField

- (void)drawPlaceholderInRect:(CGRect)rect {

    BOOL currentdevice=[[UIDevice currentDevice].model hasPrefix:@"iPhone"];
    if(currentdevice){
        NSDictionary *attrDictionary = @{
                                         NSForegroundColorAttributeName: [UIColor redColor],
                                         NSFontAttributeName : [UIFont fontWithName:@"OpenSans" size:15.0]
                                         };

        [[self placeholder] drawInRect:rect withAttributes:attrDictionary];

    }
    else{

        NSDictionary *attrDictionary = @{
                                         NSForegroundColorAttributeName: [UIColor redColor],
                                         NSFontAttributeName : [UIFont fontWithName:@"OpenSans" size:20.0]
                                         };

        [[self placeholder] drawInRect:rect withAttributes:attrDictionary];
    }

  }
@end

edited Dec 15 '15 at 13:18

answered Dec 15 '15 at 12:44

Muhammad Adnan

2,668
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but its didn't change the placeholder colour what to do bro @Muhammad – Kishore Kumar Dec 15 '15 at 12:57
are you subclassing TextField with CustomTextField? – Muhammad Adnan Dec 15 '15 at 13:04
are you setting CustomTextField as Class of your TextField in Storyboard or xib ? – Muhammad Adnan Dec 15 '15 at 13:19
One more thing have you set any placeholder text in Interface builder? – Muhammad Adnan Dec 15 '15 at 13:20
no i didn't set this custom class to to my textfield bro – Kishore Kumar Dec 15 '15 at 13:22
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/97985/discussion-between-kishore-kumar-and-muhammad). – Kishore Kumar Dec 15 '15 at 13:22
check edited Answer and image for subclassing textField – Muhammad Adnan Dec 15 '15 at 16:07

Category is implementing a method which will also be implemented by its primary class ?

1 Answers1