Make all controls to posses some additional properties and methods?

Question

My application is a form-designing application (the user can design their own form) so I want the like UITextField, UItextView, UIButton, UIImageView, etc. to posses some additional properties and methods. I know that I can subclass each control and add desired properties and methods. But I feel there may be some other easier way to achieve this.

Are there any other ways or is subclassing each control is the only way?

Answer 1

You can add additional properties to a category of an object using associated objects. it's to be used with caution but take a look here.

Answer 2

I think what you are trying to do is apply a theme to controls based on user choices. I don't think you need to change the elements themselves but apply a theme concept. The best solution I have found is to create an object that handles formatting, the user's choice and more. This is how I think you can implement it:

1. Create a formatter object extending NSObject

2. Have a property for each changeable piece of the theme:

   for example if the size of controls changes you can have a CG element in there. If the font color changes you have a UIFont property in there.

3. create a shared instance of your formater by adding:

   +(Formater *) sharedInstance; //add to .h
   
   
   + (Formater *) sharedInstance //add to .m
   {
       if (!_sharedInstance)
       {
           _sharedInstance = [[Formater alloc] init];
       }
   }
   

4. Now you can call the shared instance of the formater and use it's properties to set the properties of your elements. For example: If a user picked that UILabels should be of fontX and size 10. You set formater.labelFont = [UIFont fontWithName: fontX size:10];. Then every time you have a label you just set label.font = formater.labelFont]; If every UILabel can have a different size and font you just create a dictionary in your formater to hold that.