How do I know when do put my properties and messages in the .h file and when to put them in the .m interface?
I am thinking messages which are public like init should be in the .h file. What about properties which describe the class e.g. configuration type etc.
When you want to restrict access of any property, you can define that in .m file using class extension etc.
There is no as such rule defined for putting properties in .h or .m file, you need to check which properties you want to access outside the class(define those in .h) and which you do want to access outside(define in .m).