is the logic defining how the data should be converted in different formats, presentation or business logic?

Question

In a calendar app adopting a MVC architecture, the Model consists of objects representing the days of the week.

The View consists of labels displaying the days as strings or integers, depending on the user interaction.

Therefore I need some logic in my app for the mapping from strings to integers, and viceversa. Is this logic, business logic or presentation logic?

As first thought, I decided to include this logic to the View, because the format in which the data is displayed is a View responsibility.

However a second thought came to me, when I realised the mapping describes how data is manipulated and transformed, therefore it should be included in the Model, and not in the View.

Answer 1

It's presentation logic. Think about the string you are converting it to. What language is it in?

Business logic is the same regardless of language. You just need to know the date.

• aneuryzm: Ok. One more question: let's say I want to compute how many days has been since the beginning of the month. Is that business logic instead?
• Ewan: are you using it for presentation or is it part of the business logic?
• aneuryzm: From your comment I deduce that it can be both depending where I use it?
• Ewan: yes, anything can potentially be anywhere. for example maybe you have a business rule which says the prices change depending on the first letter of the day of the week. in that case it would be language dependent