How do i design classes when doing UI?

Question

I notice a pattern, when i did C++ and backend programming (in C# or any language) all my classes are neat and tidy. Recently i notice all my code are in a class and i literally have >50functions in it. I now realize its because i am doing UI. If i were to separate them by pages or forms/dialogs i would have a LOT MORE files, more lines of code and longer line of code. If i separate them i get the same problem (more files, lines, longer lines). Obviously the less lines the better (less code = less to debug, change or break during maintenance).

This specific project is 5k lines with 2k being from the web or libraries. All my .cs files are <1k lines. Is this acceptable even though i have 50+functions in a single class?

Bonus: I notice most of these functions are called only once. and putting certain code blocks (such as one function make two calls to the db) as their own function makes it harder for me to edit since they are divide between files and this balloon function count. So, i kind of dont know what to do. Do i create more classes to reduce function count (per class, it will increase function calls overall and already most are only called once)? How do i design classes doing frontend/UI?

Answer 1

I often find that my UI stuff grows considerably more complex than pure classes. Think about it - your "pure" classes are (for the most part) essentially machine instructions, and can (or should be able to) assume pure, pre-validated inputs and outputs, and do not have to accomodate the vagaries of human behavior.

A UI, on the other hand, is subject to all of human fallacy - and needs to respond in human-predictable ways, in a manner which humans can understand. THIS is where the complexity comes in.

Consider - in your nice, crisply defined classes, in which each function performs a fixed action against a known type of input, there is not alot of random BS to anticipate or handle.

A UI must be receptive to all manner of improper, inconsistent, or unanticipated input and actions by the user. While we, as designers, can pre-think some of this (and even minimize it with things like Combo-boxes and Command Buttons, a). all of that requires additional back-side code, and b) all of these things can then interact in different ways as well.

In our classes, WE decide how certain methods/functions and the like interact and affect one another. on the UI, we can do our best to point the user in the right direction, but there is still the random element. What if the user pushes the button before selecting an item from the list? There are several different ways to handle that scenario, all of which require another line (or ten, or 100) of code to handle gracefully.

Lastly, the more complex the project, the more complex the UI is likely to be, and the more of this must go on.

Managing the actions of the machine, given inputs and outpus we as programmers explicitly define, is EASY compared to predicting, managing, and handling the random quirks imposed on our stuff by a user. If only they would pay attention, right?

Anyway, I believe all of THAT is why code for a UI becomes greater, and more complex. As for how to break it out in a maintanable manner, the guys above covered it. Abstract the two. I design a form. I define the menas for the user to input data, and/or indicate what they want to happen next. Then I define the manner in which that form can communicate those things with my crisp, clean back end classes. Then I provide validation mechanisms, and the means to help control the user in navigating it all (eg the button is not enabled until the user selects an item from the list . . .).

Complex.