UI First or logic first? - iphone

While working on projects, I often come to the dilemma of working on UI first or on logic first. Having UI first gives a nice overview of how the end product is going to look like whilehaving logic first uncovers any possible roadblocks in technology.
However, it is not always that crystal clear.. some times UI may need data to be populated to really show what it means and simulating the data could be more difficult than inplementing the logic.. what is your preferred approach for development and why? Which is more efficient and effective?
( I am seeing this issue more and more with iphone projects)


Neither.
You will have to so some thinking at the beginning of the project anyway, deciding the general approach you will take and what operations you will support.
Do that reasonably well and you will have defined the interface between the view and the underlying logic. Look at the Model-View-Controller approach for some inspiration.
What you want to have early on is an idea of what are the basic operations your logic code needs to do to in order to achieve a purpose. Usually it will be a simple function call but sometimes it may involve more than that. Have that clear first.
Next, a complex system that works is based on a simple system that works.
Which means you will need to have a basic UI you'll use to test a basic logic implementation first.
A simple form with a button which presents a message is basic enough. Then, it can grow, you implement a piece of functionality and then you add a simple UI you can test it with.
It is easier to do both piece by piece as the logic and UI for a small piece of the logic are conceptually similar and it will be easy to keep track of both while you implement and test.
The most important part is to keep the UI and logic decoupled, making them talk through a common interface. This will allow you to make quick edits when needed and improve the looks of the GUI towards the end.
You will be better able to just scrap the UI if you don't like it. All you'll need to do is use the same interface, one which you know how to do because you wrote it and you already implemented it.
If at some point you realize you've made a big mistake you can still salvage parts of the code, again because the UI and logic are decoupled and, hopefully, the logic part is also modular enough.
In short: think first, do both the UI and the logic in small increments and keep things modular.


Iterate between both (logic and UI). Back and forth. The UI may change as you understand how and what you can do with the logic and whatever constraints that may present. The logic may change as you change the features, behavior, or performance requirements of an easy-to-use, responsive, and decent looking UI.
I usually do the minimum possible of each until I have some barely working mockups. Then I use each mockup to test where my assumptions about the proper UI and/or logic might be right or wrong. Pick the most flawed, and start iterating.
Apple suggests mocking up the UI on paper first. (Have an eraser handy...)


If possible, in parallel.
But personally, I advocate logic first.


I start with the fundamentals first and that means getting the logic coded and working first. There are two reasons for this:
If I can't get the logic working correctly having a pretty UI is useless and a waste of my time
You will most likely change the UI when you work on the logic aspect making the UI process longer and more expensive


I usually get my UI in order first. The reason? As I prototype different designs, sometimes my idea for the app changes. If it does, then it's no consequence - there is no code to rewrite.
However, sometimes it is helpful to get the fundamentals first in order to determine if the app is going to work or not. If it's not going to function, then why waste time making interfaces?


I like to start by laying out the different parts of my project in something like Vizio.
I make boxes for the different views I expect to have, and I fill them with the information I expect them to contain.
I make another set of boxes for my expected model objects (logic). I fill them with the information I expect they will work with, and I draw lines between models and views where I think it will be necessary.
I do the same thing for object graphs (if I plan on using CoreData), and for database tables if I am going to have an external database.
Laying everything out visually helps me decide if I am missing any important features or interactions between project components. It also gives me something to quickly refer to if I later lose track of what I was doing.
From that point, I tend to work on a model until it has enough done to fill out part of a view, then I work on a view until it can interact with the model.
I also try to identify views or models that could be reused for multiple purposes so that I can reduce the overall amount of work I have to do.


Take the agile approach and work on small amounts of both in iterations. Slowly building each functional piece of the program so as to not build any monolithic piece at once.

Related

Is there a way to import common feature file to another feature file in cucumber

Is there a way to import one cucumber feature file to another? so that I can move my repeated logics/actions/business validations for different flow to a common feature file.
Note: am using the background option effectively for few things like launching the application in every feature file. if consider it, even that background is also duplicated. :)
Many Thanks.

There is no way to include one feature file in another.
If you could, then Gherkin could be considered to be a programming language. Gherkin isn't a programming language and thus lacks features like functions or modules.
What can you do about your repeated backgrounds then? My approach would probably be to see if I could move the common initialization you do in the background down the stack. I would see if I could implement some helpers that would perform the same steps and then either minimize the background to something like
Given the world is prepared
in a background. Or just make sure that the preparation was done first in the scenarios that needed it. Maybe even hide it so the call is done in the first step. This would essentially move the background away from the feature file and hide it from for your business stakeholders.
One thing to consider tho would be, is the background important for your business stakeholders? Do they care about the backgrounds or is it just noise for them? If it is important, then don't hide the backgrounds. If the backgrounds isn't important, then hide them as much as possible.

You can deal with this by abstraction and background.
Given any number of prerequisites, if you group them together and give them a name you can call them in one step. In the cucumber space its far more effective to do this rather than import.
BDD is all about working at different levels of abstraction. In particular when you create some specific behaviour you work at a detailed level. Once the behaviour is created you then use that behaviour in a more abstract way.
Importing just gives you access to the detail. This is a bad thing because you end up working with different levels of abstraction in the same place which is both dangerous and confusing.

Designing a iPhone application

I am into designing a new iPhone application. My application is will contain almost all iPhone SDK concepts including core data, server integration, location services. Is there any design decisions I should keep in mind?
My plan was to go by designing a controller class for each iPhone app screen and also any utility classes to be used. Any guidance will be really appreciated.

I forget who said this first, but it goes like this: The first project you do in any new technology will probably be very bad!
This is similar to these sage words from Fred Brooks - "Plan to throw one away; you will anyway"
So the best way is to wade right in, get dirty, light up the dark corners and learn what works for you. Then you'll most likely have some very specific questions based on your experiences!

This is a tough subject to talk about generally. Design approaches that work for some will fail for others.
It would probably help to know more about what you are trying to do. For a counter-example, I'm working on a game. I create an OpenGL context and from that moment on I'm managing assets like shaders, textures, mesh data, sounds,... . The way I've designed my project will pretty much be useless to you.
However the best advice that I can come up is to really figure out what you are trying to do. Create mockups of your GUI and document workflows. Do sketches of GUIs. Become an expert in the domain in which you want your application to work. Develop a deep understanding of what you are trying to do.
Once you have the GUI figured out, start working on the other end of the Model-View-Controller approach - figure out what data you need in order to provide the GUI that you've designed. Not all data structures are equal. What's the best data design for the domain you're working on?
Once you have the view and model figured out you need to glue everything together with controllers. There's lots of trick and traps here. Do you use threading to prevent the GUI from blocking? Do you make direct calls to objects or do you decouple and use notifications?
But this is the public appearance of your application. You might want to track usage data - consider what you wish to track and append that to your design. Errors happen, so think how to approach them.
However, it's hard to be more detailed without more details than what you've provided. Every application has it's own quirks and gotchas. It's nearly impossible to talk about this in a general sense.

Reuse vs. maintainability and ease of testing

Everyone likes to talk about reusability. Where I work, whenever some new idea is being tossed around or tested out, the question of reusability always comes up. "We want to maximize our investment in this, let's make it reusable." "Reusability will bring higher quality with less work." And so on and so on.
What I've found is that when a reusable component or idea is introduced, everyone is immediately afraid of it and writes it off as a bad idea. Once applications become dependent on it, they say, it won't be maintainable, and any changes will result in the need to do regression testing on everything that uses it. People here point to one component in particular that has been around a long time and has a whole lot of dependents and grouse that it's become impossible to change becuase we don't know what the changes will break.
My responses to this complaint are:
It's good that change to a component
that has many dependents is slow,
because it forces the designers to
really think through the changes.
Time should be taken to get the
component right in the first place. Corrollary: If you're finding the need to change it all the time, it was never very reusable to begin with, was it?
Software development is hard and requires work. So does testing. You just gotta do it.
Unfortunately, what people hear in these responses are "slow," "time" and "effort."
I would love if there was a magic "make this reusable" switch I could flip on things I build so as to win brownie points from management, but things don't work that way. Making something reusable takes time and effort and you're still not guaranteed to get it right.
How do you deal with the request for "reusability" when delivering on it seems to bring nothing but complaints?

Reusability is only worthwhile if something will actually be reused. Make sure you have some practical reuse cases before you write something reusable.
Even if a reusable library is 10x harder to maintain than an ad-hoc version of itself, you're still saving on maintenance overall if the reusable library is used in place of ad-hoc versions in 10 different places.

Reusability is to make code reusable in term of similar behavior or "IS_A" relationship. If you just want to reuse code block by seeing them using again and again but they have no similar characteristic, you should better leave them alone to be loosely coupling. By that, we can have more flexibility to modify later.

One thing that we often do is to use versions and avoid the constant retesting. Just because there is a new version of common code doesn't mean everything has to use the new version right away. When something is getting updated for other reasons, update to the new version of the common code.

Is Microsoft Workflow Foundation really used?

Today, I had a training on "Microsoft Workflow Foundation".
While I think the idea is neat, I still see it as a Proof Of Concept and not as a real-life solution. Building an entire application without having to type a single line of code (or only a few of them) seems just wrong.
Have you ever used this technology and if so, can it really fit to big company projects ? What drawbacks/advantages have you got using it ?

I don't see it replacing an entire application, but more likely used in the architecture of an application to make it easier to maintain and build, since business logic is separated out.
In previous application I've built, we used our own workflow solution to make our site easier to maintain and also to add new content and controls quickly without recompiling & redeploying.
MWF can definitely have a place in even small applications, depending on it's needs.

Workflow is just a part of a larger application, just like your entire app isn't WPF or ADO. And it is certainly used in real applications and very useful. Things to look for where it is a good fit are items that behave as small projects in an applications like a sales orders, hiring a new person or building a house. All thee have a start, go through multiple steps, have an ending and you are likely to manage multiple in your application. Describe the "project" steps in one or more workflows and start one for each occurrence.
As this is a very common occurrence I believe far more developers could benefit from using workflow in their applications.

Lately I've been using it to replace those parts of the codebase that are really messy as far as the branching and looping logic is concerned. When you can visualize that stuff in a picture, and just create some custom activities to perform your logic, it makes knowing exactly what is going on much easier.
The entire application wasn't rewritten, for example there's really no reason to do any CRUD type operations with workflow, but its been very helpful for some of the "heavy lifting" operations.

Getting your head around other people's code

I'm occasionally unfortunate enough to have to make alterations to very old, poorly not documented and poorly not designed code.
It often takes a long time to make a simple change because there is not much structure to the existing code and I really have to read a lot of code before I have a feel for where things would be.
What I think would help a lot in cases like this is a tool that would allow one to visualise an overview of the code, and then maybe even drill down for more detail. I suspect such a tool would be very hard to get right, given that is trying to find structure where there is little or none.
I guess this is not really a question, but rather a musing. I should make it into a question - What do others do to assist in getting their head around other peoples code, the good and the bad?

Hmm, this is a hard one, so much to say so little time ...
1) If you can run the code it makes life soooo much easier, breakpoints (especially conditional) break points are you friend.
2) A purists' approach would be to write a few unit tests, for known functionality, then refactor to improve code and understanding, then re-test. If things break, then create more unit tests - repeat until bored/old/moved to new project
3) ReSharper is good at showing where things are being used, what's calling a method for instance, it's static but a good start, and it helps with refactoring.
4) Many .net events are coded as public, and events can be a pain to debug at the best of times. Recode them to be private and use a property with add/remove. You can then use break point to see what is listening on an event.
BTW - I'm playing in the .Net space, and would love a tool to help do this kind of stuff, like Joel does anyone out there know of a good dynamic code reviewing tool?

I have been asked to take ownership of some NASTY code in the past - both work and "play".
Most of the amateurs I took over code for had just sort of evolved the code to do what they needed over several iterations. It was always a giant incestuous mess of library A calling B, calling back into A, calling C, calling B, etc. A lot of the time they'd use threads and not a critical section was to be seen.
I found the best/only way to get a handle on the code was start at the OS entry point [main()] and build my own call stack diagram showing the call tree. You don't really need to build a full tree at the outset. Just trace through the section(s) you're working on at each stage and you'll get a good enough handle on things to be able to run with it.
To top it all off, use the biggest slice of dead tree you can find and a pen. Laying it all out in front of you so you don't have to jump back and forward on screens or pages makes life so much simpler.
EDIT: There's a lot of talk about coding standards... they will just make poor code look consistent with good code (and usually be harder to spot). Coding standards don't always make maintaining code easier.

I do this on a regular basis. And have developed some tools and tricks.
Try to get a general overview (object diagram or other).
Document your findings.
Test your assumptions (especially for vague code).
The problem with this is that on most companies you are appreciated by result. That's why some programmers write poor code fast and move on to a different project. So you are left with the garbage, and your boss compares your sluggish progress with the quick and dirtu guy. (Luckily my current employer is different).

I generally use UML sequence diagrams of various key ways that the component is used. I don't know of any tools that can generate them automatically, but many UML tools such as BoUML and EA Sparx can create classes/operations from source code which saves some typing.

The definitive text on this situation is Michael Feathers' Working Effectively with Legacy Code. As S. Lott says get some unit tests in to establish behaviour of the lagacy code. Once you have those in you can begin to refactor. There seems to be a sample chapter available on the Object Mentor website.

I strongly recommend BOUML. It's a free UML modelling tool, which:
is extremely fast (fastest UML tool ever created, check out benchmarks),
has rock solid C++ import support,
has great SVG export support, which is important, because viewing large graphs in vector format, which scales fast in e.g. Firefox, is very convenient (you can quickly switch between "birds eye" view and class detail view),
is full featured, intensively developed (look at development history, it's hard to believe that so fast progress is possible).
So: import your code into BOUML and view it there, or export to SVG and view it in Firefox.

See Unit Testing Legacy ASP.NET Webforms Applications for advice on getting a grip on legacy apps via unit testing.
There are many similar questions and answers. Here's the search https://stackoverflow.com/search?q=unit+test+legacy
The point is that getting your head around legacy is probably easiest if you are writing unit tests for that legacy.

I haven't had great luck with tools to automate the review of poorly documented/executed code, cause a confusing/badly designed program generally translates to a less than useful model. It's not exciting or immediately rewarding, but I've had the best results with picking a spot and following the program execution line by line, documenting and adding comments as I go, and refactoring where applicable.

a good IDE (EMACS or Eclipse) could help in many cases. Also on a UNIX-platform, there are some tools for crossreferencing (etags, ctags) or checking (lint) or gcc with many many warning options turned on.
First, before trying to comprehend a function/method, i would refactor it a bit to fit your coding conventions (spaces, braces, indentation) and remove most of the comments if they seem to be wrong.
Then I would refactor and comment the parts you understood, and try to find/grep those parts over the whole source tree and refactor them there also.
Over the time, you get a nicer code, you like to work with.

I personally do a lot of drawing of diagrams, and figuring out the bones of the structure.
The fad de jour (and possibly quite rightly) has got me writing unit tests to test my assertions, and build up a safety net for changes I make to the system.
Once I get to a point where I'm comfortable enought knowing what the system does, I'll take a stab at fixing bugs in the sanest way possible, and hope my safety nets neared completion.
That's just me, however. ;)

i have actuaally been using the refactoring features of ReSharper to help m get a handle on a bunch of projects that i inherited recently. So, to figure out another programmer's very poorly structured, undocumented code, i actually start by refactoring it.
Cleaning up the code, renaming methods, classes and namespaces properly, extracting methods are all structural changes that can shed light on what a piece of code is supposed to do. It might sound counterintuitive to refactor code that you don't "know" but trut me, ReSharper really allows you to do this. Take for example the issue of red herring dead code. You see a method in a class or perhaps a strangely named variable. You can start by trying to lookup usages or, ungh, do a text search, but ReSharper will actually detect dead code and color it gray. As soon as you open a file you see in gray and with scroll bar flags what would have in the past been confusing red herrings.
There are dozens of other tricks and probably a number of other tools that can do similar things but i am a ReSharper junky.
Cheers.

Get to know the software intimately from a user's point of view. A lot can be learnt about the underlying structure by studying and interacting with the user interface(s).

Printouts
Whiteboards
Lots of notepaper
Lots of Starbucks
Being able to scribble all over the poor thing is the most useful method for me. Usually I turn up a lot of "huh, that's funny..." while trying to make basic code structure diagrams that turns out to be more useful than the diagrams themselves in the end. Automated tools are probably more helpful than I give them credit for, but the value of finding those funny bits exceeds the value of rapidly generated diagrams for me.
For diagrams, I look for mostly where the data is going. Where does it come in, where does it end up, and what does it go through on the way. Generally what happens to the data seems to give a good impression of the overall layout, and some bones to come back to if I'm rewriting.

When I'm working on legacy code, I don't attempt to understand the entire system. That would result in complexity overload and subsequent brain explosion.
Rather, I take one single feature of the system and try to understand completely how it works, from end to end. I will generally debug into the code, starting from the point in the UI code where I can find the specific functionality (since this is usually the only thing I'll be able to find at first). Then I will perform some action in the GUI, and drill down in the code all the way down into the database and then back up. This usually results in a complete understanding of at least one feature of the system, and sometimes gives insight into other parts of the system as well.
Once I understand what functions are being called and what stored procedures, tables, and views are involved, I then do a search through the code to find out what other parts of the application rely on these same functions/procs. This is how I find out if a change I'm going to make will break anything else in the system.
It can also sometimes be useful to attempt to make diagrams of the database and/or code structure, but sometimes it's just so bad or so insanely complex that it's better to ignore the system as a whole and just focus on the part that you need to change.

My big problem is that I (currently) have very large systems to understand in a fairly short space of time (I pity contract developers on this point) and don't have a lot of experience doing this (having previously been fortunate enough to be the one designing from the ground up.)
One method I use is to try to understand the meaning of the naming of variables, methods, classes, etc. This is useful because it (hopefully increasingly) embeds a high-level view of a train of thought from an atomic level.
I say this because typically developers will name their elements (with what they believe are) meaningfully and providing insight into their intended function. This is flawed, admittedly, if the developer has a defective understanding of their program, the terminology or (often the case, imho) is trying to sound clever. How many developers have seen keywords or class names and only then looked up the term in the dictionary, for the first time?

It's all about the standards and coding rules your company is using.
if everyone codes in different style, then it's hard to maintain other programmer code and etc, if you decide what standard you'll use have some rules, everything will be fine :) Note: that you don't have to make a lot of rules, because people should have possibility to code in style they like, otherwise you can be very surprised.