There are tons of resources concerning coding on the iPhone. Most of them concern "how do I do X", e.g. "setup a navigation controller", or "download text from a URL". All good and fine.
What I'm more interested in now are the questions that follow the simpler stuff - how to best structure your complex UI, or your app, or the common problems that arise. To illustrate: a book like "Beginning iPhone 3 Development" tells you how to set up a multi viewcontroller app with an top 'switcher' viewcontroller that switches between views owned by other view controllers. Fine, but you're only told how to do that, and nothing about the problems that can follow: for example, if I use their paradigm to switch to a UINavigationViewController, the Navigation bar ends up too low on the screen, because UINavigationViewController expects to be the topmost UIViewController (apparently). Also, delegate methods (e.g. relating to orientation changes) go to the top switcher view controller, not the actual controller responsible for the current view. I have fixes for these things but they feel like hacks which makes me unhappy and makes me feel like I'm missing something.
One productive thing might be to look at some open source iPhone projects (see this question). But aside from that?
Update
To clarify: I suppose what I'm asking about could be summarised as "Recipes and Gotchas for iPhone development". The sort of things that are of interest to developers, but aren't covered in any of the iPhone books etc. that I've seen, such as:
I'm writing an iPad app and want a UISplitViewController presented to the user only some of the time, which Apple seem to be saying I can't do. Is it possible? How?
Apple don't give me a way to stylise my app in a convenient, across the board way (e.g. font tweaks, or colours). How can I approach styling my app?
Memory management isn't made any easier by some of the inconsistencies in UIViewController method names (e.g. viewDidUnload is not the opposite of viewDidLoad, despite the name). Is there a consistent easy way to tidy that up and make view controller memory management less error prone?
How can I consistently and easily test my view controllers for behaving correctly when a memory warning comes in? It's easy to simulate a memory warning in the Simulator, but if the UI I want to test is showing (and is a 'leaf level' view controller), it won't get its view unloaded because it is currently visible.
N.B. I'm not actually asking the above questions here -- I think I have decent answers to them! -- just giving examples of 'good' questions that illustrate this stackoverflow question.
The WWDC talks available on iTunes U (at http://developer.apple.com/videos/wwdc/2010/) have some great information about structuring, especially in the Application Frameworks section.
If you're talking about code, use the Model/View/Controller pattern like in most Web applications:
The model code defines the objects that your program represents. A time tracker app, for example, might have model objects like Task, TimeSlice, and User (especially in a network setting).
The view code is provided for "free" with the iOS SDK, unless you need specialised view code. These are UIImageView, UIButton, etc.
The controller code bridges the 'gap' between the model and view. The controller will change the views to reflect the model selected by the user and facilitate the selection of model objects.
This is the base design pattern for any iPhone app, and it's the one that most will use.
If, on the other hand, you refer to what we in my company call UX (user experience) design, however, you can't beat the Apple HIG guidelines in the Apple iOS SDK documentation set, available online or in Xcode from the Help menu.
The other thing I recommend quite highly is to play around with some test/dummy code. Nothing can top experience. Experimenting with the iOS SDK and getting your hands dirty will allow you to truly learn the best ways to design apps.
Edit:
Also, delegate methods (e.g. relating to orientation changes) go to the top switcher view controller, not the actual controller responsible for the current view.
Can you clarify? In all of the apps I've written, the currently shown view controller receives the orientation change methods. Note that there are two methods. shouldAutorotateToInterfaceOrientation: allows you to decide if the view should rotate, and didRotateFromInterfaceOrientation: allows you to re-layout the view if necessary.
Please go through this link. In this they have explained clearly about design patterns.
http://www.raywenderlich.com/46988/ios-design-patterns
You might want to consider watching videos like the CS193p course from Stanford on iTunes U. They go through the most important parts of iOS development in deep, and give some source code.
As far as I can tell, there isn't a book or resource which deals with the sort of advanced gotchas and recipes that I was looking for. Loads of useful resources exist, but just not addressing the stuff I'm thinking about.
Related
I have a question about universal app. My app will not have storyboards or xib file. There is possibility to write universal iPhone/iPad application without it? I found some tutorial how to create universal app with storyboard, but i don't want (i can't) use this feature in my project.
If it is possible What should i do? If i have to made changes only in ViewControllers? I'm start to do this, i'm not changing old project so i can do anythng - what should i learn/what should i remember?
I'm targeting to iOS 5.
EDIT:
I have a screen information in resource file and my rootViewController or any other ViewController will be created in compile time, so i can't have xib file for that, i can't put button on xib with Interface Builder becouse i don't even know how many buttons i will have there. I don't know how many screens i've got till i hit run in my project.
Not only can you write any type of iOS app without Interface Builder, it is actually much more testable and pliable. Some auto layout tricks are difficult (not possible?) in IB style projects, as well.
There is an incredibly impressive library called Masonry that wraps the NSLayoutContraint syntax. This makes it quite pleasurable to subclass views while not having to use ugly VFL or incredibly verbose NSLayoutContraint syntax (not even going to address frame setting...blech!). IB style apps also promote bad software development practices and anti-patterns (just dumping everything in a view controller presentation-wise. No Separation of Concerns!). Also, it is more difficult to work on larger teams (IMHO even small teams) while utilizing Nibs, Xibs, and Storyboards due to merge issues.
On top of all of that, you gain a much deeper understanding of the classes you are working with (UIView, UIResponder, etc.) when writing code in this manner (once again IMHO). There is an interesting article outlining some of these issues in more detail: http://doing-it-wrong.mikeweller.com/2013/06/ios-app-architecture-and-tdd-1.html This is by no means the only article that discusses this problem. Also, this will help for your app delegate: creating a universal window-based iphone app without generated xib file
This is certainly possible, I have only used storyborads once in the many apps I have published. As for not using XIBs, I am not sure why you would want to do that. You can lay out your views at runtime in the init method, but I feel like that is just making things unduly hard on yourself. You can set a XIB up for the iPad and one for the iPhone so you can tailor the UI specifically to each device.
Perhaps if you go into a bit more detail about why you are imposing this requirement on yourself we can discuss if it si worth the effort to go down that road.
Good Luck.
I'm new to iphone development. There's a lot of books on this topic available. But most of the beginner's guides are mostly concerned with Interface Builder usage and lack the information about existing built in XCode code templates or something that could help me in understanding MVC implementation in code. I found that it is possible to write working iOS program without ViewController at all. Well, it seems to me like that after working with the sample code called ViewTransitions.
So, the question is - why is that possible to avoid ViewController implementation in a program that has an interface with a button? If the answer is going to be too long, could you please recommend kind of tutorial or manual covering this topic.
Thanks in advance.
#user697562's answer is essentially correct: in the case of ViewTransitions, the role of the controller is played by the app delegate. The app does next to nothing -- it just switches betweeen two views to demonstrate several possible transition effects -- so a UIViewController isn't really needed there.
Notice that there's also nothing in ViewTransitions that you could really call a model object. If you're looking for a strong example of MVC, ViewTransitions isn't the best project to look at. Other sample projects, such as TheElements, give a better demonstration of MVC in action.
There is a concept called delegation. A concept which helps maintain MVC. It helps to keep the model separate from controllers. For eg: - UITableView/UICollectionView , which knows how to display the data and other ui stuff.
But it does not know which cell to display or what data to display at a particular index. And this is where delegation and the delegate object comes into place. UICollectionView handles all the view part whereas all the non view part is handled by the delgate object, which gives the required data for the view. This way a delegate(usually a separate view controller) acts as a data source and UICollectionView as a ui renderer.
in ViewTransitions, there IS an App Delegate, which is kind of your sole "controller". Even ViewTransitions has:
transition.delegate = self;
IOS is a bit different from some frameworks in that you aren't as "in control" of what is going on. It often uses a delegation model where you set your code as the delegate, but it (IOS) is in control. Still, you can write in MVC style, it's just your "C" isn't fully in charge.
For my job, I've been writing an iPad application that the user can enter data into, view some pictures, etc. It's been annoying me that I'm reaaaallly slow at writing in Obj-C and I find myself bogged down in the UI (an example would be I always have to put in a UITableView which is time consuming...) I think that I have a pretty good handle on the language and Apple SDK.
Does anyone have any tips regarding how to speed up the development process from a UI perspective? Are there alternative tools to xCode and IB? Are there libraries with classes that are faster to program w/? Anything is appreciated,
mj
Interface Builder can already speed up your development considerably if you learn to use it. For example, see this custom table cell with IB tutorial.
For example, at my current employer I've seen a Cocoa Mac OS X app where the settings dialog was done completely in IB... there was no code for modifying or sync'ing the values in the NSUserDefaults with the interface elements, everything was done in IB.
Also, see this interesting article: Striking the Balance: Interface Builder vs. Code.
Avoid UITableViewController if you aren't already.
For speeding up TableView dev, I always keep a pretty generic implementation of TableView handy that I can copy and paste snippets from.
If you are constantly doing TableViews for different object types, try using Protocols to make the implementations more uniform.
Don't be afraid of UIViews as subviews as opposed to constantly using UIViewControllers. Sometimes a VC is just an extra layer of complexity that you don't need.
My experience is that the biggest thing you can do as an iPhone developer to become more efficient is to know when and when not to use Controllers as opposed to Views when doing complex interfaces.
Wish I could be more specific but your question is a little vague... there's nothing wrong with Interface Builder, it's just a steep learning curve.
This is Cocoa Touch (et al), iPhone, XCode only.
After completing my first commercial iPhone app, I'm struggling a bit to find a way to start and expand an app from scratch which gives the most linear development (i.e., the least scrapping, re-write or re-organization of code, classes and resources) as app specs change and I learn more (mostly about what Cocoa Touch and other classes and components are designed to be capable of and the limitation of their customization).
So. File, New Project. Blank window based app? Create the controllers I need, with .xib if necessary, so I can localize them and do changes requested by the customer in IB? And then always subclass each class except those extremely unlikely to be customized? (I mean framework classes such as UIButton, CLLocation etc here.)
The question is a generic 'approach' type question, so I'll be happy to listen to handy dev practices you've found paid off. Do you have any tips for which 're-usable components' you've found have become very useful in subsequent projects?
Clients often describe programs in terms of 'first, this screen appears, and then you can click this button and on the new screen you can select... (and so on)' terms. Are there any good guides to go from there to vital early-stage app construction choices, i.e. 'functions-features-visuals description to open-ended-app-architecture'?
For example, in my app I went from NavBar, to Toolbar with items, to Toolbar with two custom subviews in order to accommodate the functions-features-visuals description. Maybe you have also done such a thing and have some advice to offer?
I'm also looking for open-ended approaches to sharing large ("loaded data") objects, or even simple booleans, between controllers and invoking methods in another controller, specifically starting processes such as animation and loading (example: trigger a load from a URL in the second tab viewcontroller after making sure an animation has been started in the first tab viewcontroller), as these two features apply to the app architecture building approach you advocate.
Any handy pointers appreciated. Thanks guys.
Closing this up as there's no single correct answer and was more suitable for the other forum, had I known it existed when I asked :)
If you want to know the method I ended up with, it's basically this:
Window-based blank app
Navigation Controller controls all, whether I need to or not (hide when not used)
Tab Bar Controller if necessary
Connect everything <-- unhelpful, I know.
Set up and check autorotation, it might get added to some view later.
Add one viewcontroller with xib for each view, you never know when they want an extra button somewhere. It's easier to copy code than make the max ultra superdynamic adjustable tableviewcontroller that does all list-navigation, etc.
Re-use a viewcontroller only when just the content differs in it, such as a detail viewcontroller.
Minimize code in each viewcontroller by writing functions and methods and shove them in a shared .m
Everything that's shared ends up in the App delegate, except subclassed stuff.
Modal viewcontrollers are always dynamically created and never have an xib.
I am primarily a web developer (ruby, python) that is new to iPhone development. I've done some desktop development in the past within the MS environment (C#), but never anything on the mac.
I'm trying to build a really simple iPhone application and I am confused by the way that views work in general. If someone can provide advice for my particular problem, along with some resources where I can learn how to architect iPhone views in the future, that would be awesome. I feel like a lot of the Apple documentation that I've come across is too specific - I am lacking a fundamental understanding of how views work on the iPhone.
My particular problem looks like this:
I need one view that displays some downloaded text content. This is the view that shows when the app loads, and it is pretty straightforward.
Then I need a settings area (I've already decided I don't want to use the iPhone settings area). The settings area main page will have some text fields on it. It will also have a 2-row grouped table. Each cell in that table will take you to another view which also has a grouped table used for multi-select. I suspect that I can reuse the same view for these two final "detailed setting" views.
In summary:
home page
settings main page
detailed setting 1
detailed setting 2
Any help and advice appreciated.
It sounds like you already have a good idea of what you want each of your screens to look like; that's a good place to start.
What you're probably going to want to do is use Interface Builder to lay out the objects in each view (textfields, buttons, etc.), and then have a custom View Controller (subclass of UIViewController) for each view. You would then navigate to a new view by doing something like:
MySettingsController *controller = [[MySettingsController alloc]
initWithNibName:#"SettingsView" bundle:nil];
[[self navigationController] pushViewController:controller animated:YES];
(assuming a navigation-based app).
If you haven't yet, I recommend reading Apple's View Controller Programming Guide
Some advice: Despite your back ground, don't think of the views as pages or the app as a web site. That will cause you problem in your design because the technology is different and views don't work like web pages and apps don't work like web sites.
The major difference is that while web pages often contain actual data, views do not. The view object is only concerned with display. It doesn't know what it is displaying and it doesn't store or logically manipulate the data. The data comes into the view from the view controller which itself gets it from the data model.
See Cocoa Core Competencies: Modal View Controller
Rails uses MVC if you've used that with Ruby. The basic principles are the same.
Well, there are plenty of information on Apple developers' pages: you could start reading Your first iPhone application
There are quite a few good sites with very good info both on cocoa and iPhone developing:
Cocoa with love
iCode blog
and many more (google is your friend in this).
A couple of books I liked are "Beginning iPhone3 Development" and "iPhone developer cookbook".
The first is probably more useful at the beginning (no pun intended)
As for the specific case of yuor application, you could use a navigation controller for the settings page, and each time you need to dive into the details you will just push the right view onto the navigation controller's view stack.
So you would design 4 views with the interface builder
Main view
Settings view
Detail 1
Detail 2
And then push the views onto the navigation controller.
It's pretty straightforward, I won't go into the details, but just searching something like "iphone navigation controller example" on google will give you plenty of samples that you can easily adapt to your needs.
These were all helpful responses, in particular the reference to the iPhone View Programming Guide. This helped me to diagnose my misunderstanding which was related to the role of View Controllers, and the relationship between individual views and view controllers. I think part of my confusion came from learning MVC in the context of Rails, where this relationship is quite different.
For others looking for advice in this general area, I would recommend checking out Lecture 6 from Stanford's iTunes U iPhone Application Development course from Winter 2010 "Designing iPhone Applications, Model-View-Controller, View Controllers", and the lectures 5 & 7 if you have time. I think that was when the penny dropped for me, despite having already looked at a few of the books mentioned here.