I need to implement cover flow in our iphone app. Our app need to display images from server. We already have webservice to return list of pictures. Number of pictures will grow over time to 1000s of pictures.
Here I need your help to decide which library is good for my situation without any memory issues. and any experiences you have in similar scenario.
I appreciate any input you can give in my scenario
Here is list of libraries in mind.
tapkul
OpenFlow
FlowCover
Please help deciding which library to use and
I can't help on the issue of which library is best to use, but be aware apps have been rejected in the past for doing including cover-flow like features.
If you really must include cover-flow functionality, I'd recommend you write a little test app with each of the available libraries and see which fits your requirements the best. You might also try memory profiling the different solutions and see which consumes the least resources.
There probably isn't a "one size fits all" answer to this question, as everyone's requirements will be slightly different.
Related
I need to develop a client application for a site that host and show images.
The client should shows all new images and take a picture and send to website.
I'm a newbie to iOS programming so this question:
In an application alike this, there's the need to create a Model? I ask this question because I think I can do anything with Controllers but maybe I'm wrong.
While there is never a "need" to create a model, it's good form to do so, and it'll likely save you many headaches down the road. Ultimately, you're going to need to deal with images and websites and how they interact with each other and whatnot, so you might as well do it in models from the outset.
I'm as guilty as anyone for wanting to see immediate results and hack together something quickly, but I always regret it later on, and have to spend more time than I'd expected refactoring it into something usable.
The MVC pattern as used in Mac OS and iOS applications isn't something best explained in an answer box but here's a link to some simple documentation about the roles of Models, Views and Controllers
Some good basic introductions to start with, which also have relevant links to the next stage of documentation are:
Cocoa Core Competencies
Cocoa Application Competencies for iOS
Read these excellent articles first. You'll learn better and faster if you do some basic reading.
What resources can you recommend for learning how to architect a iPhone application?
Background of the question is that most of the resources explain the usage of a single class or concept (and i appreciate that a lot to learn something about the specific topic) but as far as i can see they lack unfortunately to describe how to put things together for typical real world applications.
This won't give you a ton of help with architecting large applications, but I found this site to be really useful for finding good examples for working with animations and all the ViewController stuff: http://appsamuck.com/
You should focus your search on best practices, as a lot of the details that go behind proper architecture are found in getting those general fundamentals right.
Otherwise, if you want to know how "typical real world applications" are designed, you should go and find some open source projects and download them. There will undoubtedly be a variation in quality but it should give you a general idea of how apps get built.
Overall I don't think you'll see a general tutorial on how to build an iPhone app because all applications are different. They solve different problems under different requirements for different kinds of users. You'll probably find that the answer to your question can only be found by trying to build something on your own.
How do you design a UI like Facebook?
Is it hard to implement a custom skin into a iphone app? How is it done?
Do I need to follow apple's guideline? What if I don't want to?
How do you design a UI like Facebook?
Facebook's iPhone app appears to be built around using UITableView in various guises. It looks like it adheres to the Apple Human Interface Guidelines.
Is it hard to implement a custom skin
into a iphone app? How is it done?
Skins are just graphic elements that are designed to have their image components swapped out. They are not difficult to implement.
Do I need to follow apple's guideline?
What if I dont want to?
Apple will not penalize you for a non-standard interface. The only interface restrictions are (1) some issues of obscene content and (2) you can't create the illusion that the device itself is broken, has crashed or otherwise failed.
A bit of advice. Don't use non-standard interfaces.
Good interfaces are almost by definition standardized so that users don't have to think about them. Novel interfaces slow users down even if they have no problems otherwise. Just try switching rapidly between Mac, Windows and Linux sometimes. None of the interfaces has major problems per se but having to stop and think how to do something in each particular interface is a pain. You can create the same problem by using a good but non-standard interface within an app.
That is assuming of course that you can actually create a good interface. There are far, far more ways to make bad interfaces than there are to make good ones. Most interfaces fail even those designed by interface gods. The standardized interfaces are the result of tens of thousands of hours of testing and years of experience. You're unlikely to whip out something really new and useful your first time out.
If you try something novel I suggest you mock it up first and then test let people test it without giving them any instruction. You'd be surprised how complex it can get. We used to just make photoshop mockups and then ask test users what they thought each element did or which element they would choose to accomplish a particular task. We were surprised at how poorly our (the developers) perception of the interface overlapped with the perception of the users.
In sum, a novel interface is more likely to hurt your app than help it.
With regard to how to build an app like Facebook, check out Three20. In particular, the TTLauncherView is the class that implements the Springboard-like grid of icons.
3- You don't need to follow the AHIG. But be careful if you don't, because it's very easy to go wrong doing so. Users like to not have to learn anything new. They know the typical Apple software UI, so if you use it, users will know how to use your app as soon as they buy it. If you don't use it, it is important to make sure that the UI is exceedingly easy and intuitive, and looks good to an iPhone user's eyes (and fingers).
Are there any guidelines on pitfalls to avoid while developing iPhone applications?
Sure, thousands. The same is true for any software development. Unfortunately, the easiest way to enumerate them is to write them down on a sheet of paper while waiting for a friendly soul to release you from the one you just fell into.
However:
Don't try to reinvent the wheel. The iPhone API is very complete -- you just have to LOOK for the facility you need. Things are NOT always implemented the way you would expect. Read the guides, carefully. Look at the tutorials and analyze how they work. (Try changing a line here or there in the tutorial to see what difference the change makes.) The single biggest mistake I have made in 1 year of iPhone development is not trying hard enough to find the iPhone way of doing something.
Don't ignore memory management; master it early and often. Use the Object Allocation and Leaks tools in Instruments to check for memory leaks frequently. I'd recommend checking after you complete each feature or view; more often than that if you keep finding bugs. Eventually you may understand it so well you can stop doing this.
Don't just use the default build settings. Play around with them to understand what they do. Figure out certification and distribution. GET INTO THE DEVELOPER PROGRAM QUICKLY -- it can take a while to push through that pipeline. [ AND when you get that notification that you need to renew, get it on instantly -- there have been problems with that process. ]
Don't neglect to read the Human Interface Guidelines (HIG) carefully. If they say not to do something -- DON'T DO IT. Apple will reject applications that misuse their iconography.
Don't stint on marketing. Yes, the App Store puts your app in front of millions of people... In theory. But the odds of getting front-paged are slim. There are a lot of great apps on the App Store that haven't sold much because no one knows about them.
Don't rest on your laurels. If a new technology comes out, find out if it makes your job easier; if it does, take the time to learn it. Personal example: I'm just now trying to switch from SQLite-based data management to Core Data, because I was in a hurry at the time I started my most recent project; now I wish I had slowed down and thought about it.
Don't go into your design thinking (for example) "How do I implement my concept with a table view?" It's true that table views are natural for many informational and utility applications, but don't be constrained. Instead, think about what users will want to be able to do, how you can make it easier for them -- put things together that will be used together, etc. If you've never explored the concept of Use Cases, read up on them.
Don't hesitate to build composite views. Many of the questions I have seen here on Stack Overflow have to do with putting a toolbar at the top of a table, or having an image in the background of a text field. I understand the desire to do things the easy way, and as I state in #1 above, if there is an easy way, use it. But in many cases the solution is just to layer a couple of views with appropriate placement and transparency.
Think about what might be Apple-approved from the start.
App Rejected is one of several useful sites to help understand Apple's mostly undocumented standards. (One more.) (A previous question on app store rejection reasons.)
A few quick examples:
Using a UIWebView can get your app a 17+ rating.
Coding with an undocumented/private API = rejected
Version number < 1.0 might= rejected
Not enough feedback about network success/fail = rejected
Too much network use = rejected
Clearly limited free version vs full version = rejected
The word 'iPhone' in the app name = rejected
The above links contain many more examples, and more details about those examples.
Don't neglect the programming guides. While the documentation is quite extensive, the programming guides contains a veritable trove of useful tips and "insider" information that simply cannot be gleaned from reading method definitions. I spend just as much time reading the guides for a technology (say, Core Data) as I do actually implementing it.
Don't assume you know what a method does. If you have any degree of doubt about the functionality of a method, it is well worth your time to go look it up in the documentation to verify.
Wonderful examples from #Amagrammer above.
I would love to add that the first place to start is iPhone development is Photoshop. This is still the best advice I can give to anyone who is starting out. I now use OmniGraffle because it has awesome stencil templates.
What I find is that even for super simple app's, draw up your prototype and look for usability issues and work flow issues. It is 100x quicker to redraw your app than re-code it. I have fallen into this trap numerous times and now actually draw up some pretty simple functionality to see what it will look and feel like.
This advice will save you 10s maybe even 100s of hours in hopefully getting your app right first time and getting you to think through what the issues are. Throwing away code sucks and I have done it not because the code was bad but because it made the usability or solution worse. I think the best of us end up throwing code away and prototyping your design definitely will help in having to RTFM for something you did not have to build in the first place.
If you don't have an great designer, and can't do great design by yourself, then don't even start iPhone app development. This rule only applies if you want/need to make money with your apps.
I'm at a point in my freelance career where I've developed several web applications for small to medium sized businesses that support things such as project management, booking/reservations, and email management.
I like the work but find that eventually my applications get to a point where the overhear for maintenance is very high. I look back at code I wrote 6 months ago and find I have to spend a while just relearning how I originally coded it before I can make a fix or feature additions. I do try to practice using frameworks (I've used Zend Framework before, and am considering Django for my next project)
What techniques or strategies do you use to plan out an application that is capable of handling a lot of users without breaking and still keeping the code clean enough to maintain easily?
If anyone has any books or articles they could recommend, that would be greatly appreciated as well.
Although there are certainly good articles on that topic, none of them is a substitute of real-world experience.
Maintainability is nothing you can plan straight ahead, except on very small projects. It is something you need to take care of during the whole project. In fact, creating loads of classes and infrastructure code in advance can produce code which is even harder to understand than naive spaghetti code.
So my advise is to clean up your existing projects, by continuously refactoring them. Look at the parts which were a pain to change, and strive for simpler solutions that are easier to understand and to adjust. If the code is even too bad for that, consider rewriting it from scratch.
Don't start new projects and expect them to succeed, just because your read some more articles or used a new framework. Instead, identify the failures of your existing projects and fix their specific problems. Whenever you need to change your code, ask yourself how to restructure it to support similar changes in the future. This is what you need to do anyway, because there will be similar changes in the future.
By doing those refactorings you'll stumble across various specific questions you can ask and read articles about. That way you'll learn more than by just asking general questions and reading general articles about maintenance and frameworks.
Start cleaning up your code today. Don't defer it to your future projects.
(The same is true for documentation. Everyone's first docs were very bad. After several months they turn out to be too verbose and filled with unimportant stuff. So complement the documentation with solutions to the problems you really had, because chances are good that next year you'll be confronted with a similar problem. Those experiences will improve your writing style more than any "how to write good" style guide.)
I'd honestly recommend looking at Martin Fowlers Patterns of Enterprise Application Architecture. It discusses a lot of ways to make your application more organized and maintainable. In addition, I would recommend using unit testing to give you better comprehension of your code. Kent Beck's book on Test Driven Development is a great resource for learning how to address change to your code through unit tests.
To improve the maintainability you could:
If you are the sole developer then adopt a coding style and stick to it. That will give you confidence later when navigating through your own code about things you could have possibly done and the things that you absolutely wouldn't. Being confident where to look and what to look for and what not to look for will save you a lot of time.
Always take time to bring documentation up to date. Include the task into development plan; include that time into the plan as part any of change or new feature.
Keep documentation balanced: some high level diagrams, meaningful comments. Best comments tell that cannot be read from the code itself. Like business reasons or "whys" behind certain chunks of code.
Include into the plan the effort to keep code structure, folder names, namespaces, object, variable and routine names up to date and reflective of what they actually do. This will go a long way in improving maintainability. Always call a spade "spade". Avoid large chunks of code, structure it by means available within your language of choice, give chunks meaningful names.
Low coupling and high coherency. Make sure you up to date with techniques of achieving these: design by contract, dependency injection, aspects, design patterns etc.
From task management point of view you should estimate more time and charge higher rate for non-continuous pieces of work. Do not hesitate to make customer aware that you need extra time to do small non-continuous changes spread over time as opposed to bigger continuous projects and ongoing maintenance since the administration and analysis overhead is greater (you need to manage and analyse each change including impact on the existing system separately). One benefit your customer is going to get is greater life expectancy of the system. The other is accurate documentation that will preserve their option to seek someone else's help should they decide to do so. Both protect customer investment and are strong selling points.
Use source control if you don't do that already
Keep a detailed log of everything done for the customer plus any important communication (a simple computer or paper based CMS). Refresh your memory before each assignment.
Keep a log of issues left open, ideas, suggestions per customer; again refresh your memory before beginning an assignment.
Plan ahead how the post-implementation support is going to be conducted, discuss with the customer. Make your systems are easy to maintain. Plan for parameterisation, monitoring tools, in-build sanity checks. Sell post-implementation support to customer as part of the initial contract.
Expand by hiring, even if you need someone just to provide that post-implementation support, do the admin bits.
Recommended reading:
"Code Complete" by Steve Mcconnell
Anything on design patterns are included into the list of recommended reading.
The most important advice I can give having helped grow an old web application into an extremely high available, high demand web application is to encapsulate everything. - in particular
Use good MVC principles and frameworks to separate your view layer from your business logic and data model.
Use a robust persistance layer to not couple your business logic to your data model
Plan for statelessness and asynchronous behaviour.
Here is an excellent article on how eBay tackles these problems
http://www.infoq.com/articles/ebay-scalability-best-practices
Use a framework / MVC system. The more organised and centralized your code is the better.
Try using Memcache. PHP has a built in extension for it, it takes about ten minutes to set up and another twenty to put in your application. You can cache whatever you want to it - I cache all my database records in it - for every application. It does wanders.
I would recommend using a source control system such as Subversion if you aren't already.
You should consider maybe using SharePoint. It's an environment that is already designed to do all you have mentioned, and has many other features you maybe haven't thought about (but maybe you will need in the future :-) )
Here's some information from the official site.
There are 2 different SharePoint environments you can use: Windows Sharepoint Services (WSS) or Microsoft Office Sharepoint Server (MOSS). WSS is free and ships with Windows Server 2003, while MOSS isn't free, but has much more features and covers almost all you enterprise's needs.