How to trigger a WiFi connection on iPhone SDK 4.1 - iphone

Sometimes the iOS device will not connect to the available WiFi automatically, but it will if Safari is launched and try to browse to any site (or go to Settings->Wi-Fi and select the desired network). This is probably for battery savings reasons.
How to trigger this from your app?

The higher level Cocoa Touch network APIs will attempt to turn on the radios if needed. Until then they are kept off as much as possible to conserve battery power (after certain time-outs).
Safari probably uses one of the high level HTTP APIs for browsing.

You can try something like <key>UIRequiredDeviceCapabilities</key><array><string>wifi</string></array> in Info.plist. It actually means "persistent wifi" (i.e. keep Wi-Fi up even when the display is asleep), but it might also trigger a reconnection.
EDIT: Alternatively, <key>UIRequiredDeviceCapabilities</key><dict><key>wifi</key><true/></dict>. There's also <key>UIRequiresPersistentWiFi</key><true/> which does something slightly different.

Related

UIRequiresPersistentWiFi equivalent for cellular connection

OK, so I specified a UIRequiresPersistentWiFi key of my App's plist to YES so the iOS won't stop fetching the data when my app is in the background.
However, when the user uses cellular connection (not wifi) and my app is in the background, the download of the data is stopped after several minutes.
I double checked the docs and it seems there is no equivalent of UIRequiresPersistentWiFi for cellular network that I could set.
Is there any way I can make the connections over cellular network survive while the app is in the background? Any hints?
Cheers!
Updates:
I am making an Internet radio app. Stream is combined with mp3s which I request one after another (can't request them in advance, can't change server side). It works when my app is in the background and uses wifi. However, when using cellular connection the network requests are not performed after some time spent in the background. There is no place for changing the strategy. The app is in the AppStore and it had worked before. I guess they changed something in the new version of the system.
What is more I do not need throttling. My radio app has been already approved and is in the AppStore. The stream is sent with 128kb/s (that is the maximum) so that is not a problem. It looks like system silences my network requests (when on cellular network) after some time in the background. However, this only happens when I try to start the connection in the background.
Description:
App is in the background playing a mp3 streamed over cellular
network.
Mp3 ends
I request the URL to another mp3
The request is not performed*.
*works when using WiFi.
I'm fairly certain there isn't something like this for Cell networks. Here is my reasoning:
Cell service costs money. A LOT of money. Per minute. Wifi service does not cost money, in comparison.
AT&T does not have very much bandwidth, and charges users extra for extra bandwidth usage.
Apple is a company that wants to make the user experience as clean and nice as possible.
When costs are exorbitant through no fault of their own, users are angry and their experience is not nice.
If Apple lets you have a constant connection to the web outside of wifi range, the user's cost of service would skyrocket and they wouldn't know why. And if Apple gives programmers this ability, somebody would abuse it. So, I'm sure that Apple won't allow you to do that.
Why do you need a constant internet connection when your app is in the background anyway (unless, I guess, you're making an internet radio app)? Keep in mind that, when in the background, your app can be terminated without warning at any time. You may want to rethink your strategy if you can't find a way to do this. :/
I think there is no equivalent of UIRequiresPersistentWiFi, there reasons probably include the ones pointed out by Tusting2121.
But please note that UIRequiresPersistentWiFi is connected with energy saving. The wifi module consumes energy, so normally it is shut down after some time to save some energy unless UIRequiresPersistentWiFi is set.
Such enrgy saving, I believe, is not a case in cellular case.
And the fact that your connection disappears after certain minutes in cellular mode may be caused by something completely different that the copy of wifi energy saving mechanism you claim. See for example this article which suggests that you are obliged to throttle your 3G data flow.
Add audio to your UIBackgroundModes entry in Info.plist.
According to the Apple Docs: In your callbacks, though, you should do only the work necessary to provide data for playback. For example, a streaming audio app would need to download the music stream data from its server and push the current audio samples out for playback. You should not perform any extraneous tasks that are unrelated to playback.
You may also get some value out of the voip entry - you can setKeepAliveTimeout:handler: to have your handler called on a periodic basis to populate your data stream.

Find if 3G is enabled in iphone settings

is it possible to find whether 3G or Edge is enabled in the phone setting through applications?
Its not possible to read the private Settings data (since apps generally can't access data that is not thier own), so I don't think this is possible. However, you can use the [Reachability]
(http://developer.apple.com/library/ios/#samplecode/Reachability/Introduction/Intro.html) code from Apple. Also, you can try going through NSUserDefaults.

iPhone alert an alarm if stolen

We are developing an enterprise application .The phones are connected to a Wifi router. The objective is to trigger an alarm if the phone moves out of the secure area .. (outside the building)
What is the best way to check if the iPhone is always inside the building .
some of the options we tried are
1.using Wifi(continous ping to wifi network),if not trigger an alarm .
2.if coordinates change (using GPS)
Are there any other means to achieve this .
You can use Location Services in iOS 4 (with the background location feature) to determine when the phone has moved to a different location.
#indragie's idea of using Location Services is a good one. If you can be sure that the WIFI SID isn't going to change, you could probe to see which access point the iPhone is currently associated to. If you are going to ping, then a better approach is to make the system service agnostic, and simply issue an HTTP query on a regular basis to your enterprise server. The server can then have a policy language on it declaring acceptable access points (from a variety of metrics). This might be set up to allow people to take their iPhones home.
Your best bet is GPS as the phone will not be able to find its location if you rely on WiFi and the device is not connected to a WiFi network.
Check out Apple's documentation for Location Awareness capabilities here http://developer.apple.com/library/ios/#documentation/UserExperience/Conceptual/LocationAwarenessPG/CoreLocation/CoreLocation.html
You will be able to track "significant" or standard location changes in the background, details can be found here http://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html#//apple_ref/doc/uid/TP40007072-CH5
[edit to include]
This might be of interest to you too - http://longweekendmobile.com/2010/07/22/iphone-background-gps-accurate-to-500-meters-not-enough-for-foot-traffic/
It depends on what you want to do. Just to let the iPhone user know that he/she is moving away, using Location Services is good enough.
However, if you want to have a server that makes sure all the devices are within range, then it's more complex because your application may get suspended without a notice from a background state; in other words, you may not be able to catch the moment when your application terminates and take appropriate actions. Therefore you are going to need a heartbeat system like pinging to the server in this case.

What does iPhone OS 3.0 need from a programming perspective?

iPhone OS 3.0 is being announced and previewed next week (March 17).
We all know the feature set users want. Copy/paste, MMS, Flash on iPhone, etc.
We'll see about those.
What I'm interested in what does the development community feel the SDK is missing, in need of, to make programming for the platform easier and more productive.
A more complete Interface Builder with support for custom palettes and all sorts of goodies like that.
Better control over the keyboard.
Better unit testing support. (Unit testing can be done, but only on the simulator, and it's very awkward to set up.)
Push notifications. Please.
A more accurate simulator, i.e. one with a more accurate set of frameworks.
The ability to easily build views like the Mail compose window.
For that matter, an in-application compose window.
A better way for apps to share data locally than by invoking URLs.
Access to the calendar, notes, mail (possibly read-only), and bookmarks (again, read-only) databases. Maybe even limited access to the iPod database—even just the ability to read song metadata and access and change the playing song would be helpful.
Some sort of middle ground between UILabel and UIWebView that allows for formatted text without a huge hassle.
More built-in toolbar icons.
The return of the "glass" button style that was in the beta SDK.
A few useful internal views, like UIProgressHUD, exposed.
And last but not least...
A pony.
An easy Javascript bookmarklet installation method for Mobile Safari. (OpenRadar: 1, 2)
UIWebView needs more of UIScrollView's properties and methods, such as contentOffset.
More configurability on some of the built-in behaviors and views, e.g. the button text on UITableViewCell's "Delete" button, or the styles and text of UIAlertSheet/UIAlertView buttons. (Some of these can be done today with undocumented calls, but I'd rather not rely on those.)
More flexibility from UINavigationController, such as the ability to push/pop views that selectively don't display the navigation bar but using the same animations and stack, or more customizability over the navigation bar button labels and behaviors.
The ability to restrict interface orientation per UIViewController, not just accept/reject changes via shouldAutorotate. E.g. I want my main content view to be autorotatable, but I want my navigation hierarchy and settings screens to always display in portrait, even if the content view was rotated to landscape.
libxml and its handy DOM XML parser instead of the SAX-based NSXMLParser.
libcurl w/SSL, or more options and functionality for NSURLConnection.
Ability to check whether a URL scheme is registered. This could be used for apps to detect whether other specific apps are installed, and enable functionality selectively, e.g. when Instapaper detects Tweetie is installed, it can offer a "Post with Tweetie" button. (Disclaimer: That was a plug. I make Instapaper.)
I'm sure I'll think of more, but overall, I'm very happy developing for the iPhone. I'm amazed at the quality and sophistication of the iPhone OS, the SDK, and the development tools given how incredibly young they all are.
I'm surprised no one has mentioned garbage collection yet. Objective-C 2.0 on the Mac supports optional garbage collection. I don't really see any reason it wouldn't work just fine on the iPhone as well and it would eliminate much of the tedium of having to explicitly release objects all over the place.
What I'm hoping most for is to allow iPhones to talk to each other either via Bluetooth or some other means. Granted, they can talk via Bonjour if they are on the same Wi-Fi network, but that's just not convenient enough in 2009. If I'm out with a friend and want to play a multi-player game we first have to find a Starbucks or whatever the heck to get on the same Wi-Fi network. Also, think of the ridiculous amount of social apps you could have if iPhones could talk to each other without needing Wi-Fi. Exchange business cards, flirt with the cute girl over there, etc.
Form a PURE programmers perspective, make XCode as helpful of an IDE as Eclipse or IntelliJ are in the Java world. There's so much time I waste on stupid stuff that the IDE could have found for me as I typed it.
I also don't understand why I can't color buttons without having to use images.
Better multitasking is absolutely key at this point. Android's got it, Palm's WebOS has it - both, it seems, in largely unrestricted and well-implemented fashion. Possibilities:
Push notifications with a good UI (message stack in addition to badging/sound/whatever - if they have to have an extra approval step so apps can't be obnoxious, so be it)
Multiple full processes (not possible with current OS, I realize, but then I've never seen a good explanation why the iPhone doesn't support virtual memory)
Smaller "background" versions of apps that can run in the background - no GUI and a significantly tighter memory constraint
A good mapping API. Let us access the Google Maps abstraction that the Maps application uses !
More Interface Builder goodness
Better simulator
Smart inbox. Incoming messages are routed to installed handlers based on type.
Synchronisation framework that simplifies syncing with desktop & Mobile Me.
Decent landscape support, without the multitude of bugs, especially for the camera picker. Better support for rotation and more control of it.
Access to EXIF data on images from the picker, so we can tell their location
Deeper access to the camera API, so that we are not rail-roaded into the standard photo taker / picker
Push notifications that can launch an application. (In lieu of full multi-tasking, which I don't think we'll get and which could be problematic.)
Better, more intuitive keyboard controls.
API for inter-application messaging.
Access to data from Calendar, iTunes, Mail, Notes and more (with user's permission)
A more accurate simulator, with, for example, ways to limit bandwidth, and use the Mac's camera to actually take a photo.
Phone-phone bluetooth for data exchange
Access to more of the views used by iPhone apps, e.g. the progress HUD, email "blobbing" mechanism for email addresses, thumbnail scrollers, HUD brought up in Photos app, and more.
Less sandboxing. It won't likely happen, but it would always be appreciated for an app to have slightly more power than they currently do (actual filesystem access, for example. even if it was read-only access, it would still allow for more interesting applications to exist).
EDIT: Also, access to the copy/paste API. But I hope that one is obvious to Apple.
My list:
More full-featured IB support as the Mac has
Inter-app Data transfer mechanism (could be C&P, but does not have to be)
Greatly improved camera API with deeper level of control and more flexibility
SDK access to bluetooth and more support for protocols
Real ObjectiveC framework around the address book like the Mac has today.
Warnings similar to the location warning when an app tries to access address book data.
I'm sure whatever they actually have prepared, there will be a few interesting twists.
Ability to send SMS messages without having to have launch the SMS client and have the user type the message.
Access to the raw camera data so that things can be done without having to take a picture and wait for it to save (like you can do with Android)
push notification so that you can launch tasks... would need to be user controllable.
A camera that can focus (I know... have to wait for the next iPhone for that... if they decide to put it in...)
A UIKit level drawing api.
We all know the feature set people want. Copy/Paste, MMS, Flash on iPhone, etc.
I would have thought those specific items were down the SO wish list (although it seems I'm wrong looking at the votes on this comment :-).
MMS is a pretty pointless app when you have eMail. Flash is not an OS issue - Flash could be delivered today.
I don't even want push notifications - they're just a patch, I want background apps. I also want fixes for all the broken APIs like Camera, video and landscape support. Support for CoreImage filters would be nice too but probably too much to wish for.
[[ABAddressBook sharedAddressBook] me] for being able to use the owner's Zip code, phone number, or whatever.
Ability to download files to local storage and sync them back to iTunes or your hard drive
Get EXIF data from photos
Pull all photos at once
Pull all contacts at once
Control screen brightness
Access to music in iPod section
Read access to email and text messages
Access to Safari cookies (so maybe I could make some kind of keep-me-logged-in app.)
fix table view in landscape mode
new camera API with direct access to the camera
distribution code signing automatically when uploading to the app store (instead of code signing in xcode)
ability to request more memory so users don't have to reboot their phones to get rid of background apps
A non-Mac based development envionment.

Is it possible to develop for the iPhone without an iPhone?

I know there are emulators, but is this good enough? If someone is serious about iPhone development, do they absolutely need an iPhone?
Just my personal opinion: if you're serious it means that you're committed to quality of your product. If you're committed to quality there is no way to deliver a product without actually launching it on the target platform :)
As noted in other posts you'll have tough time testing the multi-touch screen and other aspects of the hardware on your emulator.
Don't forget that most types of iPhone apps also work on the iPod Touch, which is a one time cost and no monthly fees. Even network apps work if the iPod Touch is connected to WiFi.
During development of my first iPhone app, I wrote code that worked fine on the iPhone Simulator, but which did not work on the device. So I would say "Yes, you definitely need to test on an actual device."
The simulator is not an emulator. It is not running the actual iPhone OS; it is running a set of Mac OS X libraries that are very similar, but not identical, to iPhone OS. The simulator is great for debugging and saving time during the code-and-test cycle, so you will use it a lot more than the device, but a device is indispensible.
You really do need to touch-and-feel your app on a real device. A UI that works great while pointing and clicking with a mouse might be terrible when used with thumbs and fingers. If there is any text entry, you need to feel how painful it is to type using the onscreen keyboard, to determine whether it makes sense to provide alternative data-entry methods.
There are also significant performance differences between the simulator and actual devices. You need to test with the oldest (slowest) device you want to support to verify it is not too slow, doesn't run out of memory, etc.
As others have suggested, an iPod Touch is also sufficient, so the cost of a device isn't huge. Also, try to find beta testers with a variety of different models.
Necessary: How the app handles in your hands is critical to something like the iPhone. you cannot tell how it will feel to use when plastered straight in front of you in the emulator on a big screen.
If you cannot hold it you won't be getting the true user experience.
If you need to learn Obj-C, go with the emulator for a while until you learn the ropes and save the expense for later. But yes, eventually you will need an iPhone for final testing. How long you can wait will depend on the features that your app uses, If all you are doing is button presses, you can wait a long time. If you are dragging, using location services, etc., you'll need a device earlier in the development cycle.
Are you trying to convince yourself or your boss? ;-)
I'd say you need one. Emulation of such a new device can only go wrong. Plus don't forget the tactile aspects.
The iPod touch is a reasonable substitute provided you are not using:
GPS, BlueTouch or Camera - the iPod touch doesn't have these
Cellular network - although the iPod touch has WiFi, the latency of a cellular network is way way higher than that of a wifi network. If you are doing anything like designing a custom protocol for your application, you will want to check real-world performance - and if you do this too late in the development cycle, you will be in for an unpleasant surprise.
Whether you develop on the iPod touch or on the iPhone, you absolutely must have a device. This is not optional! The simulator is good, but it is not perfect, and there is no substitute for having a device which correctly indicates performance, screen resolution, brightness, form factor and all the other factors that you will need to consider in your application.
If you buy an iPod touch, you will probably end up getting an iPhone too. I'd just go straight for the iPhone. That way you can use it as your main phone, and get a real feel for how the platform behaves and what an application needs to do to make it great.
Kind-of "yes".
Just download iPhone SDK (it's easy and free) and check out the emulator that is in there. You'll see whether that suits your needs or not. The emulator is not indicative of real hardware performance, there's no touch input, some quirks might be different, some things can not work, etc.
The iPhone Simulator makes it easy to test your applications using the power and convenience of your desktop or laptop computer. Although, your development computer may not simulate complicated touch events, such as multifinger touches, the Simulator lets you perform pinches. To perform a pinch, hold Option while tapping on the Simulator screen.
I'd say it depends on the kind of application you are developing. For a successful iPhone app, one which is properly integrated on the system, you are going to need to be able to test your tactile interface. That's hardly accomplished with the Emulator.
So, my answer is Yes, you do need an iPhone to develop iPhone apps. Fortunately, if you cannot afford one, an iPod Touch (200 bucks) is a very competent replacement. The underlying hardware is pretty much the same.
Necessary. If you plan to develop a successful product it needs to be one the end users (not just the developers) find easy to use.
The best way to do that would be to load your app on an iPhone then take it to various people and ask them to use it while you watch them to see if they experience any issues.
Users can get mighty creative in trying to do things a developer never intended - just ask any support tech.
Unless you're app is going to sell for less then $500 total it's a relatively small investment to build a quality app.
If you are serious about development, an iPhone (or iPod touch) is a must. However, the official SDK comes with a very complete "iPhone simulator". This will allow you getting a feel for Objective C and the entire development workflow. The SDK requires Leopard.
You don't need a Mac for this. You can use OSX86 on your PC, either installed on and booted from disk or through VmWare.
It works. In fact, you can even synch the iPhone through Leopard running in vmWare.
Now, testing on a real iPhone is a necessity because of performance, memory usage etc. Also you need it for the entire authentification procedure, getting the keys etc. (if you want to sell your stuff on the Appstore), testing this really requires an iPhone.
If you buy an iPod touch, you will
probably end up getting an iPhone too.
I'd just go straight for the iPhone.
That way you can use it as your main
phone, and get a real feel for how the
platform behaves and what an
application needs to do to make it
great.
I absolutely agree with this.
If you are seriously developing an iPhone application - for fun or for profit - you will have to run it on a real iPhone to test out compatibility and usability at some point. Since you going to have to get one at some point, you may as well get one now. Don't go for half measures. An iPod Touch may be [significantly] cheaper to start with, but will be money wasted when you go and get your iPhone. (Of course, if you are planning an app that runs on the iPhone as well as the iPod Touch, then you MUST test it on both. You cannot assume that if it is good on one it must be good on the other).
Also, by having an iPhone from day one, you can familiarize yourself with its user interface, its norms and the common metaphors the apps use. That will heavily feed into your own application design process, and make sure that your app looks, feels, and works like a first class iPhone citizen.
From experience developing on other mobile platforms, once you get to a certain point, it really is best to have a physical device to test on. If this is something that you would also be using yourself, if it much easier to get some real world type of testing by using the application out and about.
I also think it helps one to understand the platform better by having the device or devices you are targeting with your app,
if you are going to develop native apps for the iphone, I would say get an iphone or ipod touch to target. emulators are good, but eventually you will need to target the real thing. if you are developing web specific content there are lots of things you can do without it (there are some great dev videos free from apples dev site which will only cost you a sign up) but eventually I would think you would still want to test with the real deal
Get a cheap used iPod touch, develop, get money, buy an iPhone 5.
I'm a nokia dev now, I'm thinking of going to iPhone, Actually I have the Mac to work, just the device itself ;)
I've tried iPhoney and compared to my iPhone (Mark 1) it's not the same, it's close - but not close enough to rely on if the interface is of importance to you.
You absolutely need the real device. The performance difference between the simulator and the actual iPhone/iPod Touch hardware is huge. Code that will run nice and fast in the simulator can easily turn out to be too slow to be usable on the real thing. Also the API provided by the simulator is not 100% identical to the real thing, so code that works fine in the sim, may not work on the device. The only way to know for sure is to test often on the actual device.
As others have mentioned, the iPod touch works well as a development device. So if you don't need any of the features of the iPhone, it's a good, cheaper, alternative.