What are the limitations of coding web apps for the iPhone? - iphone

For instance, could a web app access the mic on an iPhone and transmit voice back to a server?
Or is it possible to build Safari extensions for the iPhone that can operate transparently on a web page? For instance, is it possible to build an extension that removed ads from Google result pages for the iPhone, without the user clicking any buttons to activate the ad-removal functionality?

You pretty much hit the main limitations.
You have no access to hardware that's not supported by HTML5 (geolocation is, but things such as acceleration and audio/video recording are not).
You can't build Safari extensions for the iPhone at this time, you can only use JavaScript like usual.
Some frameworks like PhoneGap make attempts to provide more hardware features via a native app container, but it appears Apple is trying to prevent those apps from going on the App Store, to some extent.

Related

Can you bundle an Objective-C iPhone app and an HTML5 (PhoneGap) iPad app to make one universal app?

The apps provide the same functionality, but have different code bases.
Is this possible?
I'm not entirely sure what you mean by "bundle" in this instance. PhoneGap provides the ability to deploy your app to numerous platforms (iOS, Android, Windows Phone) by writing in just HTML5, CSS, and Javascript. Your question states that you have a functioning HTML5 version of the app written for the PhoneGap platform. If this is the case, what is the need for the Objective-C iPhone app? Simply maintaining the HTML5 app should be sufficient to deploy to both iPad and iPhone. PhoneGap currently supports iOS, iPad, and retina displays.
From the PhoneGap documentation, you can specify differences in your interface using config.xml.
You can mix phonegap and native code fairly easily - just have the startup code check the platform type and display either the native view or the phonegap webview.
However, whatever you do at this point will result in some inconvenience to users - the only way to share in app purchases across devices is to have a single universal app. If you want to keep existing purchases, you have to add an ipad view to the existing iphone app, but that will not show up as an update for anyone who has the existing iPad app.
There are other possibilities such as setting up a server to track purchases in both apps, but that gets a lot more complicated than standard in app purchase and only works if your app includes a login system.

How to gain direct access to the hardware capabilities of mobile devices from mobile browsers

We are developing web browser application for mobile phones and I am trying to figure out a way that I can gain access to the camera and take a photo and then upload it to the internet. But so far what I was suggested is to use phonegap and create native application. Phonegap is fine but it is not what I am looking for because my client wants to design forms and these html forms somehow will be able to trigger the camera and take photo and upload it to a server. Do you think developing a native API for every platform and having access to its functions from the web browsers is possible? What your suggestion would be?
(Note: My customer only want application that can run on mobile web browsers no native application runs on I-Phone, windows mobile, Blackberry and Android)
Thanks a lot...
Web apps (not wrapped in native code as Kumar details) cannot access all device hardware and sensors. Location support is available on iOS and Android, but camera access is only available on Android (via JavaScript). Similarly, device motion APIs are not accessible on Android, but are on iOS.
As you can see, support is sketchy and if you are truly looking to use such features, you are better off (and in many cases, realistically looking at) writing native apps for each platform you intend to support.
HTML5 is not yet at the point where it can replace native apps. It can do some of the things that native apps can, but even then performance is suboptimal. Currently, native apps may be more difficult and time-consuming, but they are necessary.
Calling android native APIs from javascript functions of embedded WebView
Use JS to call Java code which will in-turn call the Camera API or whatever else you are looking for.
It's not going to be possible to do it on iPhone, the only known way of accessing the camera is through the Cocoa layer.

Android, Iphone app with JS and HTML

I have read some post about apps programming for Iphone and Android, but I have one question. Is it posible when there is a mobile website optimized for mobile phones, that I can create apps for Iphone, Android, Win 7 and Blackberry, that only statrts the browser as instance and display the mobile website? What do you think, is this ok? Do you have any ideas or examples for that kind of apps? I mean this is not an app, that should be has access to the hardware of the phone, only web app.
Thanks
Nik
This would work.
You could create an app that consists merely of a webview into which you load your content. The content could be loaded over the mobile network or be stored locally.
However most users (including yours truly) strongly dislike apps that merely present a single website to the user, because of the long delays if the content is loaded over the mobile network every time and because the UI is, in many cases, very different to what the he or she is used to from native apps.
Most users fail to see the need for a specialized app just to visit a website which they could as well keep as a favorite in their mobile browser. On the iPhone, you may even add favorite websites as icons on your homescreen, so there is no need for apps presenting a single website at all.
It's not only possible, such things are already done. One example I know of is cookd, a restaurant guide for Vienna. But there are some constraints; for example, cookd requires GPS data for the "Nearby" option; on my Android phone (HTC Legend), this is possible when I open the web page directly in the browser (the browser asks if I want to allow cookd.com to get this info); but the same webpage, running in an application that does nothing more than display the browser component, cannot do that. To fix that, they would have to build GPS reception into the app and forward this info to the browser component.
O'reilly has a fantastic article about this:
http://building-iphone-apps.labs.oreilly.com/
This is a little bit directed to iPhone only, but will give you a good overview about the topic and possibilities.

Can I successfully do iPhone/iPad website development/testing on Windows?

Can I successfully do iPhone/iPad web development (not native apps) on Windows, and without having an iPhone/iPad device?
I.e. work like PSD-to-iPhone-optimized XHTML/CSS layout.
I’m interested to learn about and make iPhone/iPad optimized websites. Any tips? How different will it be from desktop? What’s different other than the smaller screen?
From experience I will say the only true way to test for the iPad is to test on an iPad. I have been developing a site in html5 specifically for an iPad and we initially used the iPhone to test. The drag function we had implemented with jQuery had worked almost perfectly on the iPhone but after the client had tested on the iPad they came back to us and said the function did not work period and they were correct.
I guess this could change depending on what type of development you are doing. From experience I would say either A. Make some trips to the apple store B. Make friends with iPad owner C. Buy and iPad
yes for an ipohne emulator... try MobiOne.
It's a good application to test the pages in iphone like environment.
http://www.genuitec.com/mobile/
I don’t think you can really do iPhone/iPad development successfully without an iPhone/iPad at all, whether on Windows, Mac or Commodore 64.
If you’re serious about iPhone/iPad development, how could you not try your software out yourself on the devices it’s going to run on? Your clients are going to want code that works on the iPhone/iPad. You need an iPhone/iPad to check that it works.
if your developing a web app then i think you can use this: http://ipadpeek.com/
The answer is: Yes you can absolutely do iPhone and iPad website development on a Windows PC.
However, you really should/must test the result on an actual iPhone/iPod Touch/iPad. Especially if you are integrating in any way with special device features like the dialing feature of the phone. (Yes you can have phone numbers in a webpage trigger dialing when you tap on them.)
However, you can do the bulk of the development on Windows, testing the WebApp in Safari or Chrome, which are the most fully compliant HTML5 WebKit based browsers out there.
Also highly recommend using an HTML5 touch framework like jQuery Mobile or Sencha Touch. This will go a long way to ensuring that your WebApp is optimized for the screen size and touch gestures of the mobile devices.
Remember that you can't deploy a pure WebApp to the app store, only download it from a website. You'll need a native wrapper like PhoneGap for that. And to compile a PhoneGap wrapped WebApp you'll need XCode on a Mac.
But there's a lot of power in adding your WebApp to the home screen on iOS. No native code involved and you get a full screen webapp with a home screen icon, loading image and no browser toolbars. Highly recommended.

Iphone App vs. Offline Web App. Which way is the smartest?

I think about starting from scratch building a small application fullfilling two technical requirements:
should be usable on iPhone
should work offline
There are two obvious alternatives here to choose between
A real iPhone application with offline capabilities
A web app using HTML5 offline, Google Gears or similar
Having no iPhone app development experience (I don't own an iPhone), i wonder which way would be the easiest to go?
What are the learning curves for building offline HTML vs building an iPhone app?
Honestly, it depends what your app is going to do.
MobileSafari supports all the HTML5 offline stuff, so you could store data in a clientside SQL database, cache the application clientside, etc... The mobile Gmail app is probably the most notable example of that, giving you full-featured access to your Gmail even when offline. You can also use geolocation through JavaScript APIs that were added in 3.0. Web Clips let your web app share the home screen with native applications too. There is more on using web apps on the iPhone on this Stack Overflow post.
Obviously, doing a Web app will be of interest to people who like dealing with HTML, CSS, and JavaScript (and possibly whatever language is running server-side). It is possible to do really neat stuff with offline Web apps, but its performance won't be as good as that of native apps, especially on pre-3GS devices.
Developing a native application will require you to learn Objective-C (or C# as soon as Mono Touch is available to the masses) and pay a $99 fee to be allowed to test on-device and deploy to App Store. A lot more of the system is exposed to you through the various APIs, such as the camera, compass, multitouch, and so on.
Objective-C is pretty simple to pick up if you're familiar with Java; you only really need to get used to the square bracket syntax and memory management and then it's pretty straight-forward.
Then there are the hybrid systems, like PhoneGap, which expose more of the device's APIs, provided the Web app runs in a special container app. It is also crossplatform, so you could also deploy the app on Android and BlackBerry if you wanted to. This still requires you to pay the App Store fee, but if you're more familiar with Web development, this gives you the best of both worlds.
I can't tell you too much about HTML apps in general, but I can tell you that the API for the UIWebView is extremely minimal, and of course there is much less you can do than in a native iPhone application.
An HTML5 offline app would have security issues as you would have to hard code your oauth secret into code that anyone could see ( by clicking view source, or inspecting in Firebug ). You could simply use http auth, but then you get the ugly "from API" credit with every tweet sent from your app, and also that ugly http auth popup from the browser.