Is it possible for me to programmatically access a smartphone's sensors (e.g. accelerometer, compass, etc. on an Android or iPhone device) through a browser webpage and JavaScript? I know that the W3C Devices standard can allow access to the camera.
HTML5 is likely to contain a sensor API. Until this is fully standardized, vendors provide their own APIs such as Apple does for mobile Safari.
There's no need for full blown solutions like PhoneGap or similar if it is Ok for you to restrict yourself to a specific vendor/device. If not, frameworks like PhoneGap provide you with a unified, device independent API.
You should be aware of the Performance constraints that apply to Javascript applications running inside the browser of a mobile device. Depending on your type of application and the amount of processing you intend to do on the sensor data, you are better off writing a native application
See https://developer.apple.com/library/safari/iPad/#documentation/SafariDOMAdditions/Reference/DeviceMotionEventClassRef/DeviceMotionEvent/DeviceMotionEvent.html for some reference documentation.
The answer is both "yes" and "no". Each phone manufacturer/OS combination behaves as it sees fit here - for example, the GPS on an iPhone can be accessed, but the compass not:
accessing iPhone compass with JavaScript
You can use something like PhoneGap to do this, I believe.
Check out this chapter called "Controlling the iPhone with JavaScript" from the book Building iPhone Apps with HTML, CSS, and JavaScript
This demo considers the iPhone movements on the three axis using the event.accelerationIncludingGravity object:
http://www.omiod.com/iphone/acceleration-demo.php
So far Safari on iPhone is the first to implement it, but I see Android filling this gap very soon.
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I'm very new to mobile app, and having difficulty finding the right direction to move ahead with our current project. I hope to receive some insights, suggestions from the experts here based on your experience.
Below are are main features our project needs:
1. Get user current GPS location and send to our server (and receive a list of location to display)
Take picture and perhaps even video with phone camera (if available) then store and send to our server when the users want to (in case they do not have free wifi at the mean time, they may decide to send later)
Join chat rooms (hosted on our server)
Store certain info (location info such as address/fone etc and chat logs for offline usage)
We want to support iphone and android first, budget is also a big concern.
If you use the native app approach, it means you will have to code separately for both android and iphone platforms.
Considering your budget concerns, PhoneGap and Appcelerator should work for you. Both are powerful platforms. But before choosing either of these, consider a few points about each of them.
If you choose phone gap, you will be coding in HTML, css and javascript. Also you will be building a mobile web application.
If you choose appcelerator titanium, you will require only javascript skills to develop app and the look and feel you get will be closer to the native app. There might be a slight performance delay with the android build of it as compared to iphone, which is acceptable in most cases.First go through its demo (Kitchensink project), then decide if this platform suits you.
We are going to redevelop one website we developed as an ASP.NET website to be a mobile one.
So, I'm wondering how does the development of a mobile website differ from a normal one?
Also, what is the best approach to do this taken in consideration that this mobile website will be browsed mainly from iPhone?
There are a number of differences between a mobile device and a standard computer.
The screens are much smaller (fewer pixels to display your page). You should put fewer elements on each page.
They are typically viewed in portrait mode (narrow display - narrow page). You should plan on using the full width of the screen instead of setting a fixed page width like most people do on standard web pages.
People use finger gestures to manipulate the page instead of a mouse (buttons/links should be larger)
They can include additional features such as geo-location, telephone, etc. that you can incorporate into your app to be easier to use. There are some libraries available to help you use these, such as jQuery Mobile.
Users are concerned about battery life plus the CPU tends to be slower. Make sure you keep animations and client side processing to a minimum.
Users are concerned about data usage. Keep ajax calls to a minimum (don't ask the server for data every few seconds!) and use graphics sparingly (it's better to use html/CSS to make the page attractive).
Flash isn't supported on iPhone and is not well supported on other devices. However, most mobile devices have decent support for HTML5, so you can typically use that instead.
Users on smartphones are used a different experience.
In addition to Brian's answer I'd add:
Screens are not resized but scrolled, however sides scrolling is not generally a good experience
Screens orientations can change, but the same scrolling rules apply
Consumers are used App like behaviour and as such less information with backwards and forwards between pages is common and between sites
Consumers generally have data concerns so data traffic needs to be minimised
Controls/buttons/selections/data entry need to optimised for hand gestures - for example think of what happens with the keyboard pops up to allow data entry, how much screen is available - can the see all their input easily if they need to?
I suggest that for developing a mobile website is to use the target smartphone for a few weeks to understand how the device is used in the real world.
I'm afraid you cannot use current asp-View to mobile especially for iPhone. There's special control set for iphone development - componentone.
If you web application is based on MVC or MVP patterns then moving will be not difficult.
Recently we have developed a site for iphone users, we are using asp.net/sql for normal site.
But when you look at mobile sites, mobile normally have small screens and some time optimization problem.
We use jqtouch for mobile development. A JQuery plugin for mobile web development on the iPhone,Android, iPod Touch, and other forward-thinking devices.
Learning Video
Getting started
Establish the context for the mobile site: is there subset of information that is more relevant to your mobile users? Maybe your regular site has apps that are irrelevant on mobile devices? Either way, you should create your mobile site separately in a mobile folder! You can then use a sub-domain to reach it: for example, http://m.mysite.com
You can use a combination of CSS Media Queries and 51degrees.Mobi to detect browser features and render the correct size layout depending on which type of device the user has.
http://html5boilerplate.com/
http://www.modernizr.com/ (this is included in HTM5 Boilerplate)
http://51degrees.codeplex.com/
Do not make the stupid mistake of following current fads like "Responsive Web Design" which attempts to squeeze a desktop version of a website into a mobile screen. Above links should get you started.
Is it possible to run Safari in the background on the iPhone?
Specifically, our client would like to monitor a user's location via HTML5 GPS capabilities and measure the speed of movement.
The reason for avoiding native implementation in iOS is because the client wishes to create a cross-platform service using HTML5.
Is this possible?
I don't believe Safari continues to execute when it's backgrounded. (This is supported by a recent thread on the Apple discussion board.)
That said, it would be fairly trivial to do this in a proper iOS application, although you'd obviously need existing knowledge of Objective-C, some of the main Cocoa/UIKit classes, the Xcode environment, etc.)
I am currently developing a location based iPhone application. Is there any way to test the app other than taking the iPhone to different places?
Thanks
Yes, you can.
Try this: http://www.vimov.com/isimulate/
(...) With iSimulate installed on their iPhones however, their multi-touches on the iPhone (which gets interpolated for the larger iPad screen), the movement recorded by the accelerometer, the location and orientation captured by the GPS and Compass, all get wirelessly sent to the iPad Simulator, so they can develop virtually any application they want, before the iPad is itself released!
Even though an answer have long been accepted for this question I'll still chime in with some additional information on the topic.
The kind folks at FutureTap have mad the FTLocationSimulator available for free at GitHub. It allows you to prepare a test route using for instance Google Earth, and then have the simulator feed these coordinates to your app.
I've written a blog post about how to use FTLocationSimulator to easily switch between multiple routes during testing of the location features.
Which of the new features are you looking forward to the most in iPhone SDK 3.0?
Is it one of the main advertised six new things, or something smaller? Something in the "1,000 new APIs", perhaps?
Phone to phone communication via bluetooth seems like it will terribly useful for some apps I am writing. No longer do you have to input all the data you want to store yourself, you can share some of it with other iPhone users.
not really a feature, but the best thing about developing the iPhone SDK further is the great frameworks that arise. there are some really, really great frameworks out there already (like the Three20 project) which will become even better with the new 3.0 SDK.
my real excitement will take over once they let us run background processes. maybe in 4.0?
Video! The ability to write decent tools for mobile video uploads is a big draw.
MapKit by far will bring the biggest change sweeping across the app space.
My personal favorite is that we can finally easily track upload progress of large files (like images).
I really, really want to see fixes in the camera API so that it isn't either broken (2.2.1) or forcing a switch to portrait (3.0).
Apart from that, the most useful features to me are:
push notifications. Great for making an app more sticky - you can let the user know that something of interest to them has happened.
CoreData - I've been using a third-party SQL layer, but it's a little buggy and no longer supported.
Peer-peer bluetooth, as the poster above said, is also useful for local data exchange.
And the least useful? Cut and paste. I actually want to disable it in my app (to discourage people from copying content) - and it doesn't look as though you can (yet).
Bluetooth phone-to-phone communication with GameKit will enable a host of currently impossible applications. Multiplayer games with no WiFi network needed and data exchange between two phones are obvious use-cases.
I'd also like to see - not currently included in the betas - a decent camera API that allowed us to customize the appearance of the capture screen, and as another poster said, have it work properly in landscape and portrait mode.