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Visual DataFlex on Mobile Devices Presentation Scanduc 2012

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In November 2012, Mike delivered a presentation about developing and using native iOS apps with Visual DataFlex web services. A summary of the slides is given below.


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Visual DataFlex on Mobile Devices
Mike Peat – Unicorn InterGlobal Ltd, UK


Visual DataFlex and mobile apps  – the landscape

Mobile touch-screen devices are increasingly pervasive:

  • iPhone & iPad
  • Android phones and tablets
  • Windows phones
  • The new Microsoft “Surface”

People use these to browse the web…

However…


Web sites vs. web applications

  • Web sites
    HTML-formatted content – may have lots of tricks involving CSS, JavaScript, images, streaming media (music and video) and so on, but basically serving up content
  • Web Applications
    Full blown UI applications written in JavaScript, delivered to the browser over HTTP and then communicating with the server as a provider of back-end services – data and logic

VDF Web applications – the user experience

  • Mobile device web browsing is OK (mostly)
  • But how do web applications fare?
  • Let’s take a look…
  • We’ll use the new VDF 17.1 AjaxWeb app:

    https://www.unicorninterglobal.com/AjaxWeb/Index.html
Example iphones for AjaxWeb

VDF web applications on mobile devices – some of the problems

  • The lack of screen real-estate is the most obvious (although that was an iPhone – iPads are a little more generous)
  • The on-screen keyboard is an issue – the browser has a strategy for dealing with this, but its behaviour is hardly satisfying
  • Changes in device orientation can also make a mess of our layout

VDF web applications on mobile devices – addressing the issues

  • One answer is native apps for the target platform
  • Can use web services to connect to VDF – just as the JavaScript application in the browser does
  • Greater control of the device
  • Let’s take a look at a simple (or maybe a “dumb”) one…
Native iphones example

Using native apps for the target platform  – Is it better?

  • Well… maybe…
  • …or maybe worse!
  • Even with native apps we are going to have to do better if we are going to produce something useful
  • Let’s see what that might look like…
Native iphones better

So, is the more controlled approach to using native apps better?

  • I think so
  • We deliberately gave up our screen space to the keyboard
  • We controlled what screen orientations we were going to support
  • We were able to live (just!) in the available space

So how do we build a native iOS (iPhone or iPad) app?

  • If I still have time…
  • Let’s see what is involved in building a native iOS (iPhone or iPad) app that uses VDF web services
  • Watch this space…

Is using native iOS apps with VDF web services good enough?

  • Here I am less sure…
  • The utility of these devices as general purpose data entry platforms is itself moot
  • We were restricting ourselves to an iPhone layout – an iPad layout would have given us more space to work with
  • We may have to adopt different design approaches for mobile platforms

Try the free demo app

We have uploaded the app to the App Store for you to download and try out. Download Free Now or search the App Store for Scanduc12.


Thank you!

Any questions?