PhoneGap supports a wide variety of platforms:
- Windows 8
- Windows Phone 7 and 8
How does PhoneGap works?
PhoneGap takes your web application and renders it within a web view. Web view is a native application component, which makes web content to display within a native application.
Applications built with PhoneGap use the mobile platform’s Web view to render content. As such, the content will appear nearly identical on each platform, much as any Web page would. While you can style the controls differently on each platform, take care in doing this.
What is PhoneGap Build?
Plugins: Closing The Gap On Native Features
- file system,
- media playback and recording,
- network availability.
A full list of capabilities for each platform is available on PhoneGap’s website. If these capabilities aren’t enough, PhoneGap may be extended with plugins that enable the developer to access more device features, including these:
- barcode scanning,
- push notifications,
- text to speech,
- Facebook Connect.
In previous versions of PhoneGap, a GitHub repository contained a set of prebuilt plugins. With the arrival of PhoneGap 3, a new plugin architecture has resulted in the old repository being deprecated. A registry has been created for all plugins compatible with PhoneGap 3.
Some command-line tools are also provided to make it easy to add the plugins to the repository for your project. We’ll see these later on in this article. PhoneGap also publishes documentation and examples on how to write your own plugins. Of course, development of plugins assumes familiarity with the native platform on which the plugin is to be supported.
The majority of PhoneGap’s capabilities lie in non-visual components — things that access the file system, network availability, geolocation, etc. PhoneGap does not provide much assistance with building the user interface itself. For this, you must rely on the HTML and CSS foundation that you’ve built yourself or on a framework. Applications written for mobile browsers must respect the limitations of the given mobile platform (processing speed, screen size, network speed, touch events, etc.).
Unless you have been working with HTML and CSS for a long time and are well aware of these issues, developing an effective mobile application without some sort of framework can be daunting.
Fortunately, some mobile frameworks have arisen to help with this. Here are just some of the offerings in this area:
These frameworks vary from CSS-oriented libraries (like Topcoat) to complete MVC-based libraries with sets of mobile UI controls (like Sencha Touch). Discussing the differences between these frameworks in detail is beyond the scope of this article and would require an entire series of articles. Visit the websites above and try some of the demonstrations on several mobile devices.
One distinction to be made is that some frameworks support a wider variety of devices and device versions than others. Some mobile frameworks are built on a particular MVC platform. For example, Ionic is built on the AngularJS framework. This might make a particular library more attractive to developers who are already familiar with the respective MVC framework.
Frameworks such as Sencha Touch abstract the DOM from the developer through the use of APIs, freeing the developer from having to worry about details of browser vendor implementations. Sencha also provides graphic development tools, such as Sencha Architect, to aid the development process. Sencha provides commercial support and training, too, which are worth investigating.
I’m often asked to recommend a framework for mobile development. But the right tool depends largely on your application’s functionality, the mobile platforms you need to support, your demand for commercial support and your experience with Web and mobile development in general. I’m encouraged by some emerging frameworks, particularly Ionic, but as of the time of writing, Ionic is still in the alpha stage. If you are looking for something with a longer track record, then Sencha Touch or, for some cases, jQuery Mobile might be appropriate.
To be expedient and because of the wealth of tutorials and documentation available, I’ve written our FasTip application in jQuery Mobile, which provides a wide range of support for mobile devices. It’s a good choice for applications that do not require significant customization to the user interface. The simplicity of our application makes it well suited to jQuery Mobile.
PhoneGap Or Cordova: What’s In A Name?
In the process of learning about PhoneGap, you’ll encounter the name Cordova. In fact, the command-line tool that we’ll use in just a moment to create our PhoneGap project is named Cordova. Simply put, Cordova is the open-source project that is the basis of PhoneGap. Think of it as the engine that drives PhoneGap.
In most cases, the names may be used interchangeably. With “PhoneGap” already being trademarked, a new name was needed when the project was open-sourced — hence, Cordova. “PhoneGap” continues to be used by Adobe for commercial products. Most people still refer to
the project as a whole as PhoneGap.
With the introduction of version 3, installing PhoneGap’s tools and setting up projects have been greatly simplified, thanks to the new command-line interface(or CLI). The command-line tools are based on Node.js; thus, you must install it before installing PhoneGap. Once Node.js is in place, simply run one command for the node package manager to install PhoneGap’s tools:
npm install -g cordova
Considerations For Supporting Multiple Platforms
We’ve seen that, by using PhoneGap and a framework like jQuery Mobile, building a cross-device application is easy. One caveat with jQuery Mobile is that both iOS and Android users would see the same UX; that is, the UX would not be tailored to the respective platform, much like a Web page looks the same whether viewed on OS X or Windows.
Attempting to mimic the native platform controls in HTML and CSS is generally a bad idea. While you could approximate the look of the native platform, mimicking the feel of the platform is exceedingly difficult. The controls might not respond to taps and other gestures in exactly the same way. The result is usually a UX that just feels wrong. Successful PhoneGap projects generally eschew this approach in favor of a platform-independent UX.
If your project requires an experience that closely matches that of the native platform, PhoneGap might not be the right choice.
HTML5 capabilities vary widely across devices. While iOS and Android browsers are built on WebKit, some features are implemented only in the latest versions of the platforms. One useful website for checking browser version capabilities is Mobile HTML5. The browsers on some old platforms, particularly Android 2.x, have various rendering bugs, which could also hamper your development.
Frameworks such as jQuery Mobile and Sencha Touch take these compatibility issues into account. If you choose to roll your own solution, perhaps to gain greater control over the UX, then you will need to plan additional time for testing, particularly for old device versions, on which HTML5 support is less consistent.
jQuery Mobile makes it easy to get started and provides a good feature set for simple applications. Much of the functionality on the screens of our sample application is provided by jQuery Mobile itself, leaving us with less code to write. However, the speed of development with jQuery Mobile comes at the expense of customization. While jQuery Mobile does offer a “theme roller” tool to customize appearance, much of that is “chrome” related to colors and visual attributes like rounded corners.
Assess whether your application fits jQuery Mobile’s paradigm. The platform does offer some alternate layouts for things like forms, but the options are still somewhat limited. If your application requires a truly custom look or layout, then you might find jQuery Mobile too confining. Consider one of the frameworks suggested earlier. Or adopt a “best of breed” approach, mixing a CSS-oriented framework (such as Twitter Bootstrap, Zurb Foundation or Ratchet) with an MVC framework (such as AngularJS or Backbone.js).
Some of the large mobile solutions, such as Sencha Touch and Ionic, marry a powerful MVC platform to a set of prebuilt controls focused on mobile development. These tools are attractive and worthy of consideration. But bear in mind the different range of devices that each of these tools supports. At the moment, Sencha Touch supports more devices than Ionic, but jQuery Mobile supports even more. This should also factor in your selection process.
Using A Native Plugin
If you try our sample application on iOS 7, you’ll run into an issue with the device’s status bar that has affected many PhoneGap applications. That is, the status bar now overlaps the top of the application:
Building In The Cloud
Generally speaking, to build an application for a particular platform, you must install the SDK for that platform on your machine. This could be a problem if, for instance, you’re on a Mac and want to target Windows tablets, whose SDK requires you to be on a Windows machine. Adobe offers a service named PhoneGap Build to help in this situation.
This means that testers will always be running the latest version of your application, without having to go through the traditional updating process. Note that, at least for now, Hydration is meant for development and testing — not for final production code that will be submitted to the app store.
Development in the Cloud
You can do more than simply compile and package your application in the cloud. Cloud-based Icenium provides a browser-based IDE that lets you edit code in a browser and immediately turn those edits into a deployment package. Using an application in the iOS App Store named Icenium Ion, you can dynamically load updates to your application as you change the code in the Web-based IDE.
In addition, Icenium bundles a license to Telerik’s KendoUI library. I’ve used this to make changes to an iOS PhoneGap application while on a Windows-based laptop. Icenium also offers a Windows desktop IDE named Graphite, which expands on the capabilities of the browser-based tool.
Another alternative to PhoneGap Build is AppGyver. It is not an IDE like Icenium, but it does offer a UX library, named Steroids, that facilities navigation between Web views using some native controls. Note that for page content itself, you must still use HTML and CSS.
The main downside to cloud-based development services is that they have limited support for PhoneGap plugins. However, new plugins are being supported all the time. Determine your application’s needs to see whether a particular cloud-based tool supports the plugins you require.
Debugging Your Application
I generally find it easiest to work with Chrome DevTools by treating my pages as standard Web pages loaded in a desktop browser (although this doesn’t help with the portions of code that rely on PhoneGap plugins). Chrome DevTools provides an emulation panel that simulates the aspect ratios, touch events and more of various mobile device screens.
Safari to debug web views on iOS Apps
Chrome DevTools to debug web views in Android Apps
Starting with version 4.4, Android’s Web view is now based on Google Chrome. With this change comes the ability to connect to the Web view from DevTools and to debug interactively, just like you can with iOS. If you don’t have a 4.4 device, fear not: It works with the 4.4 emulator as well. Note that you’ll need to add a special plugin to your PhoneGap project to enable Web view debugging on Android.
Web Inspector Remote
The PhoneGap wiki also has a page on debugging, with links to other tools.