How to perform feature detection and use polyfills

The best way to detect support for particular HTML5 features is to use JavaScript to perform a test for a given feature. Unfortunately, there is no standard convention to test for each of the different APIs, since each of the tests you need to perform are different. Thankfully, there is a small JavaScript library named Modernizr, which will give you a simplified interface to detect all of HTML5’s features. This allows you to easily provide fallbacks where a feature is not supported.

You may also be wondering how to provide fallbacks for given HTML5 features. Of course, you could write these yourself, but this is generally unnecessary as there are many JavaScript shims known as “polyfills” out there that take care of this for you. Polyfills can be quite bloated, so you should only load them if necessary. This is made easy by the YepNope.js micro-library, which is built-in to the Modernizr library itself.

An example of using a polyfill might be for JSON support. Modern browsers all include native JSON as a standard, but there are a number of older browsers that don’t understand JSON at all. In this case, you would most likely use Douglas Crockford’s json2.js script as a polyfill to provide older browsers with JSON parse and stringify methods. To only load this polyfill when required using YepNope.js, you would use the following code:

yepnope({
test: window.JSON,
nope: 'json2.js',
complete: function () {
var data = window.JSON.parse('{ "json" : "string" }');
}
});

Paul Irish, lead developer of the Modernizr library, maintains an enormous list of polyfills for virtually every feature of HTML5, CSS3 and related standards and languages. You can find it on GitHub.

These techniques will help make sure the largest possible audience of users can take advantage of your HTML5 applications.

Safari Books Online has the content you need

Take advantage of these HTML5 resources in Safari Books Online:

	HTML5 and CSS3 in the Real World is ideal for any developer who wants to use the latest generation of Web technologies in their everyday work.
	HTML5: The Missing Manual shows you not only how HTML5 works, but also how to best use its new features to create an effective Web experience for your visitors.
	HTML5 Developer’s Cookbook provides you with all of the expert advice and proven code you need to start building production-quality HTML5 applications right now.

About the author

Joe Lennon is a Web and Mobile applications developer from Cork, Ireland. He works as Product Manager of Mobile Solutions for Core International, one of the UK and Ireland’s leading enterprise HR software vendors. Joe is the author of Beginning CouchDB, and is co-author of the forthcoming title HTML5 in Action. He is also a regular contributor to the IBM developerWorks library. You can learn more about Joe and his work on his website at http://www.joelennon.ie.

This webcast is for developers who want a deeper understanding of how .NET works, to gain the necessary tools and use them to debug and solve real world problems that cannot be fixed with regular debuggers.

Hewardt is the author of Advanced .NET Debugging from Addison-Wesley Professional. Watch his webcast on debugging .NET code now, or check out our entire list of free Safari Books Online webcasts.

In order to programatically detect movement on your mobile device, you must access the DeviceOrientation event specification. This spec defines three events for handling physical orientation and movement changes in a mobile device. This essentially grants developers access to the accelerometer, gyroscope and compass in the device, enabling the development of applications and games that allow the user to control the app by moving the device rather than touching elements on the screen.

deviceorientation

This event fires whenever a significant change in orientation occurs. It uses compass and gyroscope sensors to detect the direction and rotation of the device. Don’t confuse this event with HTML5’s orientationchange event, which merely checks if the device is in portrait or landscape mode. The deviceorientation event returns much more detailed information.

devicemotion

This event fires whenever the device is moved, and in addition to the rotation and direction data returned by the deviceorientation event, it also returns acceleration data made available by an accelerometer sensor in the device.

compassneedscalibration

If the device includes a compass, this sensor may need calibration in order to produce accurate results. This event is fired whenever the compass needs to be calibrated. By default, developers should not need to worry about this event, as browser vendors should provide information to the user about how to calibrate the compass. If desired, the developer can cancel the default event action and provide custom guidelines instead.

Safari Books Online has the content you need

The following HTML5 titles in Safari Books Online will help get you started creating mobile HTML5 apps.

	HTML5 Developer’s Cookbook provides all the expert advice and proven code you need to start building production-quality HTML5 applications right now.
	Pro Android Web Apps: Develop for Android Using HTML5, CSS3 & JavaScript will help you develop HTML5 mobile Web applications.
	Build Mobile Websites and Apps for Smart Devices provides practical, up to date information on all aspects of Mobile Web Development.

About the author

Joe Lennon is a Web and Mobile applications developer from Cork, Ireland. He works as Product Manager of Mobile Solutions for Core International, one of the UK and Ireland’s leading enterprise HR software vendors. Joe is the author of Beginning CouchDB, and is co-author of the forthcoming title HTML5 in Action. He is also a regular contributor to the IBM developerWorks library. You can learn more about Joe and his work on his website at http://www.joelennon.ie.

There are some modules that will be used on almost every site:

• Views allows you to use a user interface to create complex database queries, use the URL path to restrict the query in different ways, and visualize the result with many different plugins.
• Google Analytics places the analytics code on your pages so you can find out who’s visiting your site.
• Wysiwyg lets you configure the text formatting buttons for content editors. While wysiwyg support is expected in Drupal 8 core, it is still a separate module in Drupal 7.

For the more advanced functionality, though, it can be tougher to figure out which modules to use. Here are some tips for finding and evaluating modules:

• You can search the list of modules and narrow your search by category, such as “Evaluation/Rating.”
• If you find a module that does almost what you want, but not quite, check out the related modules in the right hand sidebar.
• Read the blog posts on Planet Drupal regularly (especially Lullabot’s Module Mondays) and follow a few top-notch Drupal developers on Twitter. You could even go to meetings of your local Drupal users group to get tips on the hottest new modules.
• When evaluating a module, check its usage, which is available above the download links. While popularity isn’t everything, especially for new or niche modules, high usage does indicate that a module is useful. It also indicates the number of people who depend upon that functionality, hopefully including developers and companies who can invest time in bug fixes and feature requests.

Don’t be afraid to download a module and try it out. Just make sure that you have a separate version of your site for testing so you don’t have to worry if the experiment goes bad.

Safari Books Online has the content you need

Here are some great Drupal resources in Safari Books Online that can help you with your Drupal modules:

	With the recipes in Using Drupal, you’ll take full advantage of the vast collection of community-contributed modules that make the Drupal web framework useful and unique.
	The Definitive Guide to Drupal covers every aspect of Drupal, from planning a successful project to making a living from designing Drupal sites, and even to contributing to the Drupal community yourself.
	Drupal 7 Module Development is a practical, example-based approach to introduce PHP developers to the powerful new Drupal 7 tools, APIs, and strategies for writing custom Drupal code.
	Drupal 7 Social Networking provides careful instructions and clear explanations to take you through the setup and management of your social network site, covering topics from users, to marketing, to maintenance.

About this author

Lin Clark is a Drupal developer specializing in Linked Data. She contributed to the RDF in Drupal 7 core initiative, created SPARQL Views as part of the 2010 Google Summer of Code, and has spoken extensively about the benefits of using Linked Data technologies in everyday applications. She attended Carnegie Mellon University and is currently pursuing a research Master’s at the Digital Enterprise Research Institute at NUI Galway. More information is available at lin-clark.com.

• Animation and 3D via requestAnimationFrame, 3D CSS transforms and WebGL. Don’t be surprised if you find blockbuster games being released on the mobile Web in the coming year.
• Improvements in file interactivity with the FileWriter API and the sandboxed FileSystem API.
• Widespread support for IndexedDB should (finally) arrive in 2012. The need for a standardized interface to an indexable client-side database on mobile devices is growing larger by the day. With Web SQL dead for some time now, I highly expect iOS, Android and other platforms to introduce IndexedDB support in the coming year.
• Both Google and Mozilla are working on (separate) implementations for the playback, generation and processing of audio streams. Expect to see rapid growth in this area in 2012.
• Two APIs that will vastly improve the Web experience on the desktop are the Full Screen API (allowing Web pages to take over the entire screen) and the Page Visibility API (allowing Web pages to detect if they are no longer visible; i.e., if the user has switched windows or tabs to make the page inactive).

Safari Books Online has the content you need

Get started developing with HTML5 now, by tapping into Safari Books Online:

	Using the HTML5 Filesystem API shows you how by using the FileSystem API, a web app can create, read, navigate, and write to a sandboxed section of the user’s local file system.
	Pro HTML5 Programming teaches you how to use the latest cutting-edge HTML5 web technology — available in the most recent versions of modern browsers — to build Web applications with unparalleled functionality, speed, and responsiveness.
	Foundation HTML5 Animation with JavaScript covers everything that you need to know to create dynamic scripted animation using the HTML5 canvas.

About the author

Joe Lennon is a Web and Mobile applications developer from Cork, Ireland. He works as Product Manager of Mobile Solutions for Core International, one of the UK and Ireland’s leading enterprise HR software vendors. Joe is the author of Beginning CouchDB, and is co-author of the forthcoming title HTML5 in Action. He is also a regular contributor to the IBM developerWorks library. You can learn more about Joe and his work on his website at http://www.joelennon.ie.

Learning proper Drupal module development can take some time, but if you’re hacking together your first site and tinkering with modules you’ve downloaded, there are a few things that will help you move a lot quicker.

Hooks: Drupal’s secret sauce

First off, you’ll need to know what hooks are. People who are familiar with event driven or aspect oriented programming might recognize the hook system. It’s a way for a module to say, “I’ve gotten to this point in processing, does anyone want to do something before I go further?” Beginning Drupal has a good chapter that covers Drupal hooks.

The module announces this by calling module_implements, module_invoke, or module_invoke all, passing in the name of the hook as the first parameter; for example, module_invoke_all(‘user_logout’, $user).

Other modules can “hook in” and have their code run at that point in code execution by creating a function, called a hook implementation, that uses a particular naming convention. The naming convention is the implementing module’s name followed by the hook_name; for example, if your module were named “foo”, foo_user_logout would do something anytime a user logs out.

Developing from the command line

Using the command line can really speed up your development. With the Drush project, you can do things like download and enable modules, clear the cache, or reinstall your site directly from the command line. Other modules can also provide Drush commands, so check the full list of commands by typing “drush”, and Foundation Drupal 7 has an entire appendix devoted to drush.

Finding bugs

The Devel module suite has a bunch of great tools for developers (see Drupal 7 Module Development for more details). When the Devel module is enabled, you can debug with functions like:

• dpm which prints a variable to the screen in an easy to read way using the Krumo library.
• dd which outputs the variable to a file in the temp directory instead of to the screen.
• dargs which prints the arguments passed to the current function. This can be especially helpful to see what arguments are passed to a hook implementation.

This post should help you get started developing and debugging in Drupal.

Safari Books Online has the content you need

Take a look at some great Drupal resources in Safari Books Online:

	The Definitive Guide to Drupal covers every aspect of Drupal, from planning a successful project to making a living from designing Drupal sites, and even to contributing to the Drupal community yourself.
	Drupal 7 First Look is written for site administrators, themers, and developers who have some experience with Drupal 6 and want to upgrade their sites, themes, or modules to Drupal 7.
	Pro Drupal 7 Development is updated for Drupal 7, covering new essential APIs and improvements in Drupal 7, and teaches you how to write modules ranging from the simple to the complex.

About this author

Lin Clark is a Drupal developer specializing in Linked Data. She contributed to the RDF in Drupal 7 core initiative, created SPARQL Views as part of the 2010 Google Summer of Code, and has spoken extensively about the benefits of using Linked Data technologies in everyday applications. She attended Carnegie Mellon University and is currently pursuing a research Master’s at the Digital Enterprise Research Institute at NUI Galway. More information is available at lin-clark.com.

Nikravan spoke to Safari Books Online CEO Andrew Savikas and Nuance University’s Global Learning & Career Development Director Juli Rochon to get the latest info on the state-of-the-art of digital learning. From Nikravan’s article:

According to Savikas and Rochon, digital learning moves at the speed of creativity, a feature formal learning lacks. It supports engagement, imagination, inquiry-based learning and differentiated instruction, which can help develop sharper learners, faster.

Is HTML5 a W3C specification buzzword, or is it a term used to describe a host of technologies such as CSS3, JavaScript APIs, WebGL and more? For me, HTML5 is exactly as James Pearce puts it: it’s a badge or a logo for the way the Web is changing. The specification itself is getting closer to being finalized; however, new related specifications and ideas continue to make the Web a development platform for all types of applications. These ideas are breaking down the walls that currently prevent Web developers from building brilliant applications that work on all browsers and devices. There is more work ahead to make this happen, but progress is being made.

In light of these HTML5 specification changes, this post will focus on the topics that are of relevance for creating HTML5 mobile Web applications, which promises to be a big breakthrough trend in the coming year.

Tapping into device features using Device APIs

Ever since the explosion in popularity of mobile applications or “apps,” there has been an ongoing debate between developers about which development approach is better: native or Web. One of the largest pitfalls of the Web approach has been that the access to device features such as the camera, contacts and sensors, has been pretty much non-existent on most popular devices. In 2011, the W3C published a number of public working drafts for API specifications that define how devices and browsers should allow access to such features. Let’s take a brief look at some of these features now.

Battery Status API

This API exposes information about the current status of the device’s battery to Web applications. Using the API, applications can check the battery level, determine if the device is being charged, and find out how long before the battery is fully charged (if charging) or discharged (if not charging). The API also exposes several events, which can notify the application when the device has been plugged in or out of a power source, when the level of battery remaining has changed, or when the time remaining for charging/discharging has changed. Using this API, applications can adapt the way they work, depending upon the condition of the battery, thus using less power when the battery is running low.

Contacts API

The Contacts API gives Web applications read access to a device’s address book. The API standardizes a series of asynchronous methods and object properties that can be used to search the address book and read information about contacts such as name, phone numbers, email addresses and more.

Media Capture API

One of the missing features from mobile Web applications that I most often hear complaints about is access to the camera (and to a lesser extent, the microphone). The Media Capture API defines enhancements to the HTML file input type. This allows developers to specify how the field should capture data using a source other than the file system, such as the camera, video camera (camcorder) or microphone. A separate specification is being worked on to allow developers programmatic access to these input sources.

Messaging API

The Messaging API provides access to the device’s messaging functionality: SMS, MMS and e-mail. It exposes an asynchronous method for sending messages with or without attachments using the sms:, mms: and mailto: URI schemes. This will make it possible for users to send messages from a Web application without launching a separate application.

Network Information API

This API exposes connectivity information, which allows developers to detect what type of network connection the device is using: Ethernet, Wi-Fi, 2G, 3G, 4G or none. This API is designed to supplement the Offline Applications section of the HTML5 specification, which includes events that fire when the device changes network status from online to offline or vice-versa.

Sensor API

This is a relatively new API that exposes a standard series of methods and events for retrieving raw data from the various sensors available on the user’s device. Some of the sensors this may cover include temperature, ambient light, ambient noise, magnetic field, proximity, accelerometer, gyroscope and compass.

Vibration API

The Vibration API allows developers to provide tactile feedback to users of their applications in the form of a pulse or vibration. This is a widespread feature on mobile phones, typically used to alert the user to incoming calls and messages when the device is in silent mode. The API has various potential uses. It could be used to give feedback to the user if there is an input error on a form, or it could indicate negative actions (such as being hit) in a game.

Web Notifications API

The Web Notifications API defines a means of creating simple notifications that can be used to notify users of application events that may require further action. An example is in a webmail application, where a new mail has arrived. In this instance, the application should unobtrusively inform the user that they have new mail. If the user wishes to view this new message, they should be able to click (or tap, in the case of a mobile device) on the alert and it will bring them to the message. Otherwise, they should be able to ignore the message and continue what they are doing without any further action required on the notification itself. The Web Notifications API has been supported in Google Chrome since version 5, but has yet to be supported by any other browser. Because they are of particular usefulness in mobile Web applications, I am hopeful that this particular specification will gain traction in the mobile browser space in the coming year.

HTML5 Speech Input API

If you use the Google Chrome browser, you may have noticed recently that when you visit google.com, the search box has a microphone icon on the right-hand-side. If your computer has a microphone, you can speak your search query rather than type it, and Google will go and fetch the search results automatically (Figure 1).

Figure 1. Google Speech Input in action

With Apple’s breakthrough in speech recognition with its Siri feature on iPhone 4S, and with Google’s speech search functionality, 2012 looks like it will be a big year for speech input, putting the HTML5 Speech Input API in the spotlight.

All of the HTML5 mobile APIs mentioned here are worth keeping an eye on, since they will have a big impact on mobile Web application development going forward.

Safari Books Online has the content you need

To get started developing HTML5 mobile apps, take a look at the following titles that are in Safari Books Online.

	Head First Mobile Web puts your JavaScript, CSS, and HTML5 skills to work, optimizing your site to perform its best in the demanding mobile market.
	Sams Teach Yourself HTML5 Mobile Application Development in 24 Hours provides you with step-by-step instructions, guiding you through the most common HTML5 mobile development tasks.
	Mobile Web Design For Dummies® is the practical guide to go to if you’re contemplating Web design in a mobile world.
	Pro jQuery Mobile will teach you how to create responsive, native-looking applications for iOS, Android, Windows Phone and Blackberry.
	The Programming the Mobile Web will teach you the intricacies and pitfalls involved in building HTML and CSS-based mobile apps to work with the iPhone, Android devices, and other smartphones.

About this author

Joe Lennon is a Web and Mobile applications developer from Cork, Ireland. He works as Product Manager of Mobile Solutions for Core International, one of the UK and Ireland’s leading enterprise HR software vendors. Joe is the author of Beginning CouchDB, and is co-author of the forthcoming title HTML5 in Action. He is also a regular contributor to the IBM developerWorks library. You can learn more about Joe and his work on his website at http://www.joelennon.ie.

Drupal has gained popularity as the open source CMS for enterprise, powering sites for clients from Twitter to the White House. With its large and highly interactive developer community, it’s a hot bed of lead user innovation.

This has lead to a unique problem—developers have too many job offers. As Drupal founder Dries Buytaert says, “the demand for Drupal talent exceeds the supply … most of the Drupal developers I know are maxed out.” This makes it a great time to learn Drupal.

Skilling up in Drupal

The Drupal skills that are most in demand are site building, theming, and module development, and there are a ton of resources available here on Safari Books Online to get started in all three of those roles.

Site builders piece sites together by downloading and configuring modules (which are called plugins in other systems). This requires getting to know the most popular modules on Drupal.org, as well as hidden gems, and a knack for experimentation. The book Using Drupal (Drupal 7 version available as a Rough Cut) walks you through your first site building projects, and the new Drupal User’s Guide provides a lot of the extra know-how about site planning and information architecture that site builders need.

Themers turn the generic Drupal output into a visual masterpiece using CSS and JavaScript, and sometimes customizing the templates using HTML and the occasional bit of PHP. A great book to start with theming is Front End Drupal, even though it’s only available for Drupal 6. There are also three chapters on theming for Drupal 7 in the Definitive Guide to Drupal.

Module developers create new kinds of functionality for site builders to play with, making heavy use of PHP and Drupal’s native APIs, as well as integrating with 3^rd party APIs. Drupal 7 Module Development gives you tips on how to use those APIs from some of the people who wrote them. Pro Drupal Development, for years the bible of Drupal developers, also has a Drupal 7 version available.

Get paid to level up with Acquia U

The demand for good Drupal talent is so high that one company, Acquia, is actually paying recent and imminent college grads to get trained. The company, started by Drupal’s founder, partners with Drupal companies to provide enterprise support, but many of those companies are strapped to find Drupal developers. So Acquia decided to step in and infuse the developer market with new talent.

Acquia U gives you 6 weeks of paid training and then three 6 week paid rotations through their technical teams. Applications are being accepted now for the program.

Increasing your Drupal scorecard

While there is no certification program for Drupal, the community has its own informal metric in the form of Certified to Rock, which tries to calculate community involvement for the top 24,000 Drupal contributors. The site’s creators make clear that the way to increase your CTR score is simple: get more involved in contributing to Drupal. But besides just uping your CTR score, community involvement also increases your visibility and value to potential employers.

One great way to increase your rockstar quotient is to get involved in core development. A good place to start is Drupal 8’s core initiatives. These initiatives provide signposts as to where Drupal is heading over the next few years and they also help new contributors find relevant issues. Let’s take a look at these initiatives to see which areas of Drupal are the best fit for you.

Mobile Initiative

With a billion-plus phones sold per year, the Web dev community is readjusting their sights (and sites) to focus on mobile, which is why the Mobile Initiative is making Drupal 8 a first-class mobile platform. This initiative, led by Drupal 7 Module Development co-author John Albin Wilkins, is perfect for those who “geek out” about touch screen interaction and responsive design.

HTML5 and Design Initiatives

The HTML5 initiative is rewriting Drupal’s templates to take advantage of the new HTML tags, such as <article> and <time>, and new form elements and input types. Lead by Jacine Luisi, co-author of the Definitive Guide to Drupal 7, the initiative is a great way to get involved if you have a passion for markup. If you’re into design and theming but don’t care as much about the ins and outs of the ever changing HTML5 specification, there is the Design Initiative.

Web Services and Configuration Management initiatives

The Web Services and Configuration Management initiatives, lead by Drupal 7 Module Development co-authors Larry Garfield and Greg Dunlap respectively, are both great places for hard-core PHP backend ninjas to dig in. Web Services aims to make Drupal an effective REST server. Configuration Management is working on making configuration easier to revision, so that it can be rolled back easily, and it is easier to deploy to multiple servers.

Multilingual Initiative

The Multilingual Initiative continues Drupal 6’s emphasis on internationalization, making Drupal the best solution not just for English language sites but also for the 100+ languages into which the community is translating Drupal.

Find out more information about all initiatives and become a Drupal core developer. With the help of Safari Books Online and the sites mentioned in this post you will be well on your way to gaining the skills you need to become a Drupal developer.

If you’re ready to take the next step, look for some upcoming Drupal tips from Lin Clark.

Safari Books Online has the content you need

You’ll find a lot of good Drupal resources on Safari Books Online. Here are a few to get you started.

	With the recipes in Using Drupal, you’ll take full advantage of the vast collection of community-contributed modules that make the Drupal web framework useful and unique.
	Drupal User’s Guide shows how to use Drupal 7’s newest improvements to build more modern, manageable sites for any business or organization. Hogbin covers crucial topics other Drupal books ignore, including search engine optimization and accessibility.
	Front End Drupal is 100% focused on issues of site design, behavior, usability, and management. The authors show how to style Drupal sites, make the most of Drupal’s powerful templating system, build sophisticated community sites, streamline site management, and build more portable, flexible themes.
	The Definitive Guide to Drupal 7 is the most comprehensive book for getting sites done using the powerful and extensible Drupal content management system. Written by a panel of expert authors, the book covers every aspect of Drupal, from planning a successful project all the way up to making a living from designing Drupal sites and to contributing to the Drupal community yourself.
	In Drupal 7 Module development , six professional Drupal developers use a practical, example-based approach to introduce PHP developers to the powerful new Drupal 7 tools, APIs, and strategies for writing custom Drupal code.
	Pro Drupal 7 Development updates the most popular development reference for the newest major release of Drupal. With several new and completely-rewritten essential APIs and improvements in Drupal 7, this book will not only teach developers how to write modules ranging from simple to complex, as well as learn how Drupal itself works.

About this author

Lin Clark is a Drupal developer specializing in Linked Data. She contributed to the RDF in Drupal 7 core initiative, created SPARQL Views as part of the 2010 Google Summer of Code, and has spoken extensively about the benefits of using Linked Data technologies in everyday applications. She attended Carnegie Mellon University and is currently pursuing a research Master’s at the Digital Enterprise Research Institute at NUI Galway. More information is available at lin-clark.com.

This 60-minute webcast is for IT executives, architects, and developers alike, as world-renowned expert David Linthicum explains why the days of managing IT organizations as private fortresses will rapidly disappear as IT inevitably becomes a global community. He demonstrates how to run IT when critical elements of customer, product, and business data and processes extend far beyond the firewall—how to use all that information to deliver real-time answers about everything from an individual customer’s credit to the location of a specific cargo container.

David is the author of Cloud Computing and SOA Convergence in Your Enterprise: A Step-by-Step Guide from Addison-Wesley Professional. Watch  his informative SOA webcast now or browse through our entire archive of free Safari Books Online webcasts.