Welcome!

Machine Learning Authors: Elizabeth White, Liz McMillan, Jack Jachner, Pat Romanski, Progress Blog

Related Topics: Machine Learning

Machine Learning : Article

Real-World AJAX Book Preview: Design of Mobile AJAX Applications

Real-World AJAX Book Preview: Design of Mobile AJAX Applications

This content is reprinted from Real-World AJAX: Secrets of the Masters published by SYS-CON Books. To order the entire book now along with companion DVDs for the special pre-order price, click here for more information. Aimed at everyone from enterprise developers to self-taught scripters, Real-World AJAX: Secrets of the Masters is the perfect book for anyone who wants to start developing AJAX applications.

Design of Mobile AJAX Applications
Having discussed the resurgence of browser-based applications and the significance of AJAX widgets on mobile devices, we'll turn to the design of AJAX applications/widgets.

Traditionally, standards on the mobile Internet were driven by OMA, the Open Mobile Alliance (www.openmobilealliance.com). With AJAX and Web 2.0, for the first time we're seriously entertaining the possibility of the "One Web," a seamless Web spanning multiple devices and delivering the same information regardless of the device that's used to access it.

As might be expected, the One Web concept is driven by the Internet as opposed to the mobile Internet. The standards bodies governing the idea of One Web are the same as the Internet standardization bodies like W3C (www.w3.org/). W3C is working with other bodies like OMA to deliver a consistent set of One Web recommendations.

Per the W3C documentation, One Web means making, as far as is reasonable, the same information and services available to users regardless of the device they're using. However, it doesn't mean that exactly the same information is available in exactly the same way across all devices. Some services and information are more suitable to and targeted at particular user contexts.

In W3C, the W3C mobile Web initiative (www.w3.org/2005/MWI/Activity) and the Mobile Web Best Practice (MWBP) Working Group (www.w3.org/2005/01/BPWGCharter/Overview.html) are working towards the One Web goal. While some of the standards and guidelines produced by this group are still under discussion, they provide a good basis to design a mobile browsing application and by extension a mobile AJAX application.

The mission of the MWBP Working Group is to develop a set of technical best practices and associated materials in support of developing Web sites that provide an appropriate user experience on mobile devices.

The working group aims to extend the reach of the Web to mobile devices by providing guidelines, checklists, and best practice statements that are easy to comprehend and implement. When implemented by a Web site provider, they will enable users to get the content on mobile devices, particularly small-screen devices such as PDAs, smart phones, and touch-screen devices.

The working group expects to maintain contact with groups such as the Open Mobile Alliance.

Besides creating recommendations and best practices for the One Web, W3C is also working towards the concept of a Mobile OK trustmark. According to W3C the trustmark will serve as the main conformance claim for the best practices document.

By definition, mobile AJAX applications are mobile Web applications. The impact of the preceding discussion is that when we consider the design of mobile AJAX applications, we have to consider it in two facets: the design of a mobile Web site as recommended by the W3C and AJAX-specific considerations as applicable to mobile devices.

To design mobile AJAX applications, we first have to understand W3C's standardization efforts and then the specific factors relating to mobile AJAX.

Also note that the W3C recommendations discussed here pertain only to site usability. In a broader context, usability can be defined as comprising three parts, namely, site usability, device usability, and browser usability. According to W3C definitions:

Site Usability relates to the structure, content, and layout rules of a site and is a measure of the effectiveness of the mobile Web site.

Device Usability pertains to the capability of the equipment being used easily and effectively.

Browser Usability defines the ease of using a browser effectively and doing the functions of reading, navigating, and interacting. The ease of interaction, page rendering, and caching are issues that are frequently used to judge browser usability. Device usability is determined by the device maker and browser usability is defined by the vendor creating the browser.

Factors Affecting the Design of Mobile Browsing Applications
The factors affecting the design of mobile browsing applications are:

Presentation Issues: Because Web pages are created to be displayed on desktops, they can't be presented directly on the mobile device in their original form. Not only is the overall user experience poor, but the content doesn't lay out as originally intended due to the different screen size.

Input: Mobile devices have limited input capacity and it's hard to type in long URLs. In some cases, there's no pointing device, as in some phones, and in general, it's hard to recover from errors.

Bandwidth and Cost: Mobile networks can be slower than fixed line networks. They have a higher latency and in most cases the user pays for data retrieval. The device may support limited types of content. The user may download content only to realize that she can't use it. The user may download content and have to pay for additional data such as advertising. All these factors degrade the user experience and usability.

User Goals: Unlike Web users, mobile users, have a definite purpose when they browse. Web users browse for fun or to explore a topic without a specific goal. The mobile user seeks a specific piece of information and wants it delivered in a format suitable for the device, in other words, a short/exact response to the information request that can be rendered on the target device.

Advertising: It's necessary to be extra vigilant when it comes to ads on the mobile Internet because they can potentially hinder the user experience and may not be free because the user pays for the data download charges.

Device Limitations: Mobile devices impose limits due to screen size and limited input capabilities. There are other limitations from the restrictions on the software that can be executed on a device. In practice, this means browsers can support limited or no plug-in or scripting capabilities

Some activities associated with rendering Web pages are computationally intensive. For example, reflowing pages, laying out tables, processing unnecessarily long and complex stylesheets, and handling invalid mark-up. Such compute-intensive applications push the capabilities of the battery, memory, and communications.

General Design Principles
Establish the Context of the Device: It's necessary to take all reasonable steps to find the capabilities of the target device so that the content can be served to the device in the most suitable form. The techniques used to find the capabilities of a device are beyond our scope but they include CC/PP or Composite Capability/Preference Profiles (www.w3.org/TR/CCPP-struct-vocab/), UAProf or User Agent Profile (www.openmobilealliance.com), CSS Media queries (www.w3.org/TR/css3-mediaqueries/), DDWG output (www.w3.org/2005/01/DDWGCharter/), and DIWG material (http://globalchange.gov/policies/diwg/diwg-summary.html). When insufficient information is available, reasonable defaults should be used.

Exploit Client Capabilities and Don't Take the Least Common Denominator Approach: If a better user experience can be obtained by using the device's capabilities, the W3C recommends that the developer exploit such capabilities.

Work Around Deficient Implementations: The developer should take reasonable steps to work around deficient implementations. Because the software in mobile devices is frequently embedded in the device, there's no easy way to correct or enhance software once it's in the field. So some browser implementations will have known limitations and the developer should cater to them as best he can.

Content Adaptation
Devices can differ in terms of mark-up, image format, image size, and color depth. Hence content has to be adapted so it can best be rendered on the device. The process of altering content to cater to the widely varying characteristics of mobile devices is called content adaptation. Content adaptation is a complex process and its full scope won't be covered here.

In the easiest cases adaptation can be simple and consist of just determining the device type and then choosing content from among a set of previously prepared content appropriate to the device characteristics.

The other extreme involves dynamic content adaptation with the actual content formatted at the time of image retrieval. The adaptation itself can be carried out at three different points: server-side content adaptation, network adaptation, and client-side content adaptation. Currently W3C documents cover only server-side content adaptation.

From a design perspective, the content adaptation section of the W3C recommendation is interesting because it gives us the default delivery context, which represents the least common denominator when sufficient information isn't known to do content adaptation.

The default delivery context is defined as follows:

This content is reprinted from Real-World AJAX: Secrets of the Masters published by SYS-CON Books. To order the entire book now along with companion DVDs, click here to order.

More Stories By Ajit Jaokar

Ajit Jaokar is the author of the book 'Mobile Web 2.0' and is also a member of the Web2.0 workgroup. Currently, he plays an advisory role to a number of mobile start-ups in the UK and Scandinavia. He also works with the government and trade missions of a number of countries including South Korea and Ireland. He is a regular speaker at SYS-CON events including AJAXWorld Conference & Expo.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@CloudExpo Stories
Blockchain is a shared, secure record of exchange that establishes trust, accountability and transparency across business networks. Supported by the Linux Foundation's open source, open-standards based Hyperledger Project, Blockchain has the potential to improve regulatory compliance, reduce cost as well as advance trade. Are you curious about how Blockchain is built for business? In her session at 21st Cloud Expo, René Bostic, Technical VP of the IBM Cloud Unit in North America, will discuss th...
The question before companies today is not whether to become intelligent, it’s a question of how and how fast. The key is to adopt and deploy an intelligent application strategy while simultaneously preparing to scale that intelligence. In her session at 21st Cloud Expo, Sangeeta Chakraborty, Chief Customer Officer at Ayasdi, will provide a tactical framework to become a truly intelligent enterprise, including how to identify the right applications for AI, how to build a Center of Excellence to ...
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
While some vendors scramble to create and sell you a fancy solution for monitoring your spanking new Amazon Lambdas, hear how you can do it on the cheap using just built-in Java APIs yourself. By exploiting a little-known fact that Lambdas aren’t exactly single-threaded, you can effectively identify hot spots in your serverless code. In his session at @DevOpsSummit at 21st Cloud Expo, Dave Martin, Product owner at CA Technologies, will give a live demonstration and code walkthrough, showing how ...
As DevOps methodologies expand their reach across the enterprise, organizations face the daunting challenge of adapting related cloud strategies to ensure optimal alignment, from managing complexity to ensuring proper governance. How can culture, automation, legacy apps and even budget be reexamined to enable this ongoing shift within the modern software factory?
SYS-CON Events announced today that Elastifile will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Elastifile Cloud File System (ECFS) is software-defined data infrastructure designed for seamless and efficient management of dynamic workloads across heterogeneous environments. Elastifile provides the architecture needed to optimize your hybrid cloud environment, by facilitating efficient...
There is only one world-class Cloud event on earth, and that is Cloud Expo – which returns to Silicon Valley for the 21st Cloud Expo at the Santa Clara Convention Center, October 31 - November 2, 2017. Every Global 2000 enterprise in the world is now integrating cloud computing in some form into its IT development and operations. Midsize and small businesses are also migrating to the cloud in increasing numbers. Companies are each developing their unique mix of cloud technologies and service...
@DevOpsSummit at Cloud Expo taking place Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center, Santa Clara, CA, is co-located with the 21st International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is ...
SYS-CON Events announced today that Golden Gate University will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Since 1901, non-profit Golden Gate University (GGU) has been helping adults achieve their professional goals by providing high quality, practice-based undergraduate and graduate educational programs in law, taxation, business and related professions. Many of its courses are taug...
DevOps at Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to w...
With Cloud Foundry you can easily deploy and use apps utilizing websocket technology, but not everybody realizes that scaling them out is not that trivial. In his session at 21st Cloud Expo, Roman Swoszowski, CTO and VP, Cloud Foundry Services, at Grape Up, will show you an example of how to deal with this issue. He will demonstrate a cloud-native Spring Boot app running in Cloud Foundry and communicating with clients over websocket protocol that can be easily scaled horizontally and coordinate...
SYS-CON Events announced today that DXWorldExpo has been named “Global Sponsor” of SYS-CON's 21st International Cloud Expo, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Digital Transformation is the key issue driving the global enterprise IT business. Digital Transformation is most prominent among Global 2000 enterprises and government institutions.
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emergi...
From 2013, NTT Communications has been providing cPaaS service, SkyWay. Its customer’s expectations for leveraging WebRTC technology are not only typical real-time communication use cases such as Web conference, remote education, but also IoT use cases such as remote camera monitoring, smart-glass, and robotic. Because of this, NTT Communications has numerous IoT business use-cases that its customers are developing on top of PaaS. WebRTC will lead IoT businesses to be more innovative and address...
21st International Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy. Me...
In his session at 20th Cloud Expo, Scott Davis, CTO of Embotics, discussed how automation can provide the dynamic management required to cost-effectively deliver microservices and container solutions at scale. He also discussed how flexible automation is the key to effectively bridging and seamlessly coordinating both IT and developer needs for component orchestration across disparate clouds – an increasingly important requirement at today’s multi-cloud enterprise.
DevOps at Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to w...
Vulnerability management is vital for large companies that need to secure containers across thousands of hosts, but many struggle to understand how exposed they are when they discover a new high security vulnerability. In his session at 21st Cloud Expo, John Morello, CTO of Twistlock, will address this pressing concern by introducing the concept of the “Vulnerability Risk Tree API,” which brings all the data together in a simple REST endpoint, allowing companies to easily grasp the severity of t...
Recently, WebRTC has a lot of eyes from market. The use cases of WebRTC are expanding - video chat, online education, online health care etc. Not only for human-to-human communication, but also IoT use cases such as machine to human use cases can be seen recently. One of the typical use-case is remote camera monitoring. With WebRTC, people can have interoperability and flexibility for deploying monitoring service. However, the benefit of WebRTC for IoT is not only its convenience and interopera...
Any startup has to have a clear go –to-market strategy from the beginning. Similarly, any data science project has to have a go to production strategy from its first days, so it could go beyond proof-of-concept. Machine learning and artificial intelligence in production would result in hundreds of training pipelines and machine learning models that are continuously revised by teams of data scientists and seamlessly connected with web applications for tenants and users.