Markku Laine

Toward Unified Web Application Development

Web application development in the context of the conventional three-tier architecture is complex, typically requiring a team of experts. Recent Web application architectures and frameworks simplify the development process, potentially turning tier-specific experts into one-person developer teams.

Leveraging declarative languages in web application development

Web Applications have become an omnipresent part of our daily lives. They are easy to use, but hard to develop. WYSIWYG editors, form builders, mashup editors, and markup authoring tools ease the development of Web Applications. However, more advanced Web Applications require servers-side programming, which is beyond the skills of end-user developers. In this paper, we discuss how declarative languages can simplify Web Application development and empower end-users as Web developers. We first identify nine end-user Web Application development levels ranging from simple visual customization to advanced three-tier programming. Then, we propose expanding the presentation tier to support all aspects of Web Application development. We introduce a unified XForms-based framework—called XFormsDB—that supports both client-side and server-side Web Application development. Furthermore, we make a language extension proposal—called XFormsRTC—for adding true real-time communication capabilities to XForms. We also present XFormsDB Integrated Development Environment (XIDE), which assists end-users in authoring highly interactive data-driven Web Applications. XIDE supports all Web Application development levels and, especially, promotes the transition from markup authoring and snippet programming to single and unified language programming.

Extending XForms with server-side functionality

Most Web applications are based on a conventional three-tier architecture, in which the presentation, application logic, and data management are developed and maintained in separate tiers. The main disadvantage of this architecture is that it requires expertise in multiple programming languages, programming paradigms, and data models used in each tier. A single expert rarely masters all technologies involved. In this paper, we introduce a framework that allows users---namely, Web designers---to implement entire Web applications using only markup languages. In addition, all application development is performed on the client side, simplifying both development and maintenance work. The proposed framework is based on the XForms markup language and its server-side extension proposed in this paper. We derive the extension requirements from the literature and depict its function using a simple Web-based blog application. We also show how the extension can be implemented as part of a comprehensive Web application development framework called XFormsDB. Our conclusion is that expanding the presentation tier to define both application logic and data management functionality makes both the development and maintenance of small- and medium-sized Web applications easier.

TouchModifier: enriched multi-touch gestures for tablet browsers

Touch-based web browsing with tablet devices is not yet utilizing its full potential. This paper introduces an asymmetric bimanual interaction technique that makes browser-based multi-touch gestures more expressive. In the proposed TouchModifier technique, a semi-transparent panel with modifier controls is docked to the side of the screen. The non-dominant hand operates the side panel, while the dominant hand interacts with the application content as usual. The controls on the side panel operate as fluid mode selectors that enrich and override the semantics of the dominant hand gestures. This opens novel interaction possibilities in browser applications, while remaining interoperable with existing web pages. In this paper, we describe the proposed concept and present its prototype implementation with a use case.

XFormsDB: a declarative web application framework

Most Web applications utilize a three-tier architecture, in which the presentation, application logic, and data management are implemented as separate tiers. The disadvantage of this popular approach is that it usually requires expertise in multiple programming languages and paradigms as well as data models used in each tier. A single expert rarely masters all the technologies involved. In this demonstration, we give an overview of the XFormsDB framework that allows developers to implement entire Web applications using only markup languages. The framework is based on the XForms markup language and our server-side extensions. We demonstrate the functionality of the framework using a simple blog application as an example.

XFormsDB: an extensible web application framework built upon declarative W3C standards

Most Web applications are based on a conventional three-tier architecture, in which the presentation, application logic, and data management are developed and maintained in separate tiers. The main disadvantage of this architecture is that it requires expertise in multiple programming languages, programming paradigms, and data models used in each tier. A single expert rarely masters all the technologies and concepts involved. In this paper, we introduce a tier-expanding architectural approach that unifies the client-side (presentation tier) and server-side (logic and data tiers) programming under a single model. We base our approach on a W3C-standardized client-side markup language, XForms, and its server-side extension proposed in this paper. We derive the extension requirements from the literature and use cases, and demonstrate their functionality on the example of a blog Web application. We also show how the extension can be implemented as part of a comprehensive Web application framework called XFormsDB. The XFormsDB framework is an extensible Web application framework built upon declarative W3C standards. It has four major advantages: (1) one programming language, (2) one data model, (3) based on W3C-standardized declarative markup, and (4) extensibility in all tiers. Our conclusion is that expanding the presentation tier to cover both application logic and data management functionality makes both the development and maintenance of small- and medium-sized Web applications easier.

Aalto Interface Metrics (AIM): A Service and Codebase for Computational GUI Evaluation

Aalto Interface Metrics (AIM) pools several empirically validated models and metrics of user perception and attention into an easy-to-use online service for the evaluation of graphical user interface (GUI) designs. Users input a GUI design via URL, and select from a list of 17 different metrics covering aspects ranging from visual clutter to visual learnability. AIM presents detailed breakdowns, visualizations, and statistical comparisons, enabling designers and practitioners to detect shortcomings and possible improvements. The web service and code repository are available at interfacemetrics.aalto.fi.

UniQue: An Approach for Unified and Efficient Querying of Heterogeneous Web Data Sources

Governments, organizations, and people are publishing open data on the Web more than ever before. To consume the data, however, requires substantial effort from web mashup developers, as they have to familiarize themselves with a diversity of data formats and query techniques specific to each data source. While several solutions have been proposed to improve web querying, none of them covers aforementioned aspects in a developer friendly and efficient manner. Therefore, we devised a unified querying (UniQue) approach and a proxy-based implementation that provides a uniform and declarative interface for querying heterogeneous data sources across the Web. Besides hiding the differences between the underlying data formats and query techniques, UniQue heavily embraces open W3C standards to minimize the learning effort required by developers. Pursuing this further, we propose Unified Query Language (UQL) that combines the expressiveness of CSS Selectors and XPath into a single and flexible selector language. We show that the adoption of UniQue and UQL can effectively streamline web querying, leverage developers’ existing knowledge, and reduce generated network traffic compared to the current state-of-the-art approach.