XML is becoming one of the most influential standards concerning data exchange and Web-presentations. In this paper we present a visual language for querying and transforming XML data. The language is based on a visual document metaphor and the notion of document patterns. It combines an intuitive, dynamic form-based interface for defining queries and transformation rules with powerful pattern matching capabilities and offers thus a highly expressive yet easy to use visual language. Providing visual language support for XML not only helps end users, it is also a big opportunity for the VL community to receive greater attention. 1 Introduction The eXtensible Markup Language (XML) is a standardized notation for documents and other data [3]. It is very likely that XML develops into the prevailing format for exchanging documents and presenting data in the WorldWide Web. An XML document contains, in addition to its content, information about its structure, which is achieved through tagge...

We present a visual language for querying and transforming XML data. The language is based on a visual document metaphor and the notion of document patterns and rules. It combines a dynamic form-based interface for defining queries and transformation rules with powerful pattern matching capabilities and offers thus a highly expressive visual language. The design of the visual language is specifically targeted at end users.

This article describes emerging research into how visual programming languages may lead to and even require the development of new software engineering support paradigms. Keywords: visual programming languages, software engineering, end-user programming, end-user software engineering, Forms/3. 1. Introduction Visual programming languages (VPLs) are becoming increasingly common in several domains. For example, visual programming languages or sublanguages are becoming the most common way to do some kinds of GUI programming, are becoming the most common way of specifying visualization graphics depicting scientific data, and are also starting to appear as macro generators for end-user applications. However, despite the increase in the use of VPLs for these and other programming tasks, there has been almost no attention to software engineering support mechanisms when working in these languages. Visual programming is programming in which

Software engineering research and programming language design have enjoyed a symbiotic relationship, with traceable impacts since the 1970s, when these areas were first distinguished from one another. This report documents this relationship by focusing on several major features of current programming languages: data and procedural abstraction, types, concurrency, exceptions, and visual programming mechanisms. The influences are determined by tracing references in publications in both fields, obtaining oral histories from language designers delineating influences on them, and tracking cotemporal research trends and ideas as demonstrated by workshop topics, special issue publications, and invited talks in the two fields. In some cases there is conclusive This article has been developed under the auspices of the Impact Project. The aim of the project is to provide a scholarly study of the impact that software engineering research—both academic and industrial—has had upon practice. The principal output of the project is a series of individual papers covering the impact upon practice of research in several selected major areas of software

We propose a form-based interface to expresses XML queries and transformations by so-called "document patterns" that describe properties of the requested information and optionally specify how the found results should be reformatted or restructured. The interface is targeted at casual users who want a fast and easy way to find information in XML data resources. By using dynamic forms an intuitive and easy-to-use interface is obtained that can be used to solve a wide spectrum of tasks, ranging from simple selections and projections to advanced data restructuring tasks. The interface is especially suited for end users since it can be used without having to learn a programming or query language and without knowing anything about (query or XML) language syntax, DTDs or schemas. Nevertheless, DTDs can be well exploited, in particular, on the user interface level to support the semi-automatic construction of queries.

End-user development has enormous potential to make computers more useful in a large variety of contexts by providing people without any formal programming training increased control over information processing tasks. This variety of contexts poses a challenge to end-user development system designers. No individual system can hope to address all of these challenges. The field of enduser development is likely to produce a plethora of systems fitting specific needs of computer end-users. The goal of this chapter is not to advocate a kind of universal end-user development system, but to cut across a variety of application domains based on our experience with the AgentSheets end-user simulation-authoring tool. We have pioneered a number of programming paradigms, experienced a slew of challenges originating in different user communities, and evolved end-user development mechanisms over several years. In this chapter we present design guidelines that cut across this vast design space by conceptualizing the process of end-user development as a learning experience. Fundamentally, we claim that every end-user development system should attempt to keep the learning challenges in proportion to the skills end-users have. By adopting this perspective, end-user development can actively scaffold a process during which end-users pick up new end-user development tools and gradually learn about new functionality. We structure these design guidelines in accordance to their syntactic, semantic and pragmatic nature of support offered to end-users.

Development environments based on ActiveX controls and JavaBeans are marketed as "visual programming" platforms; in practice their visual dimension is limited to the design and implementation of an application's graphical user interface (GUI. The availability of sophisticated GUI development environments and visual component development frameworks is now providing viable platforms for implementing visual programming within general-purpose platforms, i.e. for the specification of non-GUI program functionality using visual representations. We describe how specially-designed reflective components can be used in an industry-standard visual programming environment to graphically specify sophisticated data transformation pipelines that interact with GUI elements. The components are based on Unix-style filters repackaged as ActiveX controls. Their visual layout on the development environment canvas is used to specify the connection topology of the resultant pipeline. The process of converting filter-style programs as visual controls is automated using a domainspecific language. We demonstrate the approach through the design and the visual implementation of a GUI-based spelling checker.

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Existing spatiotemporal data models and query languages offer only basic support to query changes of data. In particular, although these systems often allow the formulation of queries that ask for changes at particular time points, they fall short of expressing queries for sequences of such changes. In this chapter we propose the concept of spatiotemporal patterns as a systematic and scalable concept to query developments of objects and their relationships. Based on our previous work on spatiotemporal predicates, we outline the design of spatiotemporal patterns as a query mechanism to characterize complex object behaviors in space and time. We will not present a fully-fledged design. Instead, we will focus on deriving constraints that will allow spatiotemporal patterns to become well-designed composable abstractions that can be smoothly integrated into spatiotemporal query languages. Spatiotemporal patterns can be applied in many different areas of science, for example, in geosciences, geophysics, meteorology, ecology, and environmental studies. Since users in these areas typically do not have extended formal computer training, it is often difficult for them to use advanced query languages. A visual notation for spatiotemporal patterns can help solving this problem. In particular, since spatial objects and their relationships have a natural graphical representation, a visual notation can express relationships in many cases implicitly where textual notations require the explicit application of operations and predicates. Based on our work on the visualization of spatiotemporal predicates, we will sketch the design of a visual language to formulate spatiotemporal patterns.

Analysts regularly wrangle data into a form suitable for computational tools through a tedious process that delays more substantive analysis. While interactive tools can assist data transformation, analysts must still conceptualize the desired output state, formulate a transformation strategy, and specify complex transforms. We present a model to proactively suggest data transforms which map input data to a relational format expected by analysis tools. To guide search through the space of transforms, we propose a metric that scores tables according to type homogeneity, sparsity and the presence of delimiters. When compared to “ideal ” hand-crafted transformations, our model suggests over half of the needed steps; in these cases the top-ranked suggestion is preferred 77 % of the time. User study results indicate that suggestions produced by our model can assist analysts ’ transformation tasks, but that users do not always value proactive assistance, instead preferring to maintain the initiative. We discuss some implications of these results for mixed-initiative interfaces. ACM Classification: H5.2 [Information interfaces and presentation]: User Interfaces – Graphical user interfaces. General terms: