Reprinted from American Laboratory September 2005 Creating Rich Web-Based LIMS With Programmable XML Technologies by Dinu Toiba Laboratory information management sys- Web-enabled solutions to the arrival Throughout the late 1980s and early tems convert mass amounts of data into of rich, scalable Web-based LIMS 1990s, client/server was an industry analytical information useful throughout applications. This technology is illus- buzzword, as applications were migrated the enterprise. Traditionally based on trated by the version 10 Web-based from centralized minicomputers and familiar client/server technology LIMS application (STARLIMS mainframes to networks of desktop deployed in a local area network/wide Corp., Hollywood, FL). computers.1 Client/server architecture area network (LAN/WAN) environ- requires software installation and updat- ment, these mission-critical computing ing on all clients and is generally limited systems have generally been isolated and Deployment options for to LAN or WAN environments. fully accessible only to users connected to the laboratory’s LIMS network. commercial LIMS Thin client—terminal In the rush to develop products that solutions services based deliver laboratory automation features Thick client—client/server To quickly deploy applications over through a Web browser interface, several the Web, many software developers, LIMS vendors added browser front ends applications LIMS vendors included, adopted the to existing products, offering Web- The familiar client/server model has terminal services approach—also enabled software. A number of these powered LIMS and most other enter- referred to as server-based computing. packages integrate HTML-based por- An example of this is Terminal tal-like features that allow data con- Services, in which all application sumers to prelog-in requests for test- execution, data processing, and ing, view sample status, and access XML and SOAP-based data storage take place on the reports. Other vendors offer server- server. Applications and user based options by employing emula- Web services are now desktops are displayed on clients tion technology such as Microsoft using terminal-emulation soft- Corp. (Redmond, WA) Windows™ Terminal Services (WTS) and Citrix allowing developers to ware. 2 The advantage of this approach for LIMS and other Systems, Inc. (Fort Lauderdale, FL) MetaFram® enabling LIMS deploy- provide the scalability enterprise system vendors was the ability to expand the reach of ment over the Web. and usability required by applications to user desktops and devices located throughout the Both of these methods focus on network or beyond it via the Web. extending the existing application complex systems such However, this approach requires reach, making LIMS accessible to upfront investments in robust enterprise clients. These approaches as LIMS. servers and uncompromised net- presented limited graphical user work availability. interfaces (GUIs), and in some cases complex configuration management, prise business and manufacturing sys- Thick client—Web-enabled with less than optimal response times. tems over the years. Impressive progress Shortcomings have fueled demand for in PC hardware and system technology applications true Web-based solutions purposely built has enabled comprehensive client-side Originally written for client/server to utilize advanced Internet technology computing with enhanced usability, ﬂex- environments, several LIMS products as their computing platform. A true ibility, and scalability. In client/server were modified to allow connectivity Web-based application delivers an LIMS architecture, the client processes through the Web. By replacing direct uncompromising “rich” user experience, the user interface and performs some or client–database connection (i.e., open together with unlimited enterprise reach. all of the application processing. Servers database connectivity [ODBC]) with maintain databases and process requests Web services protocols (i.e., simple This article examines currently avail- from clients to extract data or update object access protocol [SOAP]), remote able Internet deployment options and databases. A LIMS application server access to databases was made possible. illustrates the historical development provides additional business processing The advantages of this approach are of LIMS software from standard for clients. Servers and clients are con- accessibility to a central database from client/server technology through nected via a LAN or WAN. multiple sites and a familiar, rich user SOAP-based Web services. This tech- nical infrastructure is powered by the configurable LIMS business logic developed over 15 years by STAR- LIMS Corp. Key technical requirements for Web-based applications Version 10 was built to meet the fol- lowing technological requirements: • Rich, fully functional GUI leading to a rich user experience compara- ble to or better than client/server • Built to Internet standards, com- prising design norms users have grown accustomed to on the Web, to significantly decrease training duration and complexity • Zero client side installs, eliminat- ing the costly process of installing Figure 1 Evolution of Internet technology. and maintaining every potential client machine both on the intra- and extra-nets interface. The inherent disadvantage is engines, such as the integrated XML • Scalable, easily configurable addi- the need to install and update client STARLIMS Form Definition (XFD) tional hardware resources and abil- software on every user machine, designer (STARLIMS), can now ity to employ load balancing algo- thereby increasing IT management bur- replace static HTML pages with a rich, rithms to supply uninterruptible den and limiting portability. fully functional GUI equivalent to that service to a growing number of users achieved by thick client versions. • A single application for both design and run time, eliminating the need Early Web-based Leveraging these developments, Web- to maintain special power user ver- applications based version 10 was written for the sions on non-Web-based platforms Microsoft .NET platform using XML • Full enterprise integration via Early Web-based applications offered efﬁ- GUIs and Web services. The .NET Web services cient HTML tools for navigating the platform was chosen because of its • Separation of user interface from Web, and provided broad access to a majority status in the enterprise mar- business logic with standard Web wealth of content. These applications ket, accessibility to scores of program- services used to communicate aim for reach—not rich—which means mers, strong framework for building between the two supporting the widest number of clients at rich GUIs, and built-in support of • Predictable response times the cost of some functionality.3 For exam- ple, the requisite from a LIMS results entry screen is that upon editing a cell, a set of simultaneous processes would be triggered including calculations, valida- tions, and screen. In a pure HTML envi- ronment, complex solutions such as those described above could not be designed and constructed (see Figure 1). Modern Web-based applications Recent developments in programmable eXtensible Markup Language (XML) and SOAP-based Web services are now allowing developers to provide the scal- ability and usability required by com- plex systems such as LIMS. Rich user interfaces created with XML form Figure 2 STARLIMS version 10 architecture. and-drop design tools, the STAR- LIMS XFD designer dynamically cre- ates XML forms containing both lay- out tags, used in a declarative way for describing the user interface, and JScript.NET code, used to program- matically handle these elements, their corresponding events, and make remote calls to business logic services located on the server. Communica- tions between the GUI and the busi- ness logic are achieved via standard Web services. The integrated designer is also used for creating Web services that are made available to third-party client applications for seamless inter- operability between enterprise appli- cations to STARLIMS. Figure 3 STARLIMS version 10 screen. Conclusion Impressive advances in the technol- ogy continuum over the past few years • Easy-to-use design tools that allow ing server, which analyzes the work- have ushered in an era of demand for client system administrators to load and directs requests to the opti- enterprise-wide LIMS data availabil- enhance or modify system func- mal server. ity. This data availability, coupled tionality as required by changing with the emergence of rich, full- business requirements. The STARLIMS client is a standard featured Web-based LIMS, is facilitat- Web browser that hosts a .NET con- ing timely enterprise action, reducing trol charged with dynamically pre- the total cost of ownership, and Architecture senting the user interface. The con- enabling multisite organizations to As demonstrated in Figure 2, version trol, named the STARLIMS XFD conform to best practices. 10 architecture follows that of stan- Renderer, is automatically deployed dard Web-based applications, where on the client every time a new ver- the client side is a Web browser and sion is available. In addition to the References the server side is composed of a scal- classic GUI controls, such as labels, 1. Computer desktop encyclopedia. able and extensible application and buttons, and textboxes, this technol- Retrieved Jul 12, 2005, from database server “farm.” Communica- ogy supports more complex controls www.answers.com/topic/client-server. tions between the client and server such as hierarchical data grids, tab 2. www.microsoft.com/technet/prodtech- are achieved through standard Web controls, and selection boxes. For nol/windowsserver2003/library/TechRef/ service messaging over hypertext data-aware components, special busi- 2cb5c8c9-cadc-44a9-bf39- transfer protocol (HTTP) or option- ness actions called data providers are 856127f4c827.mspx. ally secure HTTP (HTTPS) for a used to interface the GUI with the 3. http://msdn.microsoft.com/library/ more protected environment. data model that resides on the server. default.asp?url=/library/en-us/ For increased security, client-side dnwinforms/html/clickonce.asp. To take advantage of all available pro- scripting code is run in an isolated cessing power and allow for a rich user (sand-boxed) environment, and the experience, version 10 splits its code server side business logic code is sepa- into business logic, which is executed rated from the client-side code. The on the server side, and presentation STARLIMS XFD Renderer uses the code run by a .NET control residing local machine’s computational capa- on the Web client. bilities, resulting in reduced server and network loads (see Figure 3). To provide scalability, STARLIMS application servers utilize hardware The same STARLIMS client when set resources by dynamically creating exe- to design mode exposes the STAR- Mr. Toiba is Vice President, Research & Devel- cution threads that concurrently han- LIMS XFD designer, built to allow opment, STARLIMS Corp., 4000 Hollywood dle business logic requests. The scal- authorized users to intuitively config- Blvd., Ste. 515 S., Hollywood, FL 33021- able distributed server farm is ure business rules and processes as 6755, U.S.A.; tel.: 954-964-8663; fax: 954- continuously monitored by a balanc- requirements change. Through drag- 964-8113; e-mail: firstname.lastname@example.org.
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