InfoWorld review: Tools for rapid Web development

With WYSIWYG prototyping environments and preconfigured graphical components, rapid Web development tools can help you build applications faster -- but with less flexibility

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LANSA for the Web 11.5
LANSA was originally built for IBM System/36 AS/400 systems, but its applications can be compiled to run on Windows or Linux systems, as well as System/38, AS/400, iSeries, and IBM i Systems. Nevertheless, it retains the ability to produce code that uses IBM 5250 terminals as the UI device. LANSA reckons this is a feature and claims that code built to run in its earliest versions can still execute in the current version. Given that the company has been around since the late 1980s, that's impressive. (There are numerous products in LANSA's portfolio. I only examined those used for developing applications.)

LANSA can be used to build applications for the desktop, the Web, and mobile devices. You use LANSA for the Web to create Web applications; it also employs the Visual LANSA development environment and component builder to build WAMs (Web Application Modules).

WAMs are files that correspond roughly to a set of related pages in a Web application. Each is composed of both RDMLX code (LANSA's server-side language) and associated XML/XSL code (that determines client-side appearance and behavior). RDMLX is a descendant of IBM CL (Command Language), the scripting language of the OS/400 operating system. Its scripting roots show: Most commands appear to have the form of an action followed by parameters. It isn't particularly complex, but anyone unused to the language will need time to pick it up.

LANSA keeps the RDMLX and XML/XSL sides separate in the IDE, which helps divide business logic from UI logic. Inside a WAM, code is grouped into Webroutines, each of which defines the behavior of a Web page in an application. It's important to point out that LANSA for the Web can also be used to build Web services -- in which case each Webroutine would correspond to a SOAP function.

When you create an application with LANSA, you're laboring inside the meta-data repository, a database that holds everything the development environment needs to know about all of the objects used to build an application. These objects include source code and back-end database meta-information about tables (referred to as files in LANSA) and attributes (fields). The meta-data repository is roughly analogous to a project file in other IDEs, though it is something more than just a project container. Because it carries information about database fields, it also holds validation information, database triggers, referential integrity information, and even help text.

Visual LANSA for the Web 11.5
Web Application Modules, or WAMs, are composed of both RDMLX, LANSA's server-side language, and associated XML/XSL code.

When you place a particular field on a form, LANSA knows (thanks to the repository) the field's data type, how many characters it includes, what security properties are attached to it, and more. In addition, when you deploy a file/table within an application, LANSA not only deploys the fields of the table (thus defining its structure) and builds any required indexes, but also deploys the database business rules that ensure data integrity.

WebLets are the visual components of LANSA Web design. A WebLet encapsulates display properties and functionality, and it can be dragged and dropped onto a Web page in the development environment. For example, WebLets include primitive components such as check boxes, radio buttons, and text areas, as well as composite components such as a grid or a calendar. LANSA's collection of WebLets are highly parameterized, allowing wide latitude in customization.

From the IDE, you can construct WAMs, their Webroutines, and WebLets. WebLets can be dragged from a palette and dropped onto the Web Designer's WYSIWYG canvas. You can also view the source behind a Web page under construction. The IDE also includes a visual debugger. You can set breakpoints on Webroutines, launch your WAM in the debugger, and single-step through the executing RDMLX code. Other panes in the debugger provide views of current field values.

LANSA requires no special server on the back end. Its runtime system is a plug-in that works on Apache on Linux and iSystem machines, and IIS on Windows systems. It's happy with all the popular RDBMS systems: DB2, Microsoft SQL Server, Oracle, Sybase, and MySQL. Architecturally, LANSA for the Web sits on top of the LANSA runtime, which provides the execution environment for LANSA applications, as well as integrity rules for databases with which LANSA applications interact, and interfaces with a Web server (Apache or IIS).

LANSA's help is extensive. The tool is awash with CHM files, which, in turn, are full of tutorials. There's also context-sensitive help in all the tools and plenty of online tutorials. RDMLX may be off-putting, but there's lots of assistance for neophytes.

Read the next review: OutSystem Agile Platform 5.0

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