Basic eScript WebObject

This article is an RSS aggregation from PSDN Code Share.
Originally published on 2006-04-26 by klomastr
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The basic eScript WebObject offers an alternative model for developing WebSpeed applications to those supplied with the Progress and OpenEdge products. Its offers a method of implementing a web user-interface in a way consistent with the model-view-controller (MVC) paradigm recommended by the OpenEdge Reference Architecture.


MVC advocates separating the view that the user sees from the controller and model. The controller is the logic that pertains to a particular class of user-interface and the model is the data and rules that give the application its value. With WebSpeed the view is created using XHTML, cascading style sheets and often a scripting language, such as JavaScript, while the controller is the WebObject. The eScript WebObject allows the view and controller to be separated, allowing one to be changed without the other. For example, it allows the XHTML to be changed without the need to recompile the WebObject. It also means that there can be multiple views for a given WebObject with the one to use being selected by some application defined criteria, such as browser type.


To build a web page, eScript tags are added to the .html file. At runtime, eScripts script processor reads the file and calls the user-defined functions within the WebObject that correspond to the eScript tags. These tags control whether, or how many times, a section of the page will be output and where data will go.


Within the eScriptWO.zip file is a page, eScript Read Me.html, that describes how to install the WebObject into the OpenEdge environment. Also within this file is an example WebObject, custsrch.p, together with its corresponding view, custsearch.html.


The eScript WebObject available here sits at the heart of a framework called ps:eScript that Global Field Services uses when working with customers on WebSpeed assignments. More on this can be found in the ps:eScript FAQ.


If you have questions relating to the use of the eScript WebObject, contact chris.skeldon@progress.com.