Hi Viral, I see. Actually you would probably specify a JXPathContext on X and identify the field like this: A/X.
Perhaps you could create your own tag(s) that push or pull the property through a Capco mapping. The tag would have to specifiy the source/destination property (A.X) and mapper (from the mapping configuration). It may be a lot of work and you would have to maintain configuration information two places (the JSP attributes and the mapper), but I think it would allow you to convert A.X as you want. I do my mapping between the FormBean (which holds properly formatted strings) and the business data object used by the logic components (rather than bewteen the tag and the bean). You have probably already ruled that approach out for whatever reason. Good luck. -- Erik. -----Original Message----- From: Viral V. Tolat [mailto:[EMAIL PROTECTED]] Sent: Thursday, September 27, 2001 2:28 PM To: '[EMAIL PROTECTED]' Subject: RE: Data conversion Erik, Thanks for your suggestion. JXPath looks very interesting but I'm not sure it would solve our problem since it's not clear how we could specify a JXPath object for each property on the page. What we want to do is along of the lines of the following: Say there's a Bean A with X getX() and setX ( X ). In the JSP itself we'd like to specify the mechanism to convert X to and from a string. We want to do this in the JSP since there may be many ways to view an instance of X. We would expect to build a bunch of converter classes that do String toString ( X, HTTPServletRequest ) and X fromString ( String, HTTPServletRequest ) for each different conversion. We don't want to add methods to A to do this as A should know nothing about presentation of X or about servlets. We can use the existing pattern A.X to access X from A. That's okay for us and we don't need anything more sophisticated. We don't want to add adaptor methods to A that will convert X for two reasons. One is that we would need another A for every different presentation of X. Second is that there may be many instances of X in an object graph that starts with A. Lastly, the conversion needs information in the ServletRequest since there is context information there that will drive the conversion. The problem is that in the current code, the conversions are done in different places and span BeanUtils, ConvertUtils and RequestUtils, so its hard to find a solution that won't be brittle to potential changes in these files. Thanks, Viral -----Original Message----- From: Erik Worth [mailto:[EMAIL PROTECTED]] Sent: Thursday, September 27, 2001 1:04 PM To: [EMAIL PROTECTED] Subject: RE: Data conversion Hi Viral, I am using the Capco Mapper for data conversion because it basically allows you to map from one abritrary structure to another. I am not using the standard bean getters and setters, but rather setters and getters that use JXPath (http://cvs.apache.org/viewcvs/jakarta-commons/jxpath/). The Capco Mapper is highly extensible and can be extended (via sub-classing rather than editing the original source) to transform virtually anything. I am able to convert from one bean to another, an XML DOM tree to bean hierarchy (and vice versa) and from one DOM tree to another (had to write my own getters and setters for XML DOM traversal, but that was no big deal). You can craft Converters that leverage java.text.MessageFormat to piece together new strings from a resource bundle and some arguments, render a java.util.Data according to a simple data format patter, or extract information out of a string using regular expressions. The architecture is very flexible and well thought out. The only problem I have seen with it is that it references the old struts utilities that have now been moved to commons. -- Erik. -----Original Message----- From: Viral Tolat [mailto:[EMAIL PROTECTED]] Sent: Thursday, September 27, 2001 12:13 PM To: [EMAIL PROTECTED] Subject: Data conversion Is there any intent to modify the code to centralize conversion of strings to objects and reverse? Currently, ConvertUtils is used to convert strings to primitive objects, however, toString is used to convert the object to a string. We'd like to integrate in a data conversion framework but to do this cleanly we need a cental place where all data conversion happens. In addition, we'd need to be able to access the request or page context in order to provide custom conversions on a per page basis. We've looked at the transformations extension and the Capco Mapper, however, we don't see how the transformations can be used with html:text tags to provide data conversion from strings to objects since the Tag is not involved at all in this process. Thanks
