[WIKI-UPDATE] DebuggingWithViews XMLDBTransformer Thu May 15 16:00:03 2003

[st...@outerthought.org]

Page: http://wiki.cocoondev.org/Wiki.jsp?page=DebuggingWithViews , version: 1 on Thu May 15 13:59:11 2003 by 141.211.192.204

New page created:
+ !Overview
+ What do you do when a cocoon page doesn't work? When debugging a cocoon page, you'll often want to view the results at various places in the transformation pipeline in order to identify the step that went wrong. Here's a technique that allows you to do this without having to modify your pipeline logic. This is an especially important point, as it allows you to easily apply this technique to an existing cocoon application without extensive rewriting. 
+ 
+ !Add Debugging Views to Sitemap
+ We make use of a gem in cocoon called [Views]. Views allow you to label parts of a pipeline where you would like to terminate the pipeline and specify an alternate serialzation. It's easier to demonstrate than to explain.
+ 
+ First, in your sitemap.xmap, find the <map:views> element at add the following views for debugging:
+ 
+ {{{
+ 	<map:views>
+ 		<!-- debugging views: add these to your views -->
+ 		<!-- make sure you comment out debugging views before deployment -->
+ 		<map:view from-position="first" name="first">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-position="first" name="firsthtml">
+ 			<map:serialize type="html"/>
+ 		</map:view>
+ 		<map:view from-position="first" name="firsttext">
+ 			<map:serialize type="text"/>
+ 		</map:view>
+ 		<map:view from-label="debug1" name="debug1">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-label="debug2" name="debug2">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-label="debug3" name="debug3">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-label="debug4" name="debug3">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-position="last" name="last">
+ 			<map:serialize type="xml"/>
+ 		</map:view>
+ 		<map:view from-position="last" name="lasthtml">
+ 			<map:serialize type="html"/>
+ 		</map:view>
+ 		<map:view from-position="last" name="lasttext">
+ 			<map:serialize type="text"/>
+ 		</map:view>
+ 	</map:views>
+ }}}
+ 
+ !Prepare Pipeline for Debugging
+ Next, you'll add labels to your pipeline. Let's take the following 5-stage pipeline for example.
+ {{{
+ <map:match pattern="getReport.htm">
+ 	<map:generate src="source.xml"/>
+ 	<map:transform src="prepareSQL.xsl" type="xslt"/>
+ 	<map:transform type="sql"/>
+ 	<map:transform src="displayResult.xsl" type="xslt"/>				
+ 	<map:serialize type="html"/>
+ </map:match>
+ }}}
+ Add labels to the middle three stages of the pipeline as follows ''(Note: labels are not needed for the first and last stages of the pipeline because we've defined the views using from-position="first" and "last", respectively)'' 
+ {{{
+ <map:match pattern="getReport.htm">
+ 	<map:generate src="source.xml"/>
+ 	<map:transform src="prepareSQL.xsl" type="xslt" label="debug1"/>
+ 	<map:transform type="sql" label="debug2"/>
+ 	<map:transform src="displayResult.xsl" type="xslt" label="debug3"/>
+ 	<map:serialize type="html"/>
+ </map:match>
+ }}}
+ Notice that your pipeline logic has not been altered in any way. All you've done is add labels to your pipeline.
+ __You're now ready to go!__
+ 
+ !Using Your Debugging Views
+ Now if your cocoon page www.yourSite.com\getReport.htm gives you an error, you can just append a cocoon-view URL parameter to the page URL to view the results at each stage of the pipeline. To be more concrete, typing:
+ {{{
+ 	www.yourSite.com\getReport.htm&cocoon-view=first
+ 	www.yourSite.com\getReport.htm&cocoon-view=debug1
+ 	www.yourSite.com\getReport.htm&cocoon-view=debug2
+ 	www.yourSite.com\getReport.htm&cocoon-view=debug3
+ 	www.yourSite.com\getReport.htm&cocoon-view=last
+ }}}
+ allows you to view the xml at each of the five stages of the pipeline. __That's it!__
+ 
+ !Comment Out Debugging Views Before Deployment
+ However, you should make sure you don't enable these debugging views on your production application, as it is a __security risk__. Before deploying, you can disable all your debugging views by commenting them out in <map:views>.
+ 
+ I hope this tip helps! Feel free to modify this page.
+ 


Page: http://wiki.cocoondev.org/Wiki.jsp?page=XMLDBTransformer , version: 2 on Thu May 15 13:48:04 2003 by TimGoodwin

- Here's a sitemap snippet that configures a transformer named {{xmldb}} that connects to Xindice running on the local host.
+ Here's a sitemap snippet that configures a transformer named {{xmldb}} that connects to [Xindice|http://xml.apache.org/xindice/] running on the local host.
?                                                                                         +       ++++++++++++++++++++++++++++++++

+ You will also need to copy {{xindice.jar}} from the Xindice distribution to a directory where __Cocoon__ can find it (e.g. {{build/webapp/WEB-INF/lib}}).
+