To follow up with an old post about handling continuation ids as request
parameters and how that could cause caching problems:
I wrote a quick set of changes to add the continuation id as a cookie in
the setup method of one of my generators as follows:
WebContinuation m_kont = FlowHelper.getWebContinuation(
objectModel );
if ( m_kont != null )
{
String id = m_kont.getContinuation(0).getId();
if ( id != null )
{
Response response = (Response)objectModel.get(
ObjectModelHelper.RESPONSE_OBJECT );
Cookie cookie = response.createCookie(
CONTINUATION_ID, id );
cookie.setMaxAge( -1 ); // Save in
memory only
cookie.setPath( "/" );
cookie.setVersion( 0 );
response.addCookie( cookie );
response.addHeader( "expires", "0" );
objectModel.put(
ObjectModelHelper.RESPONSE_OBJECT, response );
}
}
I then wrote a CookieValueModule as an input module to get the value of
a cookie:
public class CookieValueModule extends AbstractInputModule implements
ThreadSafe {
public Object getAttribute( String name, Configuration modeConf, Map
objectModel ) throws ConfigurationException {
String pname = (String) this.settings.get("parameter", name);
if ( modeConf != null ) {
pname = modeConf.getAttribute( "parameter", pname );
// preferred
pname = modeConf.getChild("parameter").getValue(pname);
}
Map cookies =
ObjectModelHelper.getRequest(objectModel).getCookieMap();
Cookie cookie = (Cookie)cookies.get( pname );
if ( cookie != null )
{
return cookie.getValue( );
}
return null;
}
public Iterator getAttributeNames( Configuration modeConf, Map
objectModel ) throws ConfigurationException {
Map cookies =
ObjectModelHelper.getRequest(objectModel).getCookieMap();
if ( cookies != null )
return cookies.keySet().iterator();
return null;
}
public Object[] getAttributeValues( String name, Configuration
modeConf, Map objectModel )
throws ConfigurationException {
Map cookies =
ObjectModelHelper.getRequest(objectModel).getCookieMap();
String pname = (String) this.settings.get("parameter", name);
Cookie cookie = (Cookie)cookies.get( pname );
if ( cookie != null )
{
Vector ret = new Vector();
ret.add( cookie.getValue( ) );
return ret.toArray();
}
return null;
}
}
I added this module to my Cocoon.xconf (with the name "cookie-value")
and then in the sitemap I can do:
<map:match pattern="*/**">
<map:select type="request-method">
<map:when test="POST">
<map:call
continuation="{cookie-value:continuation-id}"/>
</map:when>
<map:otherwise>
<map:call function="main">
<map:parameter name="p1" value="{1}"/> <!--
this will get mapped to the 1st param of the main function -->
<map:parameter name="p2" value="{2}"/> <!--
this will get mapped to the 2nd param of the main function -->
</map:call>
</map:otherwise>
</map:select>
</map:match>
This removes the need to manage continuation ids completely from any of
the XSLTs.
I think that it might make sense for Cocoon to do this automatically in
the setup method of the AbstractGenerator? (I think a cookie can only
be added once? If not, we'd need a way to only add it once...)
Certainly a generic CookieValue Module might help. In any case, if
anyone needs this and can't figure it out from the above let me know.
Peter Hunsberger
