Some portlet developers have hard time to set up a correct environment to use invalidation based cache with portlets. The summary is often:
"it is working with the PDK Example provided in Oracle 9iAS but every time that I want to do it myself from Oracle JDeveloper or a stand alone OC4J the portlet is not cached !"

I had some questions about the limitation to 5 columns of the OmniPortlet tabular layout. Here is a tip to add more columns to this layout:

1. backup the current OmniPortlet provider.xml /OC4J_HOME/applications/portalTools/omniPortlet/WEB-INF/providers/omniPortlet

2. You can now open the file, and look for the tag <dataField

3. You can add new fields, by copying the existing <dataField> tag and change the value of the <name> and <displayName>

<dataField class="oracle.webdb.reformlet.definition.DataFieldDefinition">
<name>Field6</name>
<displayName>Column6</displayName>
<description>Field6</description>
<text>##column##</text>

<alignment>left</alignment>
<displayAs>hidden</displayAs>
<type>linebreak</type>
<font>Arial.3.Plain.None</font>

<color>#000000</color>
<style>none</style>
<styleType>custom</styleType>
</dataField>

The same logic could be used to add parameters or events to the OmniPortlet.

You are implementing a Portal based on Oracle 9iAS Portal, do not reinvent the wheel !

The Portal Center Knowledge Exchange is a great place to find portlets, articles, tips and technics from the Portlet Developer Community ! You just have to suscribe for free to the Developer Services

To have a better control of the layout of your Portal Pages, you can use a vertical scroll bar in portlet wihout having to use iFrame technology. CSS provide us lof of power to do it.

1. Create a style in your portlet (or in the portlet container code):

<style>
.scroll<i>portletId</i> {
  height:200px;
  overflow: auto;
}
</style>

2. Use this style in a DIV section:

<div class="scrollportletId">
The content of this section will be vertically scrollable.
</div>