Databind method call returns null in WebCenter Content Filter

Question

Hi,
I have inherited some code that has an issue and I'm new to WebCenter Content and the Filters that can be added. We have a FileNameFilter class that starts off with the code
public class CWEFileNameFilter implements FilterImplementor {
    public CWEFileNameFilter() {
        super();
    public int doFilter(Workspace workspace, DataBinder dataBinder,
                        ExecutionContext executionContext) throws DataException {
        String service = dataBinder.getLocal("IdcService");
However, service sometimes comes back null and then the filter throws a NPE.
My questions are:
1) Can anyone explain what dataBinder.getLocal("IdcService"); is doing and why it could come back as null
2) Can anyone provide any links to documentation that explains Filters and a bit more about the DataBinder object as the JavaDoc isn't much help.
Thanks
Marc

Answer 1

Hi Marc,
Below code will give service name for which filter is implemented  from LocalData
String service = dataBinder.getLocal("IdcService");
for example below
http://localhost:16200/cs/idcplg?IdcService=DOC_INFO_BY_NAME&dDocName=1111111&IsJava
This will print entire response data including localdata and results which are created as part of service execution. Below is snippet
<?hda version="11.1.1.8.0PSU-2015-04-01 00:14:53Z-r126309" jcharset="UTF8" encoding="utf-8"?>
@Properties LocalData
DocUrl=https://localhost:16200/cs/weblayout/groups/secure/documents/test/mhdk/mjg1/1111111.pdf
IdcService=DOC_INFO_BY_NAME
so String service = dataBinder.getLocal("IdcService"); will be service ="DOC_INFO_BY_NAME".
Below blog will give some idea about filter but best place to learn or start is "The Definitive Guide to Stellent Content Server Development" by Brian Huff
http://www.redstonecontentsolutions.com/technical-blog/ucm-service-handlers-and-javafilters
Also i would recommend reading "WebCenter Content Services Reference Guide"
http://docs.oracle.com/cd/E23943_01/doc.1111/e11011/toc.htm
Regards,
Amol Gavali.