In current version of picketlink HAL extension the list of Handler Attributes is not refreshed in the following scenario:

1) Add Federation with Identity Manager to your EAP instance if you dont have one
2) Navigate to http://localhost:9990/console/App.html#picletlink-federation
3) Click view option for previously created federation
4) Change configuration tab to "SAML Handlers"
5) Add two SAML handlers ("aaa" and "bbb")
6) In table below select "aaa" handler
7) in Handler parameter add a new parameter ("paramA", "valueA")
8) Select "bbb" handler in table above

Expected result: the list of parameters for "bbb" handler is empty
Actual result: list of parameters for "aaa" is displayed

at this point it doesn't really matter which handler you select, the list of handler parameters wont refresh.