Parameter Configurations

Each of the <plugin>, <action>, <filter>, <dispatch> and <exception-handler> elements may be configured to take a set of parameters by specifying nested <param> elements.

Consequently, the PluginConfig, ActionConfig, FilterConfig, DispatchConfig and ExceptionConfig interfaces extend the ParamsConfig interface, which provides the getParamConfig(String) method to lookup a parameter configuration by its name.

A <param> element itself requires the two attributes

• name, specifying the parameter name, and
• value, specifying the parameter value.

The value attribute is dynamic (that is, its value may contain expressions) and of type string.

A parameter configuration is reflected by the ParamConfig interface, which defines the getName() and getValue() methods.

Example

<action path="/login" class="org.foo.bar.LoginAction">
  <param name="users" value="/WEB-INF/users.xml"/> 
  <dispatch name="success" action="/welcome"/>
  <dispatch name="failure" path="/WEB-INF/jsp/login.jsp"/>
</action>

import de.odysseus.calyxo.control.conf.ParamConfig;
import de.odysseus.calyxo.base.conf.ConfigException;

public class LoginAction extends de.odysseus.calyxo.control.misc.AbstractAction {
  private String users;

  public void init() throws ConfigException {
    ParamConfig param = getActionConfig().getParamConfig("users");
    if (param == null) {
      throw new ConfigException("Missing parameter 'users'!");
    }
    users = param.getValue();
  }
  ...
}