KB44575: How to Programmatically Change the Target Selector Value when User Changes the First Selector Using the MicroStrategy Java Web SDK 9.3.1

In Strategy Web, a selector can be configured to target another selector as shown below: 
 

 
Also in Strategy Web, it is possible to change the targeted selector so it will automatically update to a valid value when a combination of selectors is made where no data will return:

 
However, there are times when it is required to programmatically change the targeting selector to a specific value when the user makes a change to the parent selector.  For example the following simple document was created with two selectors and one grid as shown below:
 

 
For example, if a user changes Year to 2011, Quarter will continue to display ‘(All)’. Using the Strategy Java Web SDK, it is possible to specify ‘2011 Q3’ dynamically at the time the user changes Year to 2011. To achieve this customization, follow the steps below:

• In the Web Customization Editor > Application Tab, scroll down and expand Pages
• Expand page rwd(Report Writing Documents) > Beans > rwframe
• Right-click on rwb and select the ‘New Event Handler’ option
• Specify Source Folder, Package, and Name.
• Selector Use Existing Event and Event ID 2048084 as the Event ID
   

• Click Next and Finish. 
•  Once the Java template opens, add the code below.

package customclasses.handlers;
import com.Strategy.utils.StringUtils;
import com.Strategy.web.beans.AggregatedEventHandler;
import com.Strategy.web.beans.GenericRequestKeys;
import com.Strategy.web.beans.RequestKeys;
import com.Strategy.web.beans.WebEvent;
import com.Strategy.web.beans.WebException;


public class RWChangeSelectorEventHandler extends AggregatedEventHandler { 
 
    public RWChangeSelectorEventHandler() {
        super();
    }

    public boolean processRequest(RequestKeys keys) throws WebException {

        WebEvent event = getWebEvent(keys);
        if(event == null) {
            return super.handleDefaultRequest(keys);
        }      

        switch(event.getID()) {
            case 2048084 :            
             //by calling super.handleDefaultRequest ensures that Web will handle the changing the first selector 
             boolean handled = super.handleDefaultRequest(keys);    
             
             boolean newHandled = false;
             
             
             String check = keys.getValue("AlreadyHandled");       
       if(StringUtils.isNotEmpty(check)){
        return handled;         
       }
             
             
             //Create new Requestkeys to change second selector
             
             RequestKeys frameKeys = new GenericRequestKeys();
             
             frameKeys.add("evt", "2048084");  
             frameKeys.add("src", "mstrWeb.rwd.rwframe.rwb.2048084");
             frameKeys.add("ctlKey", "W48");
             frameKeys.add("elemList", "h20113;8D679D4A11D3E4981000E787EC6DE8A4");          
             frameKeys.add("unitKeyContext", "1_F49_W48");
             frameKeys.add("applyNow", "1");
             frameKeys.add("selectorMode", "1");
             frameKeys.add("usePartDisplay", "1");
             frameKeys.add("currentIncludeState", "true");
             frameKeys.add("AlreadyHandled", "1");
             
             //Submit new requestkeys to perform the change of the second selector
             newHandled = getWebComponent().getRoot().handleRequest(frameKeys);             
             
                return newHandled;
            default :
                return super.handleDefaultRequest(keys);
        }

    }

}

 
The example provided in this document is provided “as-is” to the user and assumes that the user:

• Can program, compile (e.g. javac, jikes, etc.), and execute Java programs
• Can configure environment variables (e.g. JAR files, property files, etc.)
• Have all the necessary tools to create Java applications (JDK, IDE, etc.)
• Has access to the Strategy SDK documentation.
• Has read the customization warning at the bottom of this document

 
PREREQUISITES:
For the sample to work, the Strategy Web JAR files must be accessible by the Java Runtime
Environment. The Strategy Web JAR files can be found under:

• Strategy Web Universal (JSP): {web_root}/WEB-INF/lib directory.
• Strategy Web (.NET): Program Files\Common Files\Strategy directory.

Note:
More elaborate programs will require additional library files and are out of the scope of this document.
 
ADDITIONAL INFORMATION:
The Strategy SDK allows you to customize the standard Strategy Web interface, and extend and integrate the Strategy business intelligence functionality into other applications. However, before changing the way Strategy Web products look or behave, it is helpful to understand how the application is built. For more information regarding the Strategy Web architecture or the process of customizing Strategy Web, please refer to Strategy Developer Zone (https://resource.microstrategy.com/msdz/).
 
To access the Strategy Developer Zone, you must have access to the Strategy Knowledge Base, you must have purchased the Strategy SDK, and you must be current on your Strategy maintenance agreement. If you are a US-based business and believe that you satisfy all three of these conditions but you do not have access to the Strategy Developer Zone, please contact Strategy Technical Support at support@microstrategy.com or at (703) 848-8700. If you are an international business, please contact Strategy Technical Support at the appropriate email address or phone number found at http://www.microstrategy.com/Support/ContactUs.asp.
 
 
CUSTOMIZATION WARNING:
This customization is provided as a convenience to Strategy users and is only directly applicable to the version stated. While this code may apply to other releases directly, Strategy Technical Support makes no guarantees that the code provided will apply to any future or previous builds. In the event of a code change in future builds, Strategy Technical Support makes no guarantee that an updated version of this particular customization will be provided. In the event of a code change in future builds, Strategy may not be able to provide additional code on this matter even though this customization is provided at this time for this specific build. For enhancements to this customization or to incorporate similar functionality into other versions, contact your Account Executive to inquire about Strategy Consulting assistance.