atg.repository.servlet
Class NavHistory

java.lang.Object
  atg.nucleus.logging.VariableArgumentApplicationLoggingImpl
      atg.nucleus.logging.ApplicationLoggingImpl
          atg.repository.servlet.NavHistory

All Implemented Interfaces:

ApplicationLogging, atg.nucleus.logging.ApplicationLoggingSender, atg.nucleus.logging.TraceApplicationLogging, VariableArgumentApplicationLogging

Direct Known Subclasses:

CatalogNavHistory

public class NavHistory
extends ApplicationLoggingImpl

When you are walking in the woods, experts recommend carrying a loaf of bread and throwing down bread crumbs everywhere you walk so that when you would like to return, you can follow a trail of breadcrumbs to your home.

In this implementation of bread crumbs we will keep track of the path that the user has traversed from the top of the site to the current location. We will keep a stack of locations visited and move items on and off that stack as needed to keep the list a concise path from user's current position to the "top" of the site.

This class is intended to be instantiated as a session scoped component and used with the NavHistoryCollector.

There are 4 ways that a user can move:

1. When the user navigates in the forward direction or down the hierarchy, we push another item on the stack.
2. When he navigates up the hierarchy by clicking on breadcrumb or another navigational item, we will pop the appropriate number of items off the stack.
3. If the user hits the back button one or more times and then resumes navigation we are able to recognize that and reset the navigation path, so that we will add breadcrumbs from the position at which navigation was resumed rather than the farthest point the user reached.
4. Finally, if the user jumps to an unrelated area of the site, as if by a global navigation or some other link, we can jump to that area. If there is a default navigation path to the page jumped to, as in a hierarchical structure, that will be filled in. However, to have anything filled in you must extend this class and implement the getDefaultHistory() method as appropriate to your repository structure.

   This works for navigation among items in a single repository or multiple repositories. If you have a site with a catalog and a magazine, for example, and each has a separate repository, then you can use a single NavHistory for the whole site or you may maintain a MagazineNavHistory and a CatalogNavHistory service so that you can remember position in the Magazine while the user visits the catalog and vice versa.

   Usage:

   The property NavHistory.navHistory is a LinkedList of objects which may be RepositoryItem or NavHistoryItems which represent the special pages like "search" and "home". To render the navigation history, which gives upwards navigation:

    <droplet bean="/atg/dynamo/droplet/ForEach">
      <param name="array" value="property:NavHistory.navHistory">
      <oparam name="output">
         <a href="param:element.template.url">
         <param name="itemType" value="param:element.itemDescriptor.itemDescriptorName">
         <param name="itemId" value="param:element.repositoryId">
         <param name="navAction" value="pop">
         <valueof param="element.displayName"></valueof>
         </a>
      </oparam>
    </droplet>
   

   Field Summary

   static java.lang.String

   CLASS_VERSION Class version string

   Fields inherited from interface atg.nucleus.logging.TraceApplicationLogging

   DEFAULT_LOG_TRACE_STATUS

   Fields inherited from interface atg.nucleus.logging.ApplicationLogging

   DEFAULT_LOG_DEBUG_STATUS, DEFAULT_LOG_ERROR_STATUS, DEFAULT_LOG_INFO_STATUS, DEFAULT_LOG_WARNING_STATUS

   Constructor Summary

   NavHistory()
   

   Method Summary

   java.util.LinkedList	getDefaultHistory(java.lang.Object pItem) Use this method to return the navhistory to display if there is no actual history in the user's session.
   int	getNavCount()
   java.util.LinkedList	getNavHistory()
   void	incrementNavCount()
   boolean	navigate(java.lang.Object pItem, java.lang.String pNavAction) This method uses navAction to decide how to place pItem on the NavHistory property and then does it.
   void	resetHistory() this method erases all navHistory
   void	setNavCount(int pNavCount)
   void	setNavHistory(java.util.LinkedList pNavHistory)
   java.lang.String	toString() For debugging purposes, this method can be used to print the contents of the navHistory property.

   Methods inherited from class atg.nucleus.logging.ApplicationLoggingImpl

   addGlobalLogListeners, addLogListener, getLoggingForVlogging, getLoggingIdentifer, getLoggingIdentifier, getLogListenerCount, getLogListeners, initializeFromServiceEvent, isAutoInitListeners, isLoggingDebug, isLoggingError, isLoggingInfo, isLoggingTrace, isLoggingWarning, logDebug, logDebug, logDebug, logError, logError, logError, logInfo, logInfo, logInfo, logTrace, logTrace, logTrace, logWarning, logWarning, logWarning, removeLogListener, sendLogEvent, setAutoInitListeners, setLoggingDebug, setLoggingError, setLoggingIdentifier, setLoggingInfo, setLoggingTrace, setLoggingWarning

   Methods inherited from class atg.nucleus.logging.VariableArgumentApplicationLoggingImpl

   vlogDebug, vlogDebug, vlogDebug, vlogDebug, vlogError, vlogError, vlogError, vlogError, vlogInfo, vlogInfo, vlogInfo, vlogInfo, vlogTrace, vlogTrace, vlogTrace, vlogTrace, vlogWarning, vlogWarning, vlogWarning, vlogWarning

   Methods inherited from class java.lang.Object

   clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

   Field Detail

   CLASS_VERSION

   public static java.lang.String CLASS_VERSION

   Class version string

   Constructor Detail

   NavHistory

   public NavHistory()

   Method Detail

   setNavHistory

   public void setNavHistory(java.util.LinkedList pNavHistory)

   getNavHistory

   public java.util.LinkedList getNavHistory()

   setNavCount

   public void setNavCount(int pNavCount)

   getNavCount

   public int getNavCount()

   incrementNavCount

   public void incrementNavCount()

   resetHistory

   public void resetHistory()

   this method erases all navHistory

   navigate

   public boolean navigate(java.lang.Object pItem,
                           java.lang.String pNavAction)

   This method uses navAction to decide how to place pItem on the NavHistory property and then does it.

   getDefaultHistory

   public java.util.LinkedList getDefaultHistory(java.lang.Object pItem)

   Use this method to return the navhistory to display if there is no actual history in the user's session. For example, if there is a hierarchical structure to your repository, if a user jumps to some item, you can display that item's parent category, and the 'grandparent' up to the top of the hierarchy. In this base class, we return an empty linked list, but the developer is encouraged to override this method to fit the structure of the repository being navigated.

   toString

   public java.lang.String toString()

   For debugging purposes, this method can be used to print the contents of the navHistory property.

   Overrides:

   toString in class java.lang.Object