org.apache.click.extras.tree
Class Tree.CookieHandler

java.lang.Object
  org.apache.click.extras.tree.Tree.CookieHandler

All Implemented Interfaces:

Serializable, Tree.JavascriptHandler, TreeListener

Direct Known Subclasses:

CheckboxTree.CheckboxCookieHandler

Enclosing class:

Tree

protected class Tree.CookieHandler
extends Object
implements Tree.JavascriptHandler

Please note this class is only meant for developers of this control, not users.

This class implements a cookie based javascript handler. Cookies in the browser tracks the expand and collapse state of the nodes. When a request is made to the server the cookies is processed and the state of the nodes are modified accordingly.

There are two cookies used to track the state:

• a cookie tracking the expanded node id's
• a cookie tracking the collapsed node id's

The cookies are removed between requests. New requests issue new cookies and update the state of the nodes accordingly.

Note: This class is used in conjunction with cookie-helper.js which manipulates the cookie values in the browser as the user navigates the tree.

See Also:

Serialized Form

Field Summary

protected String	collapsedCookieName Name of cookie responsible for tracking the expanded node id's.
protected String	expandedCookieName Name of cookie responsible for tracking the expanded node id's.
protected Tree.JavascriptRenderer	javascriptRenderer Variable holding a javascript renderer.

Constructor Summary

protected

Tree.CookieHandler(Context context) Creates and initializes a new CookieHandler.

Method Summary

protected Set<String>	asSet(String value, String delim) Returns the specified string value as a set, tokenizing the string based on the specified delimiter.
void	destroy() Called to indicate the user request cycle is complete.
Tree.JavascriptRenderer	getJavascriptRenderer() Returns the javascript renderer associated with this handler.
void	init(Context context) Initialize the handler state from the current cookies.
void	nodeCollapsed(Tree tree, TreeNode node, Context context, boolean oldValue) Removes the specified node from the cookie handler tracker.
void	nodeDeselected(Tree tree, TreeNode node, Context context, boolean oldValue) Invoked when user deselected the specified node.
void	nodeExpanded(Tree tree, TreeNode node, Context context, boolean oldValue) Adds the specified node to the cookie handler tracker.
void	nodeSelected(Tree tree, TreeNode node, Context context, boolean oldValue) Invoked when user selected the specified node.
protected String	prepareCookieValue(String value) Does some preparation on the cookie value like decoding and stripping of unneeded characters.
boolean	renderAsExpanded(TreeNode treeNode) Currently this implementation just calls Tree.isExpandedParent(TreeNode).
protected void	setCookie(String value, String name) Sets a cookie with the specified name and value to the http response.

Methods inherited from class java.lang.Object

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

Field Detail

expandedCookieName

protected final String expandedCookieName

Name of cookie responsible for tracking the expanded node id's.

collapsedCookieName

protected final String collapsedCookieName

Name of cookie responsible for tracking the expanded node id's.

javascriptRenderer

protected Tree.JavascriptRenderer javascriptRenderer

Variable holding a javascript renderer.

Constructor Detail

Tree.CookieHandler

protected Tree.CookieHandler(Context context)

Creates and initializes a new CookieHandler.

Parameters:

context - provides access to the http request, and session

Method Detail

init

public void init(Context context)

Initialize the handler state from the current cookies.

Specified by:

init in interface Tree.JavascriptHandler

Parameters:

context - provides access to the http request, and session

renderAsExpanded

public boolean renderAsExpanded(TreeNode treeNode)

Currently this implementation just calls Tree.isExpandedParent(TreeNode).

CookieHandler uses cookies to sync any state change on the browser with the server, so the handler will not contain any state outside of the treeNode.

Specified by:

renderAsExpanded in interface Tree.JavascriptHandler

Parameters:

treeNode - the specified treeNode to check if it is part of the users selected paths

Returns:

true if the specified treeNode is part of the users selected path, false otherwise

See Also:

renderAsExpanded(TreeNode)

destroy

public void destroy()

Description copied from interface: Tree.JavascriptHandler

Called to indicate the user request cycle is complete. Any last minute tasks can be performed here.

Specified by:

destroy in interface Tree.JavascriptHandler

See Also:

destroy()

getJavascriptRenderer

public Tree.JavascriptRenderer getJavascriptRenderer()

Description copied from interface: Tree.JavascriptHandler

Returns the javascript renderer associated with this handler.

Specified by:

getJavascriptRenderer in interface Tree.JavascriptHandler

Returns:

currently installed javascript renderer

See Also:

getJavascriptRenderer()

nodeExpanded

public void nodeExpanded(Tree tree,
                         TreeNode node,
                         Context context,
                         boolean oldValue)

Adds the specified node to the cookie handler tracker.

Specified by:

nodeExpanded in interface TreeListener

Parameters:

tree - tree the operation was made on

node - node that was expanded

context - provides access to Context

oldValue - contains the previous value of expanded state

See Also:

TreeListener.nodeExpanded(Tree, TreeNode, Context, boolean)

nodeCollapsed

public void nodeCollapsed(Tree tree,
                          TreeNode node,
                          Context context,
                          boolean oldValue)

Removes the specified node from the cookie handler tracker.

Specified by:

nodeCollapsed in interface TreeListener

Parameters:

tree - tree the operation was made on

node - node that was collapsed

context - provides access to Context

oldValue - contains the previous value of selected state

See Also:

TreeListener.nodeCollapsed(Tree, TreeNode, Context, boolean)

nodeSelected

public void nodeSelected(Tree tree,
                         TreeNode node,
                         Context context,
                         boolean oldValue)

Description copied from interface: TreeListener

Invoked when user selected the specified node.

Specified by:

nodeSelected in interface TreeListener

Parameters:

tree - tree the operation was made on

node - node that was selected

context - provides access to Context

oldValue - contains the previous value of selected state

See Also:

TreeListener.nodeSelected(Tree, TreeNode, Context, boolean)

nodeDeselected

public void nodeDeselected(Tree tree,
                           TreeNode node,
                           Context context,
                           boolean oldValue)

Description copied from interface: TreeListener

Invoked when user deselected the specified node.

Specified by:

nodeDeselected in interface TreeListener

Parameters:

tree - tree the operation was made on

node - node that was selected

context - provides access to Context

oldValue - contains the previous value of selected state

See Also:

TreeListener.nodeDeselected(Tree, TreeNode, Context, boolean)

setCookie

protected void setCookie(String value,
                         String name)

Sets a cookie with the specified name and value to the http response.

Parameters:

value - the cookie's value

name - the cookie's name

prepareCookieValue

protected String prepareCookieValue(String value)

Does some preparation on the cookie value like decoding and stripping of unneeded characters.

Parameters:

value - the cookie's value to prepare

Returns:

the prepared value

asSet

protected Set<String> asSet(String value,
                            String delim)

Returns the specified string value as a set, tokenizing the string based on the specified delimiter.

Parameters:

value - value to return as set

delim - delimiter used to tokenize the value

Returns:

set of tokens