com.yworks.yfiles.server.tiles.servlet
Class UpdateServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.yworks.yfiles.server.tiles.servlet.BaseServlet
              com.yworks.yfiles.server.tiles.servlet.UpdateServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

Direct Known Subclasses:

GroupedGraphServlet

public class UpdateServlet

extends BaseServlet

This servlet performs updates on server side graphs. See handlePostRequest(HttpServletRequest, HttpServletResponse) and BaseServlet.handleGetRequest(HttpServletRequest, HttpServletResponse) for details.

There are several protected methods acting on the graph level which are called for handling requests, e.g. createNode(Graph2D, double, double, String). These can be customized in a subclass.

The appaerance of created graph elements can be influenced by setting the defaults, e.g. setDefaultNodeRealizer(NodeRealizer), or by registering custom node realizers (registerNodeRealizer(String, NodeRealizer)).

See Also:

Serialized Form

Constructor Summary

UpdateServlet()

Method Summary

protected void	closeGroup(Graph2D graph, Node node) converts the given group node to a folder node.
protected Edge	createEdge(Graph2D graph, Node source, Node target, int route) is called for creating a new edge.
protected String	createFolderName(Graph2D graph, Node groupNode) is used to provide a an initial name for a newly created folder node.
protected Node	createFolderNode(Graph2D graph, double x, double y, String nodeType, String parentNodeId) creates a new folder node.
protected String	createGroupName(Graph2D graph, Node groupNode) is used to provide a an initial name for a newly created group node.
protected Node	createGroupNode(Graph2D graph, double x, double y, String nodeType, String parentNodeId) creates a new group node.
protected Node	createNode(Graph2D graph, double x, double y, String nodeType) is called for creating a node.
static EdgeRealizer	getDefaultEdgeRealizer() gets the default realizer used to create new edges.
static NodeRealizer	getDefaultFolderNodeRealizer() gets the default realizer used to create new folder nodes.
static NodeRealizer	getDefaultGroupNodeRealizer() gets the default realizer used to create new group nodes.
static NodeRealizer	getDefaultNodeRealizer() gets the default realizer used to create new nodes.
static NodeRealizer	getNodeRealizer(String type) Returns the node realizer registered for the given symbolic name or null.
static String[]	getNodeRealizerTypes() Returns the symbolic names of all registered node realizers.
protected void	handlePostRequest(HttpServletRequest request, HttpServletResponse response) handles update requests.
protected void	moveNodes(Graph2D graph, NodeList nodeList, double deltaX, double deltaY, int route) moves a set of nodes by the given vector.
protected void	moveToSubgraph(Graph2D graph, Node parentNode, NodeList subNodes) moves a set of nodes to the inner graph of the given parent folder or group node.
protected void	openFolder(Graph2D graph, Node node) converts the given folder node to a group node.
static void	registerNodeRealizer(String type, NodeRealizer defaultNodeRealizer) Registers the given node realizers for the given symbolic name.
protected void	removeEdge(Graph2D graph, Edge edge) removes the given edge from the graph.
protected void	removeEdgeLabel(Graph2D graph, EdgeLabel edgeLabel) removes the given edge label from the graph.
protected void	removeNode(Graph2D graph, Node node) removes the given node from the graph.
protected void	removeNodeLabel(Graph2D graph, NodeLabel nodeLabel) removes the given node label from the graph.
static void	setDefaultEdgeRealizer(EdgeRealizer edgeRealizer) sets the default realizer used to create new edges.
static void	setDefaultFolderNodeRealizer(NodeRealizer nodeRealizer) sets the default realizer used to create new folder nodes.
static void	setDefaultGroupNodeRealizer(NodeRealizer nodeRealizer) sets the default realizer used to create new group nodes.
static void	setDefaultNodeRealizer(NodeRealizer nodeRealizer) sets the default realizer used to create new nodes.
protected void	setLabelText(Graph2D graph, Node node, String text) sets the text of the first label of the given node.
protected void	setText(Graph2D graph, NodeLabel nl, String text) sets the text of the given node label.
protected void	switchToSubgraph(HttpSession session, String graphName, Graph2D newGraph, Graph2D oldGraph) switches from an old subgraph to a new subgraph in the same hierarchically organized graph (structure).

Methods inherited from class com.yworks.yfiles.server.tiles.servlet.BaseServlet

addViewConfigurator, cachedGraphs, cacheGraph, doGet, doPost, getEdgeDescription, getEdgeURL, getForId, getGraph, getGraphBounds, getId, getId, getId, getId, getNodeDescription, getNodeURL, getViewConfigurators, getWriter, handleGetRequest, hasDescriptions, hasURLs, init, initialize, newGraph, removeViewConfigurator, setEdgeDescription, setEdgeURL, setNodeDescription, setNodeURL, uncacheGraph, writeWorldBounds

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doHead, doOptions, doPut, doTrace, getLastModified, service, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Constructor Detail

UpdateServlet

public UpdateServlet()

Method Detail

getDefaultNodeRealizer

public static NodeRealizer getDefaultNodeRealizer()

gets the default realizer used to create new nodes.

Returns:

the default node realizer

See Also:

setDefaultNodeRealizer(NodeRealizer)

setDefaultNodeRealizer

public static void setDefaultNodeRealizer(NodeRealizer nodeRealizer)

sets the default realizer used to create new nodes.

Parameters:

nodeRealizer - the default node realizer

See Also:

getDefaultNodeRealizer()

getDefaultEdgeRealizer

public static EdgeRealizer getDefaultEdgeRealizer()

gets the default realizer used to create new edges.

Returns:

the default node realizer

See Also:

setDefaultEdgeRealizer(EdgeRealizer)

setDefaultEdgeRealizer

public static void setDefaultEdgeRealizer(EdgeRealizer edgeRealizer)

sets the default realizer used to create new edges.

Parameters:

edgeRealizer - the default edge realizer

See Also:

getDefaultEdgeRealizer()

getDefaultFolderNodeRealizer

public static NodeRealizer getDefaultFolderNodeRealizer()

gets the default realizer used to create new folder nodes.

Returns:

the default folder node realizer

See Also:

setDefaultFolderNodeRealizer(NodeRealizer)

setDefaultFolderNodeRealizer

public static void setDefaultFolderNodeRealizer(NodeRealizer nodeRealizer)

sets the default realizer used to create new folder nodes.

Parameters:

nodeRealizer - the default folder node realizer

See Also:

getDefaultFolderNodeRealizer()

getDefaultGroupNodeRealizer

public static NodeRealizer getDefaultGroupNodeRealizer()

gets the default realizer used to create new group nodes.

Returns:

the default group node realizer

See Also:

setDefaultGroupNodeRealizer(NodeRealizer)

setDefaultGroupNodeRealizer

public static void setDefaultGroupNodeRealizer(NodeRealizer nodeRealizer)

sets the default realizer used to create new group nodes.

Parameters:

nodeRealizer - the default group node realizer

See Also:

getDefaultGroupNodeRealizer()

handlePostRequest

protected void handlePostRequest(HttpServletRequest request,
                                 HttpServletResponse response)
                          throws ServletException,
                                 IOException

handles update requests. The following requests are handled.

• "newGraph" for creating and caching a new graph
• "createNode", "createEdge", "createGroup" for creating nodes and edges
• "getLabel", "setLabel" for getting and setting the label fo a node or an edge
• "remove", "removeAt" for deleting graph elements
• "moveNodes" for moving a set of nodes
• "closeGroup", "openGroup" for changing the state of group nodes
• "switchToSubgraph", "switchToParent" for changing the displayed nodes in nested graph
• "moveToSubgraph", "moveToParent" for moving nodes across the nested structure of the graph

The parameter "name" is mandatory for all requests. It is the symbolic name of the graph to be used.

This method detects the operation to perform, fetches the necessary parameters from the requests and the graph from the session and then calls one of the pretected methods in this class which act on the graph like createNode(Graph2D, double, double, String).

Overrides:

handlePostRequest in class BaseServlet

Parameters:

request - the request

response - the response to write to

Throws:

ServletException

IOException

moveNodes

protected void moveNodes(Graph2D graph,
                         NodeList nodeList,
                         double deltaX,
                         double deltaY,
                         int route)

moves a set of nodes by the given vector. If a group node is to be moved, all its children are additionally moved (recursively in the case of children which are again group nodes). Moving a non-empty group node with the auto bounds feature normally has no effect, since its bounds are calculated from its children. Note that this implementation temporarily selects some nodes and deselects them later on.

Parameters:

graph - the current graph

nodeList - the nodes to be moved

deltaX - x-coordinate of movement vector (world units)

deltaY - y-coordinate of movement vector (world units)

route - whether to route the affected edges

setText

protected void setText(Graph2D graph,
                       NodeLabel nl,
                       String text)

sets the text of the given node label.

Parameters:

graph - the current graph

nl - the node label

text - the new text for the label

setLabelText

protected void setLabelText(Graph2D graph,
                            Node node,
                            String text)

sets the text of the first label of the given node.

Parameters:

graph - the current graph

node - the node

text - the new text for the first node label

createNode

protected Node createNode(Graph2D graph,
                          double x,
                          double y,
                          String nodeType)

is called for creating a node. If nodeType is null the default node realizer is used. Subclasses can overwrite this method.

Parameters:

graph - the graph to add a node to

x - the x coordinate of the new node in world coordinates

y - the y coordinate of the new node in world coordinates

nodeType - the type of node to be created (may be null)

Returns:

the new node

See Also:

getDefaultNodeRealizer(), registerNodeRealizer(String, NodeRealizer), getNodeRealizerTypes()

createGroupNode

protected Node createGroupNode(Graph2D graph,
                               double x,
                               double y,
                               String nodeType,
                               String parentNodeId)

creates a new group node. The new node is created in the given graph (if no parent node id is given) or as a child of the group or folder node with the given parent node id. This method is called for handling "createGroup" requests.

Parameters:

graph - the current subgraph

x - x-coordinate of the center of the new group node

y - y-coordinate of the center of the new group node

nodeType - a symbolic name for a type of node to create, if null the default is used

parentNodeId - id of the parent node of the new group node (may be null)

Returns:

a new group node

See Also:

getDefaultGroupNodeRealizer()

createFolderNode

protected Node createFolderNode(Graph2D graph,
                                double x,
                                double y,
                                String nodeType,
                                String parentNodeId)

creates a new folder node. The new node is created in the given graph (if no parent node id is given) or as a child of the group or folder node with the given parent node id. This method is called for handling "createGroup" requests.

Parameters:

graph - the current subgraph

x - x-coordinate of the center of the new folder node

y - y-coordinate of the center of the new folder node

nodeType - a symbolic name for a type of node to create, if null the default is used

parentNodeId - the id of the parent node for the new folder node (may be null)

Returns:

a new folder node

See Also:

getDefaultFolderNodeRealizer()

createGroupName

protected String createGroupName(Graph2D graph,
                                 Node groupNode)

is used to provide a an initial name for a newly created group node.

Parameters:

graph - the current subgraph

groupNode - the node to be named

Returns:

the name

createFolderName

protected String createFolderName(Graph2D graph,
                                  Node groupNode)

is used to provide a an initial name for a newly created folder node.

Parameters:

graph - the current subgraph

groupNode - the node to be named

Returns:

the name

openFolder

protected void openFolder(Graph2D graph,
                          Node node)

converts the given folder node to a group node. This method is called to serve the "openFolder" request. If the given node is not a folder node, the method just does nothing.

Parameters:

graph - the current subgraph.

node - the folder to be opened

closeGroup

protected void closeGroup(Graph2D graph,
                          Node node)

converts the given group node to a folder node. This method is called to serve the "closeGroup" request. If the given node is not a group node, the method just does nothing.

Parameters:

graph - the current subgraph.

node - the group to be closed

switchToSubgraph

protected void switchToSubgraph(HttpSession session,
                                String graphName,
                                Graph2D newGraph,
                                Graph2D oldGraph)

switches from an old subgraph to a new subgraph in the same hierarchically organized graph (structure). This method is called to serve the "switchToSubgraph" as well as the "switchToParent" requests and can be extended in subclasses. In this case it is important to include a super call.

Parameters:

session - the session for the request

graphName - the symbolic name of the whole hierarchically organized graph

newGraph - the subgraph to switch to

oldGraph - the subgraph before serving the request

moveToSubgraph

protected void moveToSubgraph(Graph2D graph,
                              Node parentNode,
                              NodeList subNodes)

moves a set of nodes to the inner graph of the given parent folder or group node. The method simply returns, if the given parentNode is already the parent of the nodes to be moved or if a node should be moved to a subgraph of itself.

Parameters:

graph - the current graph

parentNode - the new parent for the nodes to be moved, null for the root graph

subNodes - the nodes to be moved

createEdge

protected Edge createEdge(Graph2D graph,
                          Node source,
                          Node target,
                          int route)

is called for creating a new edge. Subclasses can overwrite this method.

Parameters:

graph - the graph to add an edge to

source - the source node for the edge

target - the target node for the edge

route - if this is not equal to zero, the new edge should be routed

Returns:

the new edge

removeNode

protected void removeNode(Graph2D graph,
                          Node node)

removes the given node from the graph. This method is called for handling "remove" and "removeAt" requests.

Parameters:

graph - the current graph

node - the node to be removed

removeEdge

protected void removeEdge(Graph2D graph,
                          Edge edge)

removes the given edge from the graph. This method is called for handling "remove" and "removeAt" requests.

Parameters:

graph - the current graph

edge - the edge to be removed

removeNodeLabel

protected void removeNodeLabel(Graph2D graph,
                               NodeLabel nodeLabel)

removes the given node label from the graph. This method is called for handling "remove" requests.

Parameters:

graph - the current graph

nodeLabel - the node label to be removed

removeEdgeLabel

protected void removeEdgeLabel(Graph2D graph,
                               EdgeLabel edgeLabel)

removes the given edge label from the graph. This method is called for handling "remove" requests.

Parameters:

graph - the current graph

edgeLabel - the node label to be removed

registerNodeRealizer

public static void registerNodeRealizer(String type,
                                        NodeRealizer defaultNodeRealizer)

Registers the given node realizers for the given symbolic name. The registered realizers can be used in client requests for creating nodes which are handled by createNode(Graph2D, double, double, String). No node realizers are registered initially.

Parameters:

type - a symbolic name

defaultNodeRealizer - a node realizer

See Also:

createNode(Graph2D, double, double, String), getNodeRealizer(String), getNodeRealizerTypes()

getNodeRealizer

public static NodeRealizer getNodeRealizer(String type)

Returns the node realizer registered for the given symbolic name or null.

Parameters:

type - a symbolic name

Returns:

the node realizer registered for the given symbolic name or null

See Also:

registerNodeRealizer(String, NodeRealizer)

getNodeRealizerTypes

public static String[] getNodeRealizerTypes()

Returns the symbolic names of all registered node realizers. No node realizers are registered initially.

Returns:

an array of symbolic names

See Also:

registerNodeRealizer(String, NodeRealizer)