public abstract class StateManager
extends java.lang.Object
StateManager directs the process of saving and restoring the view
between requests. An implementation of this class must be
thread-safe. The StateManager
instance for an application is retrieved from the
Application
instance, and thus cannot know any details of the markup language created by
the RenderKit
being used to render a view.
The StateManager
utilizes a helper
object (ResponseStateManager
), that is provided by the RenderKit
implementation
and is therefore aware of the markup language details.
Modifier and Type | Class and Description |
---|---|
class |
StateManager.SerializedView
Deprecated.
This class was not marked
Serializable in the 1.0 version of the
spec. It was also not a static inner class, so it can't be made to be
Serializable . Therefore, it is being deprecated in version 1.2 of
the spec. The replacement is to use an implementation dependent
Object . |
Modifier and Type | Field and Description |
---|---|
static java.lang.String |
FULL_STATE_SAVING_VIEW_IDS_PARAM_NAME
The runtime must interpret the value of this parameter as a comma separated list of view IDs, each of which must have their state saved using the state saving mechanism specified in Jakarta Server Faces 1.2. |
static java.lang.String |
IS_BUILDING_INITIAL_STATE
Marker within the |
static java.lang.String |
IS_SAVING_STATE
Marker within the |
static java.lang.String |
PARTIAL_STATE_SAVING_PARAM_NAME
The |
static java.lang.String |
SERIALIZE_SERVER_STATE_PARAM_NAME
If this param is set, and calling toLowerCase().equals("true") on a String representation of its value returns true, and the javax.faces.STATE_SAVING_METHOD is set to "server" (as indicated below), the server state must be guaranteed to be Serializable such that the aggregate state implements java.io.Serializable. |
static java.lang.String |
STATE_SAVING_METHOD_CLIENT
Constant value for the initialization parameter named by the
STATE_SAVING_METHOD_PARAM_NAME that indicates state saving should take place on
the client. |
static java.lang.String |
STATE_SAVING_METHOD_PARAM_NAME
The
ServletContext init parameter consulted by the StateManager to
tell where the state should be saved. |
static java.lang.String |
STATE_SAVING_METHOD_SERVER
Constant value for the initialization parameter named by the
STATE_SAVING_METHOD_PARAM_NAME that indicates state saving should take place on
the server. |
Constructor and Description |
---|
StateManager() |
Modifier and Type | Method and Description |
---|---|
protected java.lang.Object |
getComponentStateToSave(FacesContext context)
Deprecated.
the distinction between tree structure and component state is now an
implementation detail. The default implementation returns
null . |
protected java.lang.Object |
getTreeStructureToSave(FacesContext context)
Deprecated.
the distinction between tree structure and component state is now an
implementation detail. The default implementation returns
null . |
java.lang.String |
getViewState(FacesContext context)
Convenience method to return the view state as a |
boolean |
isSavingStateInClient(FacesContext context)
Method to determine if the state is saved on the
client.
|
protected void |
restoreComponentState(FacesContext context,
UIViewRoot viewRoot,
java.lang.String renderKitId)
Deprecated.
the distinction between tree structure and component state is now an
implementation detail. The default implementation does nothing.
|
protected UIViewRoot |
restoreTreeStructure(FacesContext context,
java.lang.String viewId,
java.lang.String renderKitId)
Deprecated.
the distinction between tree structure and component state is now an
implementation detail. The default implementation returns
null . |
abstract UIViewRoot |
restoreView(FacesContext context,
java.lang.String viewId,
java.lang.String renderKitId)
Deprecated.
|
StateManager.SerializedView |
saveSerializedView(FacesContext context)
Deprecated.
this has been replaced by
saveView(javax.faces.context.FacesContext) . The default implementation calls
saveView and inspects the return. If the return is an
Object [] , it casts the result to an Object [] wrapping
the first and second elements in an instance of StateManager.SerializedView , which it
then returns. Otherwise, it returns null |
java.lang.Object |
saveView(FacesContext context)
Deprecated.
|
void |
writeState(FacesContext context,
java.lang.Object state)
Save the state represented in the specified state
Object instance, in an
implementation dependent manner. |
void |
writeState(FacesContext context,
StateManager.SerializedView state)
Deprecated.
This method has been replaced by
writeState(javax.faces.context.FacesContext,java.lang.Object) . The
default implementation calls the non-deprecated variant of the method passing an
Object [] as the second argument, where the first element of the
array is the return from getStructure() and the second is the return
from getState() on the argument state . |
public static final java.lang.String STATE_SAVING_METHOD_PARAM_NAME
The ServletContext
init parameter consulted by the StateManager
to
tell where the state should be saved. Valid values are given as the values of the constants:
STATE_SAVING_METHOD_CLIENT
or STATE_SAVING_METHOD_SERVER
.
If this parameter is not specified, the default value is the value of the constant
STATE_SAVING_METHOD_CLIENT
.
public static final java.lang.String PARTIAL_STATE_SAVING_PARAM_NAME
The ServletContext
init parameter consulted by the runtime to determine if the
partial state saving mechanism should be used.
If undefined, the runtime must determine the version level of the application.
For applications versioned at 1.2 and under, the runtime must not use the partial state saving mechanism.
For applications versioned at 2.0 and above, the runtime must use the partial state saving mechanism.
If this parameter is defined, and the application is versioned at 1.2 and under, the runtime
must not use the partial state saving mechanism. Otherwise, If this param is defined, and
calling toLowerCase().equals("true")
on a String
representation of
its value returns true
, the runtime must use partial state mechanism. Otherwise
the partial state saving mechanism must not be used.
public static final java.lang.String FULL_STATE_SAVING_VIEW_IDS_PARAM_NAME
The runtime must interpret the value of this parameter as a comma separated list of view IDs, each of which must have their state saved using the state saving mechanism specified in Jakarta Server Faces 1.2.
public static final java.lang.String IS_SAVING_STATE
Marker within the FacesContext
attributes map to indicate we are saving state.
The implementation must set this marker into the map before starting the state saving
traversal and the marker must be cleared, in a finally block, after the traversal is
complete.
public static final java.lang.String IS_BUILDING_INITIAL_STATE
Marker within the FacesContext
attributes map to indicate we are marking initial
state, so the markInitialState()
method of iterating components such as
UIData
could recognize this fact and save the initial state of
descendents.
public static final java.lang.String SERIALIZE_SERVER_STATE_PARAM_NAME
If this param is set, and calling toLowerCase().equals("true") on a String representation of its value returns true, and the javax.faces.STATE_SAVING_METHOD is set to "server" (as indicated below), the server state must be guaranteed to be Serializable such that the aggregate state implements java.io.Serializable. The intent of this parameter is to ensure that the act of writing out the state to an ObjectOutputStream would not throw a NotSerializableException, but the runtime is not required verify this before saving the state.
public static final java.lang.String STATE_SAVING_METHOD_CLIENT
Constant value for the initialization parameter named by the
STATE_SAVING_METHOD_PARAM_NAME
that indicates state saving should take place on
the client.
public static final java.lang.String STATE_SAVING_METHOD_SERVER
Constant value for the initialization parameter named by the
STATE_SAVING_METHOD_PARAM_NAME
that indicates state saving should take place on
the server.
public StateManager.SerializedView saveSerializedView(FacesContext context)
saveView(javax.faces.context.FacesContext)
. The default implementation calls
saveView
and inspects the return. If the return is an
Object []
, it casts the result to an Object []
wrapping
the first and second elements in an instance of StateManager.SerializedView
, which it
then returns. Otherwise, it returns null
Return the tree structure and component state information for the view contained in the
specified FacesContext
instance as an object of type
StateManager.SerializedView
. If there is no state information to be saved,
return null
instead.
Components may opt out of being included in the serialized view by setting their
transient
property to true
. This must cause the component itself,
as well as all of that component's children and facets, to be omitted from the saved tree
structure and component state information.
This method must also enforce the rule that, for components with non-null id
s,
all components that are descendants of the same nearest NamingContainer
must have
unique identifiers.
context
- FacesContext
for the current requestjava.lang.IllegalStateException
- if more than one component or facet within the same
NamingContainer
in this view has the same non-null
component
id@Deprecated public java.lang.Object saveView(FacesContext context)
The functionality of this method is now handled by
StateManagementStrategy.saveView(javax.faces.context.FacesContext)
. Return an opaque
Object
containing sufficient information for this same instance to restore the
state of the current UIViewRoot
on a subsequent request. The returned object must
implement java.io.Serializable
. If there is no state information to be saved,
return null
instead.
Components may opt out of being included in the serialized view by setting their
transient
property to true
. This must cause the component itself,
as well as all of that component's children and facets, to be omitted from the saved tree
structure and component state information.
This method must also enforce the rule that, for components with non-null id
s,
all components that are descendants of the same nearest NamingContainer
must have
unique identifiers.
For backwards compatability with existing StateManager
implementations, the
default implementation of this method calls saveSerializedView(javax.faces.context.FacesContext)
and creates and
returns a two element Object
array with element zero containing the
structure
property and element one containing the state
property of
the SerializedView
.
context
- FacesContext
for the current requestjava.lang.IllegalStateException
- if more than one component or facet within the same
NamingContainer
in this view has the same non-null
component
idprotected java.lang.Object getTreeStructureToSave(FacesContext context)
null
.
Convenience method, which must be called by saveSerializedView()
, to construct
and return a Serializable
object that represents the structure of the entire
component tree (including children and facets) of this view.
Components may opt-out of being included in the tree structure by setting their
transient
property to true
. This must cause the component itself,
as well as all of that component's children and facets, to be omitted from the saved tree
structure information.
context
- FacesContext
for the current requestprotected java.lang.Object getComponentStateToSave(FacesContext context)
null
.
Convenience method, which must be called by saveSerializedView()
, to construct
and return a Serializable
object that represents the state of all component
properties, attributes, and attached objects, for the entire component tree (including
children and facets) of this view.
Components may opt-out of being included in the component state by setting their
transient
property to true
. This must cause the component itself,
as well as all of that component's children and facets, to be omitted from the saved
component state information.
context
- FacesContext
for the current requestpublic void writeState(FacesContext context, java.lang.Object state) throws java.io.IOException
Save the state represented in the specified state Object
instance, in an
implementation dependent manner.
This method will typically simply delegate the actual writing to the
writeState()
method of the ResponseStateManager
instance provided by the
RenderKit
being used to render this view. This method assumes that the caller has
positioned the ResponseWriter
at the correct position for the saved state to be
written.
For backwards compatability with existing StateManager
implementations, the
default implementation of this method checks if the argument is an instance of
Object []
of length greater than or equal to two. If so, it creates a
SerializedView
instance with the tree structure coming from element zero and the
component state coming from element one and calls through to
writeState(javax.faces.context.FacesContext,javax.faces.application.StateManager.SerializedView)
.
If not, does nothing.
context
- FacesContext
for the current requeststate
- the Serializable state to be written, as returned by saveSerializedView(javax.faces.context.FacesContext)
java.io.IOException
- when an I/O error occurs.public void writeState(FacesContext context, StateManager.SerializedView state) throws java.io.IOException
writeState(javax.faces.context.FacesContext,java.lang.Object)
. The
default implementation calls the non-deprecated variant of the method passing an
Object []
as the second argument, where the first element of the
array is the return from getStructure()
and the second is the return
from getState()
on the argument state
.
Save the state represented in the specified SerializedView
isntance, in an
implementation dependent manner.
This method must consult the context initialization parameter named by the symbolic constant
StateManager.STATE_SAVING_METHOD_PARAM_NAME
to determine whether state should be
saved on the client or the server. If not present, client side state saving is assumed.
If the init parameter indicates that client side state saving should be used, this method
must delegate the actual writing to the writeState()
method of the
ResponseStateManager
instance provided by the RenderKit
being used to render
this view. This method assumes that the caller has positioned the ResponseWriter
at
the correct position for the saved state to be written.
context
- FacesContext
for the current requeststate
- the serialized state to be writtenjava.io.IOException
- when an I/O error occurs.@Deprecated public abstract UIViewRoot restoreView(FacesContext context, java.lang.String viewId, java.lang.String renderKitId)
The functionality of this method is now handled by
StateManagementStrategy.restoreView(javax.faces.context.FacesContext, java.lang.String, java.lang.String)
. Restore the tree
structure and the component state of the view for the specified viewId
, in an
implementation dependent manner, and return the restored UIViewRoot
. If there is no
saved state information available for this viewId
, return null
instead.
This method must consult the context initialization parameter named by the symbolic constant
StateManager.STATE_SAVING_METHOD_PARAM_NAME
to determine whether state should be
saved on the client or the server. If not present, client side state saving is assumed.
If the init parameter indicates that client side state saving should be used, this method
must call the getTreeStructureToRestore()
and (if the previous method call
returned a non-null value) getComponentStateToRestore()
methods of the
ResponseStateManager
instance provided by the RenderKit
responsible for this
view.
context
- FacesContext
for the current requestviewId
- View identifier of the view to be restoredrenderKitId
- the renderKitId used to render this response. Must not be
null
.null
.java.lang.IllegalArgumentException
- if renderKitId
is null
.protected UIViewRoot restoreTreeStructure(FacesContext context, java.lang.String viewId, java.lang.String renderKitId)
null
.
Convenience method, which must be called by restoreView()
, to construct and
return a UIViewRoot
instance (populated with children and facets) representing the
tree structure of the component tree being restored. If no saved state information is
available, return null
instead.
context
- FacesContext
for the current requestviewId
- View identifier of the view to be restoredrenderKitId
- the renderKitId used to render this response. Must not be
null
.null
.java.lang.IllegalArgumentException
- if renderKitId
is null
.protected void restoreComponentState(FacesContext context, UIViewRoot viewRoot, java.lang.String renderKitId)
Convenience method, which must be called by restoreView()
, to restore the
attributes, properties, and attached objects of all components in the restored component
tree.
context
- FacesContext
for the current requestviewRoot
- UIViewRoot
returned by a previous call to
restoreTreeStructure()
renderKitId
- the renderKitId used to render this response. Must not be
null
.java.lang.IllegalArgumentException
- if renderKitId
is null
.public boolean isSavingStateInClient(FacesContext context)
Method to determine if the state is saved on the client.
context
- the Faces context.true
if and only if the value of the ServletContext
init
parameter named by the value of the constant STATE_SAVING_METHOD_PARAM_NAME
is equal (ignoring case) to the value of
the constant STATE_SAVING_METHOD_CLIENT
. false
otherwise.java.lang.NullPointerException
- if context
is null
.public java.lang.String getViewState(FacesContext context)
Convenience method to return the view state as a String
with no
RenderKit
specific markup.
This default implementation of this method will call
saveView(javax.faces.context.FacesContext)
and passing the result to and returning
the resulting value from
ResponseStateManager.getViewState(javax.faces.context.FacesContext, Object)
.
context
- FacesContext
for the current request