PersistDemo.PagePersister

Page persistence handling object. Walks the declared instance or static fields of a System.Web.UI.Page object and saves or restores field values for fields decorated with a PagePersistAttribute. Generally, instance fields are persisted using the Session property bag and static fields are persisted using the Application property bag. Note that static fields of ANY class can be persisted using the Application or web.config files. Only "page" classes can request persistence of instance fields, since that mechanism uses the Session object.

As the code is currently written, persistence can be applied only to protected fields. There are two types of fields: static (class-level or "shared") and object-level. There are three persistence media: the Application dictionary, the Session dictionary and the appSesstings tag in the project's web.config file. This leads to six possible combinations of field and media. In each case, there is a mapping between the field name you chose and the key used in the relevant dictionary. Some media are read-only, others are read-write. Basically, any class can have its static members initialized, but only subclasses of System.Web.UI.Page can have object-level fields persisted at the session level.

Implications of each combination of field type and storage medium are as follows.

Object field, Session storage: Allowed, save and restore. Object must inherit from System.Web.UI.Page. Key is $persist$typeName$fieldName.

Object field, Application storage: Allowed, save and restore. Object must inherit from System.Web.UI.Page. Key is $persist$typeName$fieldName.

Object field, Configuration storage: Allowed, but restore only. Object must inherit from System.Web.UI.Page. Key is $persist$fieldName.

Static field, Session storage: NOT ALLOWED.

Static field, Application storage: Allowed, save and restore. Key is $persist$typeName$fieldName.

Static field, Configuration storage: Allowed, restore only. Key is $persist$typeName$fieldName.

		Members	Description
		PagePersister	Construct a PagePersister for a given page.
		PagePersister	Construct a page persister for static fields of the given type.
		Save	Save instance fields to persistence medium
		Restore	Restore instance fields from persistence medium
		SaveStatic	Save static fields to persistence medium
		RestoreStatic	Restore static fields from persistence medium
		RestoreStatic	Restore persistent static fields for the given class (by type)
		RestorePageStatics	Search for all subclasses of System.Web.UI.Page and restore static fields to each Page class.
		SetPageField	Prepare the application's dictionary so that the value of a page's static field will be set to a particular value when its static fields are restored.
		SetPageField	Prepare the application's dictionary so that the value of a page's static field will be set to a particular value when its static fields are restored.
		SetPageField	Set the persistent value of a persisted page field.
		SetPageField	Set the persistent value of a persisted page field.
		Action	Worker function for persistence: saves or loads static or instance field values.
		PersistPage	Perform page-level persistence for the newly-created or about-to-be-released page
		SessionEnd	Clean up any persisted field values from this session's state collection. That is, call IDisposable.Dispose() on any objects that support it.
		VarName	Generate a string name to use as a key for a persistence data collection. For Session data, the field key is "$persist$classTypeName$fieldName". For Application data, the field key is "$persist$classTypeName$fieldName". For Web Config data, the field key is "$persist$fieldName".
		VarName	Generate a string name to use as a key for a persistence data collection. For Session data, the field key is "$persist$classTypeName$fieldName". For Application data, the field key is "$persist$classTypeName$fieldName". For Web Config data, the field key is "$persist$fieldName".
		sPrefixDelimiter	Delimiter character used between key name components
		sPrefixSession	String prefix to use for session fields (along with type and field name)
		sPrefixApplication	String prefix to use for session fields (along with type and field name)
		sPrefixConfiguration	String prefix to use for web.config fields (along with field name)
		app	The web application for this operation
		page	The page, if any, for this operation
		type	The type of page or object being operated on.
		bindFlagsInstance	The type information binding flags used for walking the instance fields.
		bindFlagsStatic	The type information binding flags used for walking the static fields