net.liftweb.http

RequestVar

abstract class RequestVar[T] extends AnyVar[T, RequestVar[T]] with HasLogUnreadVal

A typesafe container for data with a lifetime nominally equivalent to the lifetime of a page rendered by an HTTP request. RequestVars maintain their value throughout the duration of the current HTTP request and any callbacks for servicing AJAX calls associated with the rendered page. RequestVar instances have no value at the beginning of request servicing (excluding AJAX callbacks) and their value is discarded at the end of request processing. They are commonly used to share values across many snippets. Basic usage:

object MySnippetCompanion { object myRequestVar extends RequestVar[String]("hello") }

The standard pattern is to create a singleton object extending RequestVar instead of creating an instance variable of a concrete RequestVar subclass. This is preferred because RequestVar will use the name of its instantiating class for part of its state maintenance mechanism.

If you find it necessary to create a RequestVar subclass of which there may be more than one instance, it is necessary to override the nameSalt() method to return a unique salt value for each instance to prevent name collisions.

Linear Supertypes
HasLogUnreadVal, AnyVar[T, RequestVar[T]], AnyVarTrait[T, RequestVar[T]], HasCalcDefaultValue[T], PSettableValueHolder[T], SettableValueHolder, Settable, PValueHolder[T], ValueHolder, AnyRef, Any
Known Subclasses
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. RequestVar
  2. HasLogUnreadVal
  3. AnyVar
  4. AnyVarTrait
  5. HasCalcDefaultValue
  6. PSettableValueHolder
  7. SettableValueHolder
  8. Settable
  9. PValueHolder
  10. ValueHolder
  11. AnyRef
  12. Any
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Instance Constructors

  1. new RequestVar(dflt: ⇒ T)

    dflt

    - the default value to be returned if none was set prior to requesting a value to be returned from the container

Type Members

  1. type CleanUpParam = Box[LiftSession]

    Definition Classes
    RequestVar → AnyVarTrait
  2. type ValueType = T

    Definition Classes
    PValueHolder → ValueHolder

Value Members

  1. final def !=(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  2. final def !=(arg0: Any): Boolean

    Definition Classes
    Any
  3. final def ##(): Int

    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  5. final def ==(arg0: Any): Boolean

    Definition Classes
    Any
  6. def __nameSalt: String

    Attributes
    protected
    Definition Classes
    AnyVarTrait
  7. def apply(what: T): T

    Definition Classes
    AnyVarTrait
  8. final def asInstanceOf[T0]: T0

    Definition Classes
    Any
  9. def atomicUpdate(f: (ValueType) ⇒ ValueType): ValueType

    Definition Classes
    Settable
  10. def calcDefaultValue: T

    Attributes
    protected
    Definition Classes
    AnyVar → AnyVarTrait → HasCalcDefaultValue
  11. def clearFunc(name: String): Unit

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait
  12. def clone(): AnyRef

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  13. def doSync[F](f: ⇒ F): F

    Different Vars require different mechanisms for synchronization.

    Different Vars require different mechanisms for synchronization. This method implements the Var specific synchronization mechanism

    Definition Classes
    RequestVar → AnyVarTrait
  14. def doWith[F](newVal: T)(f: ⇒ F): F

    Definition Classes
    AnyVarTrait
  15. final def eq(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  16. def equals(arg0: Any): Boolean

    Definition Classes
    AnyRef → Any
  17. def finalize(): Unit

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  18. def findFunc(name: String): Box[T]

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait
  19. final def generateSnapshotRestorer[T](): (() ⇒ T) ⇒ T

    Generate a function that will take a snapshot of the current RequestVars such that they can be restored

  20. def get: T

    Definition Classes
    AnyVarTrait → ValueHolder
  21. final def getClass(): Class[_]

    Definition Classes
    AnyRef → Any
  22. def hashCode(): Int

    Definition Classes
    AnyRef → Any
  23. def is: T

    Definition Classes
    AnyVarTrait → ValueHolder
  24. final def isInstanceOf[T0]: Boolean

    Definition Classes
    Any
  25. def logUnreadVal: Boolean

    This defines whether or not Lift will log when a RequestVar is set but then not read within the same request cycle.

    This defines whether or not Lift will log when a RequestVar is set but then not read within the same request cycle. Change this to false to turn off logging. Logging can also be turned off globally via LiftRules.logUnreadRequestVars.

    Definition Classes
    RequestVar → HasLogUnreadVal
    See also

    LiftRules#logUnreadRequestVars

  26. lazy val name: String

    Attributes
    protected
    Definition Classes
    AnyVarTrait
  27. final def ne(arg0: AnyRef): Boolean

    Definition Classes
    AnyRef
  28. final def notify(): Unit

    Definition Classes
    AnyRef
  29. final def notifyAll(): Unit

    Definition Classes
    AnyRef
  30. def onShutdown(session: CleanUpParam): Unit

    Attributes
    protected
    Definition Classes
    AnyVarTrait
  31. def performAtomicOperation[T](f: ⇒ T): T

    Definition Classes
    Settable
  32. def registerCleanupFunc(in: (Box[LiftSession]) ⇒ Unit): Unit

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait
  33. final def registerGlobalCleanupFunc(in: (CleanUpParam) ⇒ Unit): Unit

    Attributes
    protected
    Definition Classes
    AnyVarTrait
  34. def remove(): Unit

    Definition Classes
    AnyVarTrait
  35. def set(what: T): T

    Definition Classes
    AnyVarTrait → Settable
  36. def setFunc(name: String, value: T): Unit

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait
  37. def setIsUnset(value: ⇒ T): T

    Definition Classes
    AnyVarTrait
  38. def set_?: Boolean

    Definition Classes
    AnyVarTrait
  39. def settingDefault_?: Boolean

    Attributes
    protected
    Definition Classes
    AnyVarTrait
  40. def snapshot(): () ⇒ Unit

    Return a function that, when applied, will set the value of the RequestVar to its current value

  41. def snapshotGroup: Box[RequestVarSnapshotGroup]

    Is this RequestVar a member of a snapshot group? If so, specify the group here

  42. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  43. def testWasSet(name: String): Boolean

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait
  44. def toString(): String

    Definition Classes
    AnyVarTrait → AnyRef → Any
  45. def update(f: (T) ⇒ T): T

    Definition Classes
    AnyVarTrait
  46. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()
  47. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()
  48. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws()
  49. def wasInitialized(name: String): Boolean

    Attributes
    protected
    Definition Classes
    RequestVar → AnyVarTrait

Inherited from HasLogUnreadVal

Inherited from AnyVar[T, RequestVar[T]]

Inherited from AnyVarTrait[T, RequestVar[T]]

Inherited from HasCalcDefaultValue[T]

Inherited from PSettableValueHolder[T]

Inherited from SettableValueHolder

Inherited from Settable

Inherited from PValueHolder[T]

Inherited from ValueHolder

Inherited from AnyRef

Inherited from Any

Ungrouped