RProperty

Public Member Functions
IMPORT_C TInt	Attach ( TUid , TUint , TOwnerType )
IMPORT_C void	Cancel ()
IMPORT_C TInt	Define ( TUid , TUint , TInt , TInt )
IMPORT_C TInt	Define ( TUid , TUint , TInt , const TSecurityPolicy &, const TSecurityPolicy &, TInt )
IMPORT_C TInt	Define ( TUint , TInt , const TSecurityPolicy &, const TSecurityPolicy &, TInt )
IMPORT_C TInt	Delete ( TUid , TUint )
IMPORT_C TInt	Delete ( TUint )
IMPORT_C TInt	Get ( TUid , TUint , TInt &)
IMPORT_C TInt	Get ( TUid , TUint , TDes8 &)
IMPORT_C TInt	Get ( TUid , TUint , TDes16 &)
IMPORT_C TInt	Get ( TInt &)
IMPORT_C TInt	Get ( TDes8 &)
IMPORT_C TInt	Get ( TDes16 &)
IMPORT_C TInt	Set ( TUid , TUint , TInt )
IMPORT_C TInt	Set ( TUid , TUint , const TDesC8 &)
IMPORT_C TInt	Set ( TUid , TUint , const TDesC16 &)
IMPORT_C TInt	Set ( TInt )
IMPORT_C TInt	Set (const TDesC8 &)
IMPORT_C TInt	Set (const TDesC16 &)
IMPORT_C void	Subscribe ( TRequestStatus &)

Inherited Functions
	RHandleBase::Attributes()const
	RHandleBase::BTraceId()const
	RHandleBase::Close()
	RHandleBase::DoExtendedClose()
	RHandleBase::Duplicate(const RThread &,TOwnerType)
	RHandleBase::FullName()const
	RHandleBase::FullName(TDes &)const
	RHandleBase::Handle()const
	RHandleBase::HandleInfo(THandleInfo *)
	RHandleBase::Name()const
	RHandleBase::NotifyDestruction(TRequestStatus &)
	RHandleBase::Open(const TFindHandleBase &,TOwnerType)
	RHandleBase::OpenByName(const TDesC &,TOwnerType,TInt)
	RHandleBase::RHandleBase()
	RHandleBase::RHandleBase(TInt)
	RHandleBase::SetHandle(TInt)
	RHandleBase::SetHandleNC(TInt)
	RHandleBase::SetReturnedHandle(TInt)
	RHandleBase::SetReturnedHandle(TInt,RHandleBase &)

Public Member Enumerations
enum	TType { EInt , EByteArray , EText = EByteArray, ELargeByteArray , ELargeText = ELargeByteArray, ETypeLimit , ETypeMask = 0xff }

Inherited Enumerations
	RHandleBase:TAttributes

Inherited Attributes
	RHandleBase::iHandle

Attach(TUid, TUint, TOwnerType)

IMPORT_C TInt	Attach	(	TUid	aCategory,
			TUint	aKey,
			TOwnerType	aType = EOwnerProcess
		)

Attaches to the specified property.

The function creates a handle (this object) to the specified property. This allows the caller to subscribe for notification of changes to this property, and to faster and real-time property access methods.

If the specified property does not exist, then this operation will still succeed. However, memory allocation will be required. Note that this invalidates any real-time guarantee, i.e. the guarantee that the operation completes within a bounded time.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TOwnerType aType = EOwnerProcess	The ownership of this property handle. By default, ownership is vested in the current process, but can be vested in the current thread by specifying EOwnerThread.

Cancel()

IMPORT_C void

Cancel

(

)

Cancels an outstanding subscription request for this property handle.

If the request has not already completed, then it completes with KErrCancel.

Define(TUid, TUint, TInt, TInt)

IMPORT_C TInt	Define	(	TUid	aCategory,
			TUint	aKey,
			TInt	aAttr,
			TInt	aPreallocate = 0
		)	[static]

NOTE - The use of this method is deprecated.

Defines a property with the specified category ID. This method should only be used to specify a category different from the creating process's secure ID in exceptional circumstances. In most cases the overload:

RProperty::Define(TUint aKey, TInt aAttr, const TSecurityPolicy& aReadPolicy, const TSecurityPolicy& aWritePolicy, TInt aPreallocate)

should be used. For details see the document located at:

Symbian OS guide Base Using User Library (E32) Publish and Subscribe Security issues

Defines the attributes and access control for a property. This can only be done once for each property. Subsequent attempts to define the same property will return KErrAlreadyExists.

Only processes with the write-system-data capability are allowed to define properties either in the system category (KUidSystemCategory) or with aCategory < KUidSecurityThresholdCategoryValue. Any attempt to define a property with these categories by a process with insufficient capabilities will fail with a KErrPermissionDenied error.

Following the property's definition, it will have a default value, 0 for integer properties and zero-length data for byte-array and text properties. Pending subscriptions for this property will not be completed until a new value is published.

capability: WriteDeviceData if aCategory==KUidSystemCategoryValue.

capability: WriteDeviceData if aCategory not equal to the current process's Secure ID and aCategory<KUidSecurityThresholdCategoryValue.

KUidSecurityThresholdCategoryValue Use RProperty::Define (TUint aKey, TInt aAttr, const TSecurityPolicy &aReadPolicy, const TSecurityPolicy &aWritePolicy, TInt aPreallocated=0) instead.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TInt aAttr	This describes the property type, a TType value; persistence, as defined by the KPersistent bit, may be ORed in.
TInt aPreallocate = 0	The number of bytes to be pre-allocated for variable sized properties. Pre-allocating enough space ensures that a variable sized property can be set in 'real-time', (i.e. the time to set the property is bounded).

Define(TUid, TUint, TInt, const TSecurityPolicy &, const TSecurityPolicy &, TInt)

IMPORT_C TInt	Define	(	TUid	aCategory,
			TUint	aKey,
			TInt	aAttr,
			const TSecurityPolicy &	aReadPolicy,
			const TSecurityPolicy &	aWritePolicy,
			TInt	aPreallocated = 0
		)	[static]

Defines a property with the specified category ID. This method should only be used to specify a category different from the creating process's secure ID in exceptional circumstances. In most cases the overload:

RProperty::Define(TUint aKey, TInt aAttr, const TSecurityPolicy& aReadPolicy, const TSecurityPolicy& aWritePolicy, TInt aPreallocate)

should be used. For details see the document located at:

Symbian OS guide Base Using User Library (E32) Publish and Subscribe Security issues

Defines the attributes and access control for a property. This can only be done once for each property. Subsequent attempts to define the same property will return KErrAlreadyExists.

Only processes with the write-system-data capability are allowed to define properties either in the system category (KUidSystemCategory) or with aCategory < KUidSecurityThresholdCategoryValue. Any attempt to define a property with these categories by a process with insufficient capabilities will fail with a KErrPermissionDenied error.

Following the property's definition, it will have a default value, 0 for integer properties and zero-length data for byte-array and text properties. Pending subscriptions for this property will not be completed until a new value is published.

capability: WriteDeviceData if aCategory==KUidSystemCategoryValue.

capability: WriteDeviceData if aCategory not equal to the current process's Secure ID and aCategory<KUidSecurityThresholdCategoryValue.

KUidSecurityThresholdCategoryValue

Parameters

TUid aCategory	The UID that identifies the property category. This must either be the current process's Secure ID, or KUidSystemCategoryValue.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TInt aAttr	This describes the property type, a TType value; persistence, as defined by the KPersistent bit, may be ORed in.
const TSecurityPolicy & aReadPolicy	A security policy defining the security attributes a process must have in order to read this value.
const TSecurityPolicy & aWritePolicy	A security policy defining the security attributes a process must have in order to write this value.
TInt aPreallocated = 0	The number of bytes to be pre-allocated for variable sized properties. Pre-allocating enough space ensures that a variable sized property can be set in 'real-time', (i.e. the time to set the property is bounded).

Define(TUint, TInt, const TSecurityPolicy &, const TSecurityPolicy &, TInt)

IMPORT_C TInt	Define	(	TUint	aKey,
			TInt	aAttr,
			const TSecurityPolicy &	aReadPolicy,
			const TSecurityPolicy &	aWritePolicy,
			TInt	aPreallocated = 0
		)	[static]

Defines a property.

Defines the attributes and access control for a property. This can only be done once for each property. Subsequent attempts to define the same property will return KErrAlreadyExists.

The category ID for the property will be the same as the current processes Secure ID.

Following the property's definition, it will have a default value, 0 for integer properties and zero-length data for byte-array and text properties. Pending subscriptions for this property will not be completed until a new value is published.

Parameters

TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TInt aAttr	This describes the property type, a TType value; persistence, as defined by the KPersistent bit, may be ORed in.
const TSecurityPolicy & aReadPolicy	A security policy defining the security attributes a process must have in order to read this value.
const TSecurityPolicy & aWritePolicy	A security policy defining the security attributes a process must have in order to write this value.
TInt aPreallocated = 0	The number of bytes to be pre-allocated for variable sized properties. Pre-allocating enough space ensures that a variable sized property can be set in 'real-time', (i.e. the time to set the property is bounded).

Delete(TUid, TUint)

IMPORT_C TInt	Delete	(	TUid	aCategory,
			TUint	aKey
		)	[static]

Deletes a property.

This can only be called by the property owner, as defined by the process Security ID; any attempt by another process to delete the property will fail.

Any pending subscriptions for this property will be completed with KErrNotFound. Any new request will not complete until the property is defined and published again.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.

Delete(TUint)

IMPORT_C TInt

Delete

(

TUint

aKey

)

[static]

Deletes a property.

The category ID for the property will be the same as the current processes Secure ID.

Any pending subscriptions for this property will be completed with KErrNotFound. Any new request will not complete until the property is defined and published again.

Parameters

TUint aKey

The property sub-key, i.e. the key that identifies the specific property within the category.

Get(TUid, TUint, TInt &)

IMPORT_C TInt	Get	(	TUid	aCategory,
			TUint	aKey,
			TInt &	aValue
		)	[static]

Gets an integer property.

The function gets the integer value of the specified property.

The Platform Security attributes of the current process are checked against the Read Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TInt & aValue	A reference to the variable where the property value will be reported.

Get(TUid, TUint, TDes8 &)

IMPORT_C TInt	Get	(	TUid	aCategory,
			TUint	aKey,
			TDes8 &	aValue
		)	[static]

Gets a binary property.

The function gets the byte-array (binary) value of the specified property.

The Platform Security attributes of the current process are checked against the Read Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TDes8 & aValue	A reference to the buffer descriptor where the property value will be reported.

Get(TUid, TUint, TDes16 &)

IMPORT_C TInt	Get	(	TUid	aCategory,
			TUint	aKey,
			TDes16 &	aValue
		)	[static]

Gets a text property.

The function gets the text value of the specified property.

The Platform Security attributes of the current process are checked against the Read Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TDes16 & aValue	A reference to the buffer descriptor where the property value will be reported.

Get(TInt &)

IMPORT_C TInt

Get

(

TInt &

aValue

)

Gets the integer value of this property.

The implementation guarantees that this call has a bounded response time.

Parameters

TInt & aValue

A reference to the variable where the property value will be reported.

Get(TDes8 &)

IMPORT_C TInt

Get

(

TDes8 &

aValue

)

Gets the byte-array (binary) value of this property.

The implementation guarantees that this call has a bounded response time.

Parameters

TDes8 & aValue

A reference to the buffer descriptor where the property value will be reported.

Get(TDes16 &)

IMPORT_C TInt

Get

(

TDes16 &

aValue

)

Gets the text value of this property.

The implementation guarantees that this call has a bounded response time.

Parameters

TDes16 & aValue

A reference to the buffer descriptor where the property value will be reported.

Set(TUid, TUint, TInt)

IMPORT_C TInt	Set	(	TUid	aCategory,
			TUint	aKey,
			TInt	aValue
		)	[static]

Sets an integer property.

The function publishes a new integral property value.

Any pending subscriptions for this property will be completed.

The Platform Security attributes of the current process are checked against the Write Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
TInt aValue	The new property value.

Set(TUid, TUint, const TDesC8 &)

IMPORT_C TInt	Set	(	TUid	aCategory,
			TUint	aKey,
			const TDesC8 &	aValue
		)	[static]

Sets a binary property.

The function Publishes a new byte-array (binary) value for the specified property.

Any pending subscriptions for this property will be completed.

Note that if the new property value requires more storage space than is currently allocated, then memory allocation will be required. This invalidates any real-time guarantee, i.e. the guarantee that the operation will complete within a bounded time.

The Platform Security attributes of the current process are checked against the Write Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
const TDesC8 & aValue	A reference to the descriptor containing the new property value.

Set(TUid, TUint, const TDesC16 &)

IMPORT_C TInt	Set	(	TUid	aCategory,
			TUint	aKey,
			const TDesC16 &	aValue
		)	[static]

Sets a text property.

The function publishes a new text value for the specified property.

Any pending subscriptions for this property will be completed.

Note that if the new property value requires more storage space than is currently allocated, then memory allocation will be required. This invalidates any real-time guarantee, i.e. the guarantee that the operation will complete within a bounded time.

The Platform Security attributes of the current process are checked against the Write Policy which was specified when the property was defined. If this check fails the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then this function will return KErrNone even though the check failed.

Parameters

TUid aCategory	The UID that identifies the property category.
TUint aKey	The property sub-key, i.e. the key that identifies the specific property within the category.
const TDesC16 & aValue	A reference to the descriptor containing the new property value.

Set(TInt)

IMPORT_C TInt

Set

(

TInt

aValue

)

Sets a new integer value for this property.

The function publishes the attached new integral property value, and any pending subscriptions for this property are completed.

The implementation guarantees that this call has a bounded response time.

Parameters

TInt aValue

The property new value.

Set(const TDesC8 &)

IMPORT_C TInt

Set

(

const TDesC8 &

aValue

)

Sets the byte-array (binary) property.

The function publishes the attached new binary property value, and any pending subscriptions for this property are completed.

The implementation guarantees that this call has a bounded response time only if the new property value requires no more storage space than is currently allocated. If more memory needs to be allocated, then this invalidates the real-time guarantee.

Parameters

const TDesC8 & aValue

A reference to the descriptor containing the property new value.

Set(const TDesC16 &)

IMPORT_C TInt

Set

(

const TDesC16 &

aValue

)

Sets the text property

The function publishes the attached new text property value, and any pending subscriptions for this property are completed.

The implementation guarantees that this call has a bounded response time only if the new property value requires no more storage space than is currently allocated. If more memory needs to be allocated, then this invalidates the real-time guarantee.

Parameters

const TDesC16 & aValue

A reference to the descriptor containing the property new value.

Subscribe(TRequestStatus &)

IMPORT_C void

Subscribe

(

TRequestStatus &

aRequest

)

Subscribes to a property.

The function issues an asynchronous request to be notified when the property is changed. The calling thread is signalled, and the specified request status object is updated when the property is next changed.

The property may change several times before the subscribing thread can deal with a notification request completion. To ensure that the subscriber does not miss updates, it should re-issue a subscription request before retrieving the current value and acting on it.

If the property has not been defined, the request does not complete until the property is subsequently defined and published. When defined, if the caller process doesn't pass the Read Policy, then the request completes with KErrPermissionDenied.

If the property is already defined, and the caller process doesn't pass the Read Policy, then the request completes immediately with KErrPermissionDenied.

When Read Policy checks fail the action taken is determined by the system wide Platform Security configuration. If PlatSecDiagnostics is ON, then a diagnostic message is emitted. If PlatSecEnforcement is OFF, then the request will complete successfully even though the check failed.

If an outstanding request is cancelled through a call to Cancel() , then it completes with KErrCancel.

panic: KERN-EXEC 9 if there is already a subscription on this property handle; only one subscription per RProperty is allowed.

Parameters

TRequestStatus & aRequest

The request status object to be signalled on update.

Enum TType

Property type attribute.

Enumerators

EInt	Integral property type.
EByteArray	Byte-array (binary data) property type. This type provides real-time guarantees but is limited to a maximum size of 512 bytes. KMaxPropertySize
EText = EByteArray	Text property type. This is just a programmer friendly view of a byte-array property, and is implemented in the same way as EByteArray.
ELargeByteArray	Large byte-array (binary data) property type. This type provides no real-time guarantees but supports properties of up to 65536 bytes. KMaxLargePropertySize
ELargeText = ELargeByteArray	Large text property type. This is just a programmer friendly view of a byte-array property, and is implemented in the same way as EByteArray.
ETypeLimit	Upper limit for TType values. It is the maximal legal TType value plus 1.
ETypeMask = 0xff	Bitmask for TType values coded within TInt attributes.

RProperty Class Reference

Inherits from

Member Functions Documentation

Attach(TUid, TUint, TOwnerType)

Parameters

Cancel()

Define(TUid, TUint, TInt, TInt)

Parameters

Define(TUid, TUint, TInt, const TSecurityPolicy &, const TSecurityPolicy &, TInt)

Parameters

Define(TUint, TInt, const TSecurityPolicy &, const TSecurityPolicy &, TInt)

Parameters

Delete(TUid, TUint)

Parameters

Delete(TUint)

Parameters

Get(TUid, TUint, TInt &)

Parameters

Get(TUid, TUint, TDes8 &)

Parameters

Get(TUid, TUint, TDes16 &)

Parameters

Get(TInt &)

Parameters

Get(TDes8 &)

Parameters

Get(TDes16 &)

Parameters

Set(TUid, TUint, TInt)

Parameters

Set(TUid, TUint, const TDesC8 &)

Parameters

Set(TUid, TUint, const TDesC16 &)

Parameters

Set(TInt)

Parameters

Set(const TDesC8 &)

Parameters

Set(const TDesC16 &)

Parameters

Subscribe(TRequestStatus &)

Parameters

Member Enumerations Documentation

Enum TType

Enumerators