CBNFParser Class Reference

iCurrentRule

[protected]

The BNF rule that is currently being processed.

iLUT

CFragmentedString::TStringMatch

iLUT

[protected]

Storage object for all the attributes and identifiers in a tree

iMatched

iMatched

[protected]

Input stream matched rule flag.

iMoreCount

const TDesC *

iMoreCount

[protected]

Stores attribute identifier for nmore count attributes.

iMoreMaximum

const TDesC *

iMoreMaximum

[protected]

Stores attribute identifier for nmore maximum attributes.

iMoreMinimum

const TDesC *

iMoreMinimum

[protected]

Stores attribute identifier for nmore minimum attributes.

iOptionalMatched

iOptionalMatched

[protected]

Flag that indicates when returning to a rule in the rulestack if an optional rule matched correctly.

iParsing

TParseState

iParsing

[protected]

Parser state.

iPostRuleCallback

const TDesC *

iPostRuleCallback

[protected]

Stores attribute identifier for post-rule callback attributes.

iPreRuleCallback

const TDesC *

iPreRuleCallback

[protected]

Stores attribute identifier for pre-rule callback attributes.

iRangeEnd

const TDesC *

iRangeEnd

[protected]

Stores attribute identifier for range end attributes.

iRangeStart

const TDesC *

iRangeStart

[protected]

Stores attribute identifier for range start attributes.

iReferenceString

const TDesC *

iReferenceString

[protected]

Stores attribute identifier for reference string attributes.

iRuleStack

CRuleStack

iRuleStack

[protected]

A stack of rules from iTree which are waiting to be completed. The stack basically holds the path along the rule tree.

iString

CFragmentedString

iString

[protected]

An utility object which stores all the buffers passed into the parser and represents them as if they would form a single, continuous string. This class also performs the actual physical matching/selection of the strings and holds the marks set onto the string.

iStringComplete

iStringComplete

[protected]

Flag indicating if the input stream has been completely processed.

iSubRule

iSubRule

[protected]

The child rule we are returning from (if any). If this is NULL we are new to this BNF rule.

iSubRuleMatched

iSubRuleMatched

[protected]

Flag that indicates when returning to a rule in the rulestack if the child rule matched correctly.

iTree

iTree

[protected]

The BNF tree the parser is using to parse the input stream.

Constructor & Destructor Documentation

CBNFParser ( CAttributeLookupTable & )

IMPORT_C

CBNFParser

(

aLUT

)

[protected]

Constructor.

Parameters
aLUT	Attribute lookup table

~CBNFParser ( )

IMPORT_C

~CBNFParser

(

)

[virtual]

Destructor.

Member Function Documentation

AddComponentAttributeL ( CBNFNode &, CBNFNodeAttributeType, TInt )

IMPORT_C void	AddComponentAttributeL	(	CBNFNode &	aRule,
			CBNFNodeAttributeType	aAttribute,
			TInt	aInt
		)

Adds an additional attribute to an existing rule node.

For example, this is used with range rules, which specify the range boundaries using start and end attributes.

Parameters
aRule	Rule node on which to set the attribute
aAttribute	Attribute type
aInt	Attribute value

AddRuleCallbackL ( CBNFNode &, const TDesC , TRuleCallback )

IMPORT_C void	AddRuleCallbackL	(	CBNFNode &	aRule,
			const TDesC *	aCallbackID,
			TRuleCallback *	aCallback
		)	[protected, virtual]

Adds a callback to a rule.

Parameters
aRule	The rule to which the callback is to be added
aCallbackID	Callback type: either CBNFNode::KPreRuleCallback() or CBNFNode::KPostRuleCallback()
aCallback	Callback function

AndL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	AndL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an EAnd rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

AttributeLUT ( )

IMPORT_C CAttributeLookupTable &

AttributeLUT

(

)

const [protected]

Gets the attribute look-up table used by this parser.

Return Value: Attribute look-up table

CommitL ( )

IMPORT_C void

CommitL

(

)

Notifies the parser that all the data has been passed in.

It causes the parser to parse any of the input stream not already parsed.

CurrentRule ( )

CurrentRule

(

)

[inline]

Gets a pointer to the rule node currently being processed.

Return Value: Rule node

DeleteMark ( )

void

DeleteMark

(

)

[inline]

Removes the latest mark. All the marks are stored in a stack and this removes the topmost mark.

EndConditional ( TParserNodeTypes, TBool )

IMPORT_C void	EndConditional	(	TParserNodeTypes	aRuleType,
			TBool	aSuccess
		)	[protected, virtual]

ExactL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	ExactL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an EExact rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

ExecutePostRuleCallbackL ( CBNFNode & )

IMPORT_C void

ExecutePostRuleCallbackL

(

CBNFNode &

aRule

)

[protected, virtual]

Executes a post-rule callback function.

Parameters
aRule	Node specifying the callback

ExecutePreRuleCallbackL ( CBNFNode & )

IMPORT_C void

ExecutePreRuleCallbackL

(

CBNFNode &

aRule

)

[protected, virtual]

Executes a pre-rule callback function.

Parameters
aRule	Node specifying the callback

MDataProviderObserverReserved1 ( )

IMPORT_C void

MDataProviderObserverReserved1

(

)

[virtual]

Reimplemented from MDataProviderObserver::MDataProviderObserverReserved1()

Intended Usage : Reserved for future expansion.

Since: 6.0

MDataProviderObserverReserved2 ( )

IMPORT_C void

MDataProviderObserverReserved2

(

)

[virtual]

Reimplemented from MDataProviderObserver::MDataProviderObserverReserved2()

Intended Usage : Reserved for future expansion.

Since: 6.0

Mark ( )

void

Mark

(

)

[inline]

Set a mark to the current position of the input stream.

The mark acts as a tag in the stream currently being processed. As we process further along the stream after adding the mark, we can perform a rollback to the most previously set mark and start processing again (e.g. OR rule works this way). The string fragments won't be consumed (deleted) until all the marks on a fragment (and fragments before that) are deleted.

MarkCallback ( CBNFParser & )

IMPORT_C void

MarkCallback

(

CBNFParser &

aParser

)

[protected, static]

Inserts a mark to the current position of the stream being processed.

Adding a mark is a very common callback operation before starting to process a rule, so the method is provided by the parser.

Parameters
aParser	Parser processing the stream

MarkedL ( )

HBufC *

MarkedL

(

)

[inline]

Get string between the "cursor position" and the latest mark on the stream.

Return Value: Pointer to the string from the previous mark on to the current position of processed string. OWNERSHIP OF THE STRING GIVEN TO THE CALLER.

MarkedWithInitialTextL ( const TDesC & )

HBufC *

MarkedWithInitialTextL

(

const TDesC &

aInitialText

)

[inline]

Gets the marked string with a string added before the mached string.

NMoreL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	NMoreL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an ENMore rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

NewBNFL ( )

IMPORT_C CBNFNode *

NewBNFL

(

)

Creates a new rule tree root node.

It creates a new single instance of CBNFNode as the root node of the rule tree. All the top-level rules are attached as attributes to this node. The root node should have single child node, which should be a reference to the logical root of the rule tree. This can be done be attaching the logical root rule as a component to the root rule.

Return Value: New rule tree root node

NewComponentL ( TParserNodeTypes, const TDesC & )

IMPORT_C CBNFNode *	NewComponentL	(	TParserNodeTypes	aRuleType,
			const TDesC &	aData
		)

Creates a new rule node, but does not add it to the tree.

This overload sets no rule callbacks.

Parameters
aRuleType	Rule type
aData	Rule data reference. This is used with EExact and ESelect type rules to match actual text strings.

Return Value: The new rule node

NewComponentL ( TParserNodeTypes, HBufC , TRuleCallback , TRuleCallback * )

IMPORT_C CBNFNode *	NewComponentL	(	TParserNodeTypes	aRuleType,
			HBufC *	aData = NULL,
			TRuleCallback *	aPreRule = NULL,
			TRuleCallback *	aPostRule = NULL
		)

Creates a new rule node, but does not add it to the tree.

This overload allows rule callbacks to be set.

Parameters
aRuleType	Rule type
aData	Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings.
aPreRule	Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its subtree.
aPostRule	The new rule node

Return Value: The new rule node

NewComponentL ( CBNFNode *, const TDesC & )

IMPORT_C CBNFNode *	NewComponentL	(	CBNFNode *	aRootRule,
			const TDesC &	aRuleName
		)

Creates a new reference rule node.

Parameters
aRootRule	Root node
aRuleName	Rule name

Return Value: The new reference rule node

NewComponentL ( CBNFNode &, TParserNodeTypes, const TDesC & )

IMPORT_C CBNFNode &	NewComponentL	(	CBNFNode &	aParentRule,
			TParserNodeTypes	aRuleType,
			const TDesC &	aData
		)

Creates a new sub-rule, and makes it a child of a specified parent rule.

This overload sets no rule callbacks.

Parameters
aParentRule	The rule to the new sub-rule shall be added as a child
aRuleType	Rule type
aData	Rule data reference. This is used with EExact and ESelect type rules to match actual text strings.

Return Value: The new sub-rule node

NewComponentL ( CBNFNode &, TParserNodeTypes, HBufC , TRuleCallback , TRuleCallback * )

IMPORT_C CBNFNode &	NewComponentL	(	CBNFNode &	aParentRule,
			TParserNodeTypes	aRuleType,
			HBufC *	aData = NULL,
			TRuleCallback *	aPreRule = NULL,
			TRuleCallback *	aPostRule = NULL
		)

Creates a new sub-rule, and makes it a child of a specified parent rule.

This overload sets rule callbacks.

Parameters
aParentRule	The rule to the new sub-rule shall be added as a child
aRuleType	Rule type
aData	Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings.
aPreRule	Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its subtree.
aPostRule	Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree.

Return Value: The new sub-rule node

NewComponentL ( CBNFNode *, CBNFNode &, const TDesC & )

IMPORT_C CBNFNode &	NewComponentL	(	CBNFNode *	aRootRule,
			CBNFNode &	aParentRule,
			const TDesC &	aRuleName
		)

Creates a new reference rule node, and adds it as a child of the specified parent.

Note that the function succeeds even if the target rule aRuleName does not yet exist.

Parameters
aRootRule	Root node: the function needs this to find the target rule identified by aRuleName
aParentRule	Parent rule to which to attach the new rule as a child
aRuleName	The name of the rule that the new node refers to

Return Value: The new reference rule node

NewL ( CAttributeLookupTable & )

IMPORT_C CBNFParser *

NewL

(

aLUT

)

[static]

Allocates and constructs a new BNF parser.

Parameters
aLUT	Attribute lookup table in which to store attributes for the rule tree

Return Value: New parser

NewRuleL ( CBNFNode , const TDesC &, TParserNodeTypes, HBufC , TRuleCallback , TRuleCallback )

IMPORT_C CBNFNode &	NewRuleL	(	CBNFNode *	aRootRule,
			const TDesC &	aRuleName,
			TParserNodeTypes	aRuleType,
			HBufC *	aData,
			TRuleCallback *	aPreRule,
			TRuleCallback *	aPostRule
		)

Creates a new rule node and adds it to the root of the rule tree.

This overload takes ownership of the node data.

Parameters
aRootRule	Pointer to the root BNF node, created with NewBNFL()
aRuleName	Reference to a string identifying this rule. The string is used to make references to this rule from other rule's subtrees.
aRuleType	Rule type
aData	Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings.
aPreRule	Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its children (i.e. the rule subtree).
aPostRule	Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree.

Return Value: The newly created rule node in the rule tree

NewRuleL ( CBNFNode , const TDesC &, TParserNodeTypes, const TDesC &, TRuleCallback , TRuleCallback * )

IMPORT_C CBNFNode &	NewRuleL	(	CBNFNode *	aRootRule,
			const TDesC &	aRuleName,
			TParserNodeTypes	aRuleType,
			const TDesC &	aData,
			TRuleCallback *	aPreRule,
			TRuleCallback *	aPostRule
		)

Creates a new rule node and adds it to the root of the rule tree.

This overload takes a reference to the node data instead of owning it.

Parameters
aRootRule	Pointer to the root BNF node, created with NewBNFL()
aRuleName	Reference to a string identifying this rule. The string is used to make references to this rule from other rule's subtrees.
aRuleType	Rule type
aData	Rule data pointer. This is used with EExact and ESelect type rules to match actual text strings.
aPreRule	Function pointer to a pre-rule function that gets called before the parser starts processing this rule and its children (i.e. the rule subtree).
aPostRule	Function pointer to a post-rule function that gets called after the parser has processed this rule and its subtree.

Return Value: The newly created rule node in the rule tree

OptionalL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	OptionalL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

OptionalMatched ( )

OptionalMatched

(

)

const [inline]

Tests if an Optional node sub-rule matched.

Return Value: True if the sub- rule matched; otherwise false

OrL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	OrL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an EOr rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

ParseL ( )

IMPORT_C TBool

ParseL

(

)

[protected]

PerformRuleL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	PerformRuleL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Handles a node in the rule tree.

It calls the appropriate handler method for the rule type.

Parameters
aRule	Rule node
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

ProcessDataL ( HBufC8 & )

IMPORT_C void

ProcessDataL

(

HBufC8 &

aData

)

[virtual]

Reimplemented from MDataProviderObserver::ProcessDataL(HBufC8 &)

Called by the data provider to add data for the parser to process.

This implements MDataProviderObserver::ProcessDataL().

Parameters
aData	The data to process

RangeL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	RangeL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an ERange rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

ReferenceL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	ReferenceL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes a reference rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

ResetL ( )

IMPORT_C void

ResetL

(

)

[virtual]

Reset the parser to a state where it can accept and parse new input.

If no BNF tree yet exists the virtual method TreeL() is called to obtain the BNF tree for this parser. Any existing state of parsing and input data is destroyed.

RuleMatched ( )

RuleMatched

(

)

const [inline]

Tests if the used rule matched.

This is typically used in post-rule callbacks.

Return Value: True if the used rule matched; otherwise false

SelectL ( CBNFNode &, CFragmentedString::TStringMatch & )

IMPORT_C TBool	SelectL	(	CBNFNode &	aRule,
			CFragmentedString::TStringMatch &	aMatched
		)	[protected, virtual]

Processes an ESelect rule node.

It is called by PerformRuleL().

Parameters
aRule	The rule node being processed
aMatched	On return, flag indicating if input stream matched the rule

Return Value: ETrue if the function completed processing this node, otherwise EFalse

SetAttributeLookupTable ( CAttributeLookupTable & )

void

SetAttributeLookupTable

(

aAttributeLookupTable

)

SetBaseUriL ( const TDesC * )

IMPORT_C void

SetBaseUriL

(

const TDesC *

aBaseUri

)

[virtual]

Reimplemented from MDataProviderObserver::SetBaseUriL(const TDesC *)

Intended Usage : Set the URI that the DataProvider considers the base URI for the current data.

Since: 6.0

Parameters
aBaseUri	A const pointer to the uri

SetDataExpected ( TInt )

IMPORT_C void

SetDataExpected

(

TInt

aAmountExpected

)

[virtual]

Reimplemented from MDataProviderObserver::SetDataExpected(TInt)

Intended Usage : The report of how many bytes of data is expected to be passed to ProcessDataL, enabling age reporting capabilities.

Since: 6.0

Parameters
aAmountExpected	An integer value of the expected amount

SetDocumentTypeL ( const TDesC & )

IMPORT_C void

SetDocumentTypeL

(

const TDesC &

aDataType

)

[virtual]

Reimplemented from MDataProviderObserver::SetDocumentTypeL(const TDesC &)

Intended Usage : The request to construct a CDataHandler to process data of aDataType, where aDataType is a string to match against some plugins declared data handling ability.

Since: 6.0

Parameters
aDataType	A reference to a descriptor with the data type

SetDocumentTypeL ( const TDesC &, const TDesC & )

IMPORT_C void	SetDocumentTypeL	(	const TDesC &	aDataType,
			const TDesC &	aContentType
		)	[virtual]

Reimplemented from MDataProviderObserver::SetDocumentTypeL(const TDesC &,const TDesC &)

Intended Usage : The request to construct a CDataHandler for aDataType with non default document encoding where aDataType is a string to match against some plugins declared data handling ability.

Since: 6.0

Parameters
aDataType	A reference to a descriptor with the data type
aContentType	A reference to a descriptor with the content type

SetState ( TParseState )

void

SetState

(

TParseState

aState

)

[protected, inline]

Sets the parser state.

Parameters
aState	Parser state

SetStatus ( TInt )

IMPORT_C void

SetStatus

(

TInt

aStatus = KErrNone

)

[virtual]

Reimplemented from MDataProviderObserver::SetStatus(TInt)

Called by the data provider to report its status to its observer.

This implements MDataProviderObserver::SetStatus().

Parameters
aStatus	Status code

StartConditional ( TParserNodeTypes )

IMPORT_C void

StartConditional

(

TParserNodeTypes

aRuleType

)

[protected, virtual]

State ( )

TParseState

State

(

)

const [inline]

Get the current state of the parser.

Return Value: Parser state

StringL ( )

HBufC *

StringL

(

)

const [inline]

Concatenates the rest of the input stream (which hasn't yet been processed) into a single string. The ownership of the string is given to the caller.

Return Value: String containing the remaining data to be parsed. OWNERSHIP PASSED TO CALLED.

TreeL ( )

IMPORT_C CBNFNode *

TreeL

(

)

[protected, virtual]

Valid ( )