EvalValue

Collaboration diagram for EvalValue:

Detailed Description

Classes
struct	IEvalValue
	Dynamic expression evaluator. More...
class	EvalValuePtr
	Dynamic expression evaluator. More...

Functions
daq::StringPtr	getEval () const
	Gets the expression. More...
daq::BaseObjectPtr	getResult () const
	Gets the result of the expression. More...
daq::EvalValuePtr	cloneWithOwner (const daq::PropertyObjectPtr &owner) const
	Clones the object and attaches an owner. More...
void	getParseErrorCode () const
	Returns the parse error code. More...
daq::ListPtr< daq::IString >	getPropertyReferences () const
	Returns the names of all properties referenced by the eval value. More...

Function Documentation

cloneWithOwner()

daq::EvalValuePtr cloneWithOwner ( const daq::PropertyObjectPtr &  owner ) const

inline

Clones the object and attaches an owner.

Parameters

owner

The owner to attach to the cloned eval value.

Returns

The cloned object.

When the expression contains reference to some property object, then the expression cannot be evaluated unless an owner is attached to eval value. However, the object can be cloned with the specified owner attached. The client can then evaluate the cloned object.

getEval()

daq::StringPtr getEval ( ) const

inline

Gets the expression.

Returns

The expression.

Expression is passed as a parameter to the factory function.

getParseErrorCode()

void getParseErrorCode ( ) const

inline

Returns the parse error code.

When an eval value object is created, the expression is passed as an argument to the factory function. Parsing of the expression can fail, but the factory function will always succeed. Use this function to check if the parsing of the expression succeeded without evaluating the expression.

getPropertyReferences()

daq::ListPtr<daq::IString> getPropertyReferences ( ) const

inline

Returns the names of all properties referenced by the eval value.

Returns

The names of referenced properties.

Referenced properties are all occurrences matching the '"%" propref' pattern in the evaluation string.

getResult()

daq::BaseObjectPtr getResult ( ) const

inline

Gets the result of the expression.

Returns

The result of the expression.

Exceptions

CalcFailedException	when calculation failed.
OpendaqErrException	when reference resolution failed
ParseFailedException	when expression parsing failed

When this method is called for the first time, the object will trigger execution and return result.