IValidator Struct Reference

Used by openDAQ properties to validate whether a value fits the value restrictions of the Property. More...

Inheritance diagram for IValidator:

Collaboration diagram for IValidator:

Detailed Description

Used by openDAQ properties to validate whether a value fits the value restrictions of the Property.

Whenever a value is set to on a Property object, if the corresponding Property has a validator configured, the value will be validated, throwing a validation error, if the value is not compliant with the validation restrictions. For example, a validator can check the written value for lower-than, greater-than, equality, or other number relations.

The validation conditions are configured with an evaluation string when the validator is constructed. The string constructs an Eval value that replaces any instance of the keyword "value" or "val" with the value being set. The result of the Eval value evaluation is the output of the validate function call. For example, validators created with the string "value == 5" would reject any value that is not equal to 5.

Public Member Functions
virtual ErrCode INTERFACE_FUNC	validate (IBaseObject *propObj, IBaseObject *value)=0
	Checks whether value adheres to the validity conditions of the validator. More...
virtual ErrCode INTERFACE_FUNC	getEval (IString **eval)=0
	Gets the string expression used when creating the validator. More...
Public Member Functions inherited from IBaseObject
virtual ErrCode INTERFACE_FUNC	borrowInterface (const IntfID &intfID, void **obj) const =0
	Returns another interface which is supported by the object without incrementing the reference count. More...
virtual ErrCode INTERFACE_FUNC	dispose ()=0
	Disposes all references held by the object. More...
virtual ErrCode INTERFACE_FUNC	getHashCode (SizeT *hashCode)=0
	Returns hash code of the object. More...
virtual ErrCode INTERFACE_FUNC	equals (IBaseObject *other, Bool *equal) const =0
	Compares object to another object for equality. More...
virtual ErrCode INTERFACE_FUNC	toString (CharPtr *str)=0
	Returns a string representation of the object. More...
Public Member Functions inherited from IUnknown
virtual ErrCode INTERFACE_FUNC	queryInterface (const IntfID &intfID, void **obj)=0
	Returns another interface which is supported by the object and increments the reference count. More...
virtual int INTERFACE_FUNC	addRef ()=0
	Increments the reference count for an interface on an object. More...
virtual int INTERFACE_FUNC	releaseRef ()=0
	Decrements the reference count for an interface on an object. More...

Member Function Documentation

getEval()

virtual ErrCode INTERFACE_FUNC getEval ( IString **  eval )

pure virtual

Gets the string expression used when creating the validator.

Parameters

[out]

eval

The validation expression.

validate()

virtual ErrCode INTERFACE_FUNC validate ( IBaseObject *  propObj, IBaseObject *  value  )

pure virtual

Checks whether value adheres to the validity conditions of the validator.

Parameters

propObj	Optional property object parameter required if the validation depends on other properties of the Property object.
value	The value to be checked for whether it is valid or not.

Return values

OPENDAQ_ERR_VALIDATE_FAILED	if value is invalid.
OPENDAQ_SUCCESS	if value is valid.