IExpressionEval::ParseXML Method
Use this method to check whether an Extensible Markup Language (XML) fragment is a syntactically correct expression.
HRESULT IExpressionEval::ParseXML(
BSTR bstrXMLExpr,
VARIANT_BOOL* pbValid
);
Function ParseXML(
bstrXMLExpr As String
) As Boolean
Parameters
bstrXMLExpr
[C++][in] A BSTR that contains the XML text defining an expression.
[Visual Basic]
A String that contains the XML text defining an expression.
pbValid
[out, retval] A pointer to a VARIANT_BOOL indicating the validity of the expression.
Return Value
[C++]
This method returns an HRESULT indicating whether it completed successfully. See the Error Values section for more details.
[Visual Basic]
This method returns a Boolean value indicating the results of parsing the expression (bstrXMLExpr).
Error Values
[C++]
This method returns S_OK (0x00000000) to indicate success and either standard or custom COM HRESULT error values to indicate failure. For more information about standard COM errors, see Standard COM Errors.
[Visual Basic]
This method sets the Number property of the global Err object to S_OK (&H00000000) to indicate success and to either standard or custom COM error values to indicate failure. For more information about standard COM errors, see Standard COM Errors.
The following table shows the custom COM errors that this method can return.
Constant |
Value |
Description |
|---|---|---|
E_EXPR_BADARGTYPE |
0x81100018 |
Argument data type information missing from expression, or unrecognized argument data type encountered in expression |
E_EXPR_BADARGVALUE |
0x81100022 |
Invalid expression argument value, or impossible conversion |
E_EXPR_BADCLAUSE |
0x81100016 |
Invalid clause encountered |
E_EXPR_BADOPER |
0x81100017 |
Operator missing, unrecognized operator encountered, or type mismatch |
E_EXPR_BADTERM |
0x81100015 |
Term type missing, or unrecognized term type encountered |
E_EXPR_BADXML |
0x81100014 |
An unrecognized XML element was encountered |
E_EXPR_XMLPARSE |
0x81100013 |
XML DOM object parsing error |
[C++]
Additional information may be available using the global Err object, which can be accessed using the API function GetErrorInfo. In particular, the GetDescription method of the IErrorInfo interface may return a text description of the error.
[Visual Basic]
Additional information may be available using the global Err object. In particular, the Description property may contain a text description of the error.
Remarks
Since this method only checks syntax, the expression may still be invalid even though the method succeeds.
The expression store is not used for XML fragments.
The pbValid parameter contains valid data only if the method completes successfully.
Example
' sXMLExpr is a string.
' Note that this string is not formatted properly with respect to
' quotation marks or continuation in order to increase readability.
strXMLExpr = "<CLAUSE OPER="equal">
<PROPERTY ID="User.firstName" TYPE="string" />
<IMMED-VAL TYPE="string">Jill</IMMED-VAL>
</CLAUSE>"
' bResult is a Boolean.
bResult = oExpressionEval.ParseXML(sXMLExpr)