ExpressionEval.EvalXML
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Use this method to evaluate an expression represented as an Extensible Markup Language (XML) fragment.
Definition
Function EvalXML(bstrXMLExpr As String,DictObjs As Object) As Variant
Parameters
btrXMLExpr
[in] A String that contains the XML fragment to be evaluated.
DictObjs
[in] A Dictionary object that contains a set of profiles.
Return Values
This method returns a Variant indicating the results of evaluating the expression in the specified context. This result may be True, False, or Nothing. Nothing indicates the expression could not be evaluated.
Error Values
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 | &H81100018 | Argument datatype information missing from expression, or unrecognized argument data type encountered in expression |
| E_EXPR_BADARGVALUE | &H81100022 | Invalid expression argument value, or impossible conversion |
| E_EXPR_BADCLAUSE | &H81100016 | Invalid clause encountered |
| E_EXPR_BADCONNECTION | &H8110001F | Invalid connection |
| E_EXPR_BADOPER | &H81100017 | Operator missing, unrecognized operator encountered, or type mismatch |
| E_EXPR_BADTERM | &H81100015 | Term type missing, or unrecognized term type encountered |
| E_EXPR_BADXML | &H81100014 | An unrecognized XML element was encountered |
| E_EXPR_NOCONNECTIONSTRING | &H8110000D | No connection string specified |
| E_EXPR_XMLPARSE | &H81100013 | XML DOM object parsing error |
Additional information may be available using the global Err object. In particular, the Description property may contain a text description of the error.
Remarks
The XML is parsed before being evaluated. For information on the XML format, see Expression XML Structures.
Expressions evaluated with the EvalXML method are not persistent; that is, they are not stored in the expression store or loaded into the expression cache. Use the Eval method to evaluate persistent expressions.
A new ExprEvalContext object is created and then discarded for each XML fragment that is evaluated.
The Connect method must be called before using the EvalXML method.
For more information about memory ownership issues related to COM property and method parameters, see Managing COM Parameter Memory.
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>"
' vResult is a Variant
' dictProfiles is a Dictionary object containing a set of profiles
vResult = oExpressionEval.EvalXML(sXMLExpr, dictProfiles)