/// <summary>
/// Evaluate the expression, returning the result as an <c>XdmValue</c> (that is,
/// a sequence of nodes and/or atomic values).
/// </summary>
/// <remarks>
/// Although a singleton result <i>may</i> be represented as an <c>XdmItem</c>, there is
/// no guarantee that this will always be the case. If you know that the expression will return at
/// most one node or atomic value, it is best to use the <c>EvaluateSingle</c> method, which
/// does guarantee that an <c>XdmItem</c> (or null) will be returned.
/// </remarks>
/// <returns>
/// An <c>XdmValue</c> representing the results of the expression.
/// </returns>
/// <exception cref="DynamicError">
/// Throws <c>Saxon.Api.DynamicError</c> if the evaluation of the XPath expression fails
/// with a dynamic error.
/// </exception>
public XdmValue Evaluate()
{
try {
JSequence value = (JSequence)JSequenceExtent.makeSequenceExtent(
exp.iterate(dynamicContext));
return(XdmValue.Wrap(value));
} catch (net.sf.saxon.trans.XPathException err) {
throw new DynamicError(err);
}
}
/// <summary>
/// Call a global user-defined function in the compiled query.
/// </summary>
/// <remarks>
/// If this is called more than once (to evaluate the same function repeatedly with different arguments,
/// or to evaluate different functions) then the sequence of evaluations uses the same values of global
/// variables including external variables (query parameters); the effect of any changes made to query parameters
/// between calls is undefined.
/// </remarks>
/// <param name="function">
/// The name of the function to be called
/// </param>
/// <param name="arguments">
/// The values of the arguments to be supplied to the function. These
/// must be of the correct type as defined in the function signature (there is no automatic
/// conversion to the required type).
/// </param>
/// <exception cref="ArgumentException">If no function has been defined with the given name and arity
/// or if any of the arguments does not match its required type according to the function
/// signature.</exception>
/// <exception cref="DynamicError">If a dynamic error occurs in evaluating the function.
/// </exception>
public XdmValue CallFunction(QName function, XdmValue[] arguments)
{
try {
JXdmValue[] vr = new JXdmValue[arguments.Length];
for (int i = 0; i < arguments.Length; i++)
{
vr[i] = XdmValue.FromGroundedValueToJXdmValue(arguments[i].value);
}
JSequence result = evaluator.callFunction(function.UnderlyingQName(), vr).getUnderlyingValue();
return(XdmValue.Wrap(result));
} catch (JSaxonApiException e) {
throw new DynamicError(e);
}
}
///<summary>
/// Call a global user-defined function in the compiled query.
///</summary>
///<remarks>
/// If this is called more than once (to evaluate the same function repeatedly with different arguments,
/// or to evaluate different functions) then the sequence of evaluations uses the same values of global
/// variables including external variables (query parameters); the effect of any changes made to query parameters
/// between calls is undefined.
/// </remarks>
/// <param name="function">
/// The name of the function to be called
/// </param>
/// <param name="arguments">
/// The values of the arguments to be supplied to the function. These
/// must be of the correct type as defined in the function signature (there is no automatic
/// conversion to the required type).
/// </param>
/// <exception cref="ArgumentException">If no function has been defined with the given name and arity
/// or if any of the arguments does not match its required type according to the function
/// signature.</exception>
/// <exception cref="DynamicError">If a dynamic error occurs in evaluating the function.
/// </exception>
public XdmValue CallFunction(QName function, XdmValue[] arguments)
{
JUserFunction fn = exp.getMainModule().getUserDefinedFunction(
function.Uri, function.LocalName, arguments.Length);
if (fn == null)
{
throw new ArgumentException("No function with name " + function.ClarkName +
" and arity " + arguments.Length + " has been declared in the query");
}
try {
// TODO: use the same controller in other interfaces such as run(), and expose it in a trapdoor API
if (controller == null)
{
controller = exp.newController(context);
context.initializeController(controller);
controller.initializeController(context.getParameters());
}
JSequence[] vr = new JSequence[arguments.Length];
for (int i = 0; i < arguments.Length; i++)
{
JSequenceType type = fn.getParameterDefinitions()[i].getRequiredType();
vr[i] = arguments[i].Unwrap();
if (!type.matches(vr[i], controller.getConfiguration().getTypeHierarchy()))
{
throw new ArgumentException("Argument " + (i + 1) +
" of function " + function.ClarkName +
" does not match the required type " + type.toString());
}
}
JSequence result = fn.call(vr, controller);
return(XdmValue.Wrap(result));
} catch (JXPathException e) {
throw new DynamicError(e);
}
}
