/// <summary>
/// Gets the specified attribute values for the specified scanner.
/// </summary>
/// <param name="scannerService"></param>
/// <param name="scannerId"></param>
/// <param name="attributes"></param>
/// <returns></returns>
public static IObservable <IReadOnlyCollection <AttributeInfo> > GetAttributeValuesAsync(
this ICoreScannerService scannerService,
Int32 scannerId,
params AttributeId[] attributes)
{
Contract.Requires(scannerService != null);
Contract.Requires(scannerId > 0);
Contract.Requires(attributes.Length > 0);
XDocument inXml = new XDocument(
new XElement("inArgs",
new XElement("scannerID", scannerId),
new XElement("cmdArgs",
new XElement("arg-xml",
new XElement("attrib_list", attributes.Cast <Int32>().ToArray())))));
IObservable <IReadOnlyCollection <AttributeInfo> > resultAsync = scannerService
.WhenCommandResponded()
.Do(e => e.Status.ThrowIfError())
.SelectMany(e => e.OutXml
.ParseXmlDocument()
.Elements("outArgs"))
.Where(outXml => outXml
.Elements("scannerID")
.All(e => e.Value.ToInt32().Equals(scannerId)))
.SelectMany(outXml => outXml
.Elements("arg-xml")
.Elements("response"))
.Where(response => response
.Elements("opcode")
.Select(e => (OperationCode)e.Value.ToInt32())
.All(opCode => opCode.Equals(OperationCode.GetAttribute)))
.FirstAsync()
.RunAsync(CancellationToken.None)
.Select(outXml => outXml
.Elements("attrib_list")
.Elements("attribute")
.Select(e => AttributeInfo.Parse(e.ToString()))
.ToList()
.AsReadOnly());
scannerService
.ExecuteCommandAsync(OperationCode.GetAttribute, inXml.ToString());
return(resultAsync);
}
/// <summary>
/// Gets the next attribute value of the specified attribute for the specified scanner.
/// </summary>
/// <param name="scannerService"></param>
/// <param name="scannerId"></param>
/// <param name="attribute"></param>
/// <returns></returns>
/// <remarks>
/// Can be used to create an asynchronous scanner attribute iterator.
/// </remarks>
public static IObservable <AttributeInfo> GetNextAttributeValueAsync(
this ICoreScannerService scannerService,
Int32 scannerId,
AttributeId attributeId)
{
Contract.Requires(scannerService != null);
Contract.Requires(scannerId > 0);
XDocument inXml = new XDocument(
new XElement("inArgs",
new XElement("scannerID", scannerId),
new XElement("cmdArgs",
new XElement("arg-xml",
new XElement("attrib_list", (Int32)attributeId)))));
IObservable <AttributeInfo> resultAsync = scannerService
.WhenCommandResponded()
.Do(e => e.Status.ThrowIfError())
.SelectMany(e => e.OutXml
.ParseXmlDocument()
.Elements("outArgs"))
.Where(outArgs => outArgs
.Elements("scannerID")
.All(e => e.Value.ToInt32().Equals(scannerId)))
.SelectMany(outArgs => outArgs
.Elements("arg-xml")
.Elements("response"))
.Where(response => response
.Elements("opcode")
.Select(opCode => (OperationCode)opCode.Value.ToInt32())
.All(opCode => opCode.Equals(OperationCode.GetNextAttribute)))
.FirstAsync()
.RunAsync(CancellationToken.None)
.SelectMany(response => response
.Elements("attrib_list")
.Elements("attribute")
.Select(attribute => AttributeInfo.Parse(attribute.ToString())));
scannerService
.ExecuteCommandAsync(OperationCode.GetNextAttribute, inXml.ToString());
return(resultAsync);
}