/// <summary>
/// Instantiates a reader object for the given XML PrintCapabilities
/// </summary>
/// <remarks>Constructor verifies the root element is valid</remarks>
/// <exception cref="FormatException">thrown if XML PrintCapabilities is not well-formed</exception>
public XmlPrintCapReader(Stream xmlStream)
{
// Internally the XML PrintCapabilities reader uses XmlTextReader
_xmlReader = new XmlTextReader(xmlStream);
// We need namespace support from the reader.
_xmlReader.Namespaces = true;
// Don't resolve external resources.
_xmlReader.XmlResolver = null;
// Verify root element is <PrintCapabilities> in our standard namespace
if ((_xmlReader.MoveToContent() != XmlNodeType.Element) ||
(_xmlReader.LocalName != PrintSchemaTags.Framework.PrintCapRoot) ||
(_xmlReader.NamespaceURI != PrintSchemaNamespaces.Framework))
{
throw NewPrintCapFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.InvalidRootElement"),
_xmlReader.NamespaceURI,
_xmlReader.LocalName));
}
// Verify the XML PrintCapabilities version is supported
// For XML attribute without a prefix (e.g. <... name="prn:PageMediaSize">),
// even though the XML document has default namespace defined as our standard
// Print Schema framework namespace, the XML atribute still has NULL namespaceURI.
// It will only have the correct namespaceURI when a prefix is used. This doesn't
// apply to XML element, whose namespaceURI works fine with default namespace.
// GetAttribute doesn't move the reader cursor away from the current element
string version = _xmlReader.GetAttribute(PrintSchemaTags.Framework.RootVersionAttr,
PrintSchemaNamespaces.FrameworkAttrForXmlReader);
if (version == null)
{
throw NewPrintCapFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootMissingAttribute"),
PrintSchemaTags.Framework.RootVersionAttr));
}
// Convert string to number to verify
decimal versionNum;
try
{
versionNum = XmlConvertHelper.ConvertStringToDecimal(version);
}
catch (FormatException e)
{
throw NewPrintCapFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootInvalidAttribute"),
PrintSchemaTags.Framework.RootVersionAttr,
version),
e);
}
if (versionNum != PrintSchemaTags.Framework.SchemaVersion)
{
throw NewPrintCapFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.VersionNotSupported"),
versionNum));
}
// Reset internal states to be ready for client's reading of the PrintCapabilities XML
ResetCurrentElementState();
}
/// <summary>
/// Verifies if the PrintTicket is well-formed
/// </summary>
/// <exception cref="FormatException">
/// The PrintTicket is not well-formed.
/// </exception>
public static void CheckIsWellFormedPrintTicket(InternalPrintTicket pt)
{
XmlElement root = pt.XmlDoc.DocumentElement;
// Root element should be in our standard namespace and should be <PrintTicket>.
if ((root.NamespaceURI != PrintSchemaNamespaces.Framework) ||
(root.LocalName != PrintSchemaTags.Framework.PrintTicketRoot))
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.InvalidRootElement"),
root.NamespaceURI,
root.LocalName));
}
string version = root.GetAttribute(PrintSchemaTags.Framework.RootVersionAttr,
PrintSchemaNamespaces.FrameworkAttrForXmlDOM);
// Root element should have the "version" attribute
// (XmlElement.GetAttribute returns empty string when the attribute is not found, but
// (XmlTextReader.GetAttribute returns null when the attribute is not found)
if ((version == null) || (version.Length == 0))
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootMissingAttribute"),
PrintSchemaTags.Framework.RootVersionAttr));
}
decimal versionNum;
try
{
versionNum = XmlConvertHelper.ConvertStringToDecimal(version);
}
catch (FormatException e)
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootInvalidAttribute"),
PrintSchemaTags.Framework.RootVersionAttr,
version),
e);
}
// and the "version" attribute value should be what we support
if (versionNum != PrintSchemaTags.Framework.SchemaVersion)
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.VersionNotSupported"),
versionNum));
}
// Now go through each root child element and verify they are valid children
XmlNode rootChild = root.FirstChild;
// It's recommended that traversing the node in forward-only movement by using NextSibling
// is best for XmlDocument performance. This is because the list is not double-linked.
while (rootChild != null)
{
// If the root child doesn't live in our standard namespace, we should ignore it
// rather than rejecting it since it's acceptable to have private elements under
// the root.
if (rootChild.NamespaceURI == PrintSchemaNamespaces.Framework)
{
// For <PrintTicket> root, our Framework schema only allow these children elements:
// <Feature> <AttributeSet> <Property> <ParameterInit>
if ((rootChild.NodeType != XmlNodeType.Element) ||
((rootChild.LocalName != PrintSchemaTags.Framework.Feature) &&
(rootChild.LocalName != PrintSchemaTags.Framework.ParameterInit) &&
(rootChild.LocalName != PrintSchemaTags.Framework.Property)))
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootInvalidChildElement"),
rootChild.Name));
}
string childName = ((XmlElement)rootChild).GetAttribute(PrintSchemaTags.Framework.NameAttr,
PrintSchemaNamespaces.FrameworkAttrForXmlDOM);
// All the recognized root child element should have an XML attribut "name"
if ((childName == null) || (childName.Length == 0))
{
throw NewPTFormatException(String.Format(CultureInfo.CurrentCulture,
PTUtility.GetTextFromResource("FormatException.RootChildMissingAttribute"),
rootChild.Name,
PrintSchemaTags.Framework.NameAttr));
}
}
rootChild = rootChild.NextSibling;
}
// We will end the verification at the root child level here. Instead of traversing the whole tree
// to find violations in this construtor, we will delay detecting violations under root child level
// until information of an individual feature/property subtree is requested.
}