/// <summary>Visit all of the top level nodes looking for aliases.</summary>
/// <remarks>
/// Visit all of the top level nodes looking for aliases. If there is
/// no base, transplant the alias subtree. If there is a base and strict
/// aliasing is on, make sure the alias and base subtrees match.
/// </remarks>
/// <param name="tree">the root of the metadata tree</param>
/// <param name="options">th parsing options</param>
/// <exception cref="XmpException">Forwards XMP errors</exception>
private static void MoveExplicitAliases(XmpNode tree, ParseOptions options)
{
if (!tree.HasAliases)
{
return;
}
tree.HasAliases = false;
var strictAliasing = options.StrictAliasing;
for (var schemaIt = tree.GetUnmodifiableChildren().Iterator(); schemaIt.HasNext();)
{
var currSchema = (XmpNode)schemaIt.Next();
if (!currSchema.HasAliases)
{
continue;
}
for (var propertyIt = currSchema.IterateChildren(); propertyIt.HasNext();)
{
var currProp = (XmpNode)propertyIt.Next();
if (!currProp.IsAlias)
{
continue;
}
currProp.IsAlias = false;
// Find the base path, look for the base schema and root node.
var info = XmpMetaFactory.SchemaRegistry.FindAlias(currProp.Name);
if (info != null)
{
// find or create schema
var baseSchema = XmpNodeUtils.FindSchemaNode(tree, info.Namespace, null, true);
baseSchema.IsImplicit = false;
var baseNode = XmpNodeUtils.FindChildNode(baseSchema, info.Prefix + info.PropName, false);
if (baseNode == null)
{
if (info.AliasForm.IsSimple())
{
// A top-to-top alias, transplant the property.
// change the alias property name to the base name
var qname = info.Prefix + info.PropName;
currProp.Name = qname;
baseSchema.AddChild(currProp);
// remove the alias property
propertyIt.Remove();
}
else
{
// An alias to an array item,
// create the array and transplant the property.
baseNode = new XmpNode(info.Prefix + info.PropName, info.AliasForm.ToPropertyOptions());
baseSchema.AddChild(baseNode);
TransplantArrayItemAlias(propertyIt, currProp, baseNode);
}
}
else if (info.AliasForm.IsSimple())
{
// The base node does exist and this is a top-to-top alias.
// Check for conflicts if strict aliasing is on.
// Remove and delete the alias subtree.
if (strictAliasing)
{
CompareAliasedSubtrees(currProp, baseNode, true);
}
propertyIt.Remove();
}
else
{
// This is an alias to an array item and the array exists.
// Look for the aliased item.
// Then transplant or check & delete as appropriate.
XmpNode itemNode = null;
if (info.AliasForm.IsArrayAltText)
{
var xdIndex = XmpNodeUtils.LookupLanguageItem(baseNode, XmpConstants.XDefault);
if (xdIndex != -1)
{
itemNode = baseNode.GetChild(xdIndex);
}
}
else if (baseNode.HasChildren)
{
itemNode = baseNode.GetChild(1);
}
if (itemNode == null)
{
TransplantArrayItemAlias(propertyIt, currProp, baseNode);
}
else if (strictAliasing)
{
CompareAliasedSubtrees(currProp, itemNode, true);
}
propertyIt.Remove();
}
}
}
currSchema.HasAliases = false;
}
}