/// <summary>
/// Constructor with optionsl initial values. If <code>propName</code> is provided,
/// <code>schemaNs</code> has also be provided. </summary>
/// <param name="xmp"> the iterated metadata object. </param>
/// <param name="schemaNs"> the iteration is reduced to this schema (optional) </param>
/// <param name="propPath"> the iteration is redurce to this property within the <code>schemaNs</code> </param>
/// <param name="options"> advanced iteration options, see <seealso cref="IteratorOptions"/> </param>
/// <exception cref="XmpException"> If the node defined by the paramters is not existing. </exception>
public XmpIteratorImpl(XmpMetaImpl xmp, string schemaNs, string propPath, IteratorOptions options) {
// make sure that options is defined at least with defaults
_options = options ?? new IteratorOptions();
// the start node of the iteration depending on the schema and property filter
XmpNode startNode;
string initialPath = null;
bool baseSchema = !String.IsNullOrEmpty(schemaNs);
bool baseProperty = !String.IsNullOrEmpty(propPath);
if (!baseSchema && !baseProperty) {
// complete tree will be iterated
startNode = xmp.Root;
}
else if (baseSchema && baseProperty) {
// Schema and property node provided
XmpPath path = XmpPathParser.ExpandXPath(schemaNs, propPath);
// base path is the prop path without the property leaf
XmpPath basePath = new XmpPath();
for (int i = 0; i < path.Size() - 1; i++) {
basePath.Add(path.GetSegment(i));
}
startNode = XmpNodeUtils.FindNode(xmp.Root, path, false, null);
_baseNs = schemaNs;
initialPath = basePath.ToString();
}
else if (baseSchema && !baseProperty) {
// Only Schema provided
startNode = XmpNodeUtils.FindSchemaNode(xmp.Root, schemaNs, false);
}
else // !baseSchema && baseProperty
{
// No schema but property provided -> error
throw new XmpException("Schema namespace URI is required", XmpError.BADSCHEMA);
}
// create iterator
if (startNode != null) {
_nodeIterator = (!_options.JustChildren)
? new NodeIterator(this, startNode, initialPath, 1)
: new NodeIteratorChildren(this, startNode, initialPath);
}
else {
// create null iterator
_nodeIterator = EmptyList.GetEnumerator();
}
}
/// <seealso cref= XMPMeta#iterator(String, String, IteratorOptions) </seealso>
public virtual IXmpIterator Iterator(string schemaNs, string propName, IteratorOptions options) {
return new XmpIteratorImpl(this, schemaNs, propName, options);
}
/// <seealso cref= XMPMeta#iterator(IteratorOptions) </seealso>
public virtual IXmpIterator Iterator(IteratorOptions options) {
return Iterator(null, null, options);
}
