CustomXmlPart.Id property

Gets or sets the string that identifies this custom XML part within an OOXML document.

public string Id { get; set; }


ISO/IEC 29500 specifies that this value is a GUID, but old versions of Microsoft Word allowed any string here. Aspose.Words does the same for ECMA-376 format. But note, that Microsoft Word Online fails to open a document created with a non-GUID value. So, a GUID is preferred value for this property.

A valid value must be an identifier that is unique among all custom XML data parts in this document.

The default value is an empty string. The value cannot be null.


Shows how to create a structured document tag with custom XML data.

Document doc = new Document();

// Construct an XML part that contains data and add it to the document's collection.
// If we enable the "Developer" tab in Microsoft Word,
// we can find elements from this collection in the "XML Mapping Pane", along with a few default elements.
string xmlPartId = Guid.NewGuid().ToString("B");
string xmlPartContent = "<root><text>Hello world!</text></root>";
CustomXmlPart xmlPart = doc.CustomXmlParts.Add(xmlPartId, xmlPartContent);

Assert.AreEqual(Encoding.ASCII.GetBytes(xmlPartContent), xmlPart.Data);
Assert.AreEqual(xmlPartId, xmlPart.Id);

// Below are two ways to refer to XML parts.
// 1 -  By an index in the custom XML part collection:
Assert.AreEqual(xmlPart, doc.CustomXmlParts[0]);

// 2 -  By GUID:
Assert.AreEqual(xmlPart, doc.CustomXmlParts.GetById(xmlPartId));

// Add an XML schema association.

// Clone a part, and then insert it into the collection.
CustomXmlPart xmlPartClone = xmlPart.Clone();
xmlPartClone.Id = Guid.NewGuid().ToString("B");

Assert.AreEqual(2, doc.CustomXmlParts.Count);

// Iterate through the collection and print the contents of each part.
using (IEnumerator<CustomXmlPart> enumerator = doc.CustomXmlParts.GetEnumerator())
    int index = 0;
    while (enumerator.MoveNext())
        Console.WriteLine($"XML part index {index}, ID: {enumerator.Current.Id}");
        Console.WriteLine($"\tContent: {Encoding.UTF8.GetString(enumerator.Current.Data)}");

// Use the "RemoveAt" method to remove the cloned part by index.

Assert.AreEqual(1, doc.CustomXmlParts.Count);

// Clone the XML parts collection, and then use the "Clear" method to remove all its elements at once.
CustomXmlPartCollection customXmlParts = doc.CustomXmlParts.Clone();

// Create a structured document tag that will display our part's contents and insert it into the document body.
StructuredDocumentTag tag = new StructuredDocumentTag(doc, SdtType.PlainText, MarkupLevel.Block);
tag.XmlMapping.SetMapping(xmlPart, "/root[1]/text[1]", string.Empty);


doc.Save(ArtifactsDir + "StructuredDocumentTag.CustomXml.docx");

See Also