## CustomXmlPart class

Represents a Custom XML Data Storage Part (custom XML data within a package).
To learn more, visit the [Structured Document Tags or Content Control](https://docs.aspose.com/words/nodejs-net/working-with-content-control-sdt/) documentation article.




### Remarks

A DOCX or DOC document can contain one or more Custom XML Data Storage parts. Aspose.Words preserves and 
allows to create and extract Custom XML Data via the [Document.customXmlParts](../../aspose.words/document/customXmlParts/) collection.




### Constructors
| Name | Description |
| --- | --- |
| [CustomXmlPart()](./constructor/#default) | The default constructor. |

### Properties

| Name | Description |
| --- | --- |
| [data](./data/) | Gets or sets the XML content of this Custom XML Data Storage Part. |
| [dataChecksum](./dataChecksum/) | Specifies a cyclic redundancy check (CRC) checksum of the [CustomXmlPart.data](./data/) content. |
| [id](./id/) | Gets or sets the string that identifies this custom XML part within an OOXML document. |
| [schemas](./schemas/) | Specifies the set of XML schemas that are associated with this custom XML part. |

### Methods

| Name | Description |
| --- | --- |
|[ clone()](./clone/#default) | Makes a "deep enough" copy of the object.  Does not duplicate the bytes of the [CustomXmlPart.data](./data/) value. |

### Examples

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

```js
let doc = new aw.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.
let xmlPartId = `{${Guid.newGuid().toString()}}`;
let xmlPartContent = "<root><text>Hello world!</text></root>";
let xmlPart = doc.customXmlParts.add(xmlPartId, xmlPartContent);

expect(Buffer.from(xmlPart.data).toString("ascii")).toEqual(xmlPartContent);
expect(xmlPart.id).toEqual(xmlPartId);

// Below are two ways to refer to XML parts.
// 1 -  By an index in the custom XML part collection:
expect(doc.customXmlParts.at(0)).toEqual(xmlPart);

// 2 -  By GUID:
expect(doc.customXmlParts.getById(xmlPartId)).toEqual(xmlPart);

// Add an XML schema association.
xmlPart.schemas.add("http://www.w3.org/2001/XMLSchema");

// Clone a part, and then insert it into the collection.
let xmlPartClone = xmlPart.clone();
xmlPartClone.id = `{${Guid.newGuid().toString()}}`;
doc.customXmlParts.add(xmlPartClone);

expect(doc.customXmlParts.count).toEqual(2);

// Iterate through the collection and print the contents of each part.
for (let index = 0; index < doc.customXmlParts.count; ++index) {
  console.log(`XML part index ${index}, ID: ${doc.customXmlParts.at(index).id}`);
  console.log(`\tContent: ${Buffer.from(doc.customXmlParts.at(index).data).toString("utf8")}`);
}

// Use the "RemoveAt" method to remove the cloned part by index.
doc.customXmlParts.removeAt(1);

expect(doc.customXmlParts.count).toEqual(1);

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

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

doc.firstSection.body.appendChild(tag);

doc.save(base.artifactsDir + "StructuredDocumentTag.customXml.docx");
```

### See Also

* module [Aspose.Words.Markup](../)
* property [Document.customXmlParts](../../aspose.words/document/customXmlParts/)
* class [CustomXmlPartCollection](../customxmlpartcollection/)