## ASP.NET XML Control: DocumentSource Property
The `DocumentSource` property is a key property of the ASP.NET `Xml` web control. It is used to specify or retrieve the path to the XML document that you want to display or manipulate within the control.
---
## Definition and Usage
The `DocumentSource` property binds an external XML file to the `
` control. When the page renders, the control loads the XML content from the specified path and outputs it directly to the page (or transforms it first if a stylesheet is applied via the `TransformSource` property).
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## Syntax
```xml
```
### Property Values
| Property Value | Description |
| :--- | :--- |
| `path` | A string value specifying the location of the XML file.
**Supported Path Types:**
• **Relative Path:** Relative to the location of the current page (e.g., `"~/App_Data/note.xml"` or `"note.xml"`).
• **Absolute Path:** A physical path on the server (e.g., `"C:\xml\note.xml"`). |
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## Code Example
The following example demonstrates how to load and display an external XML file named `note.xml` using the `DocumentSource` property.
### The XML File (`note.xml`)
```xml
Tove
Jani
Reminder
Don't forget me this weekend!
```
### The ASPX Page
```html
<%@ Page Language="C#" %>
ASP.NET Xml DocumentSource Example
```
---
## Important Considerations
1. **Path Resolution:**
Using the tilde operator (`~/`) is highly recommended for web applications. It represents the root directory of the application, ensuring that paths resolve correctly even if the page is moved to a different subfolder (e.g., `DocumentSource="~/App_Data/note.xml"`).
2. **Alternative Properties:**
* If your XML data is stored in a string variable or generated dynamically in code-behind, use the **`Document`** property (which accepts an `XmlDocument` object) or the **`DocumentContent`** property (which accepts a raw XML string) instead of `DocumentSource`.
3. **Styling the Output:**
By default, raw XML loaded via `DocumentSource` might not render in a user-friendly format in the browser. To format and style the XML output into HTML, pair the `DocumentSource` property with the **`TransformSource`** property to apply an XSLT stylesheet.
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