Flatten XML

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The Flatten XML transform turns rows of data containing XML text into separate columns for each of its values. XML is a common result of using the Generic Web data provider to connect to online data sources, for example.

1. Input

The Flatten XML transform requires one column containing XML text.

There might be only one row containing all of the XML, or it could be split into multiple rows.

Input XML in multiple rows
Input XML in multiple rows

2. Add the transform

Optionally, click to select an existing connection between two of your transforms where you want to insert one.

In the toolbar, choose Insert Other, then Flatten XML.

Adding the transform
Adding the transform

If you didn't select an insertion point earlier, click and drag from the transform you want to use as input onto the new transform to connect it.

Connect the transform if needed
Connect the transform if needed

The transform initially appears red because it requires configuration.

New transform added
New transform added

3. Configure

Open the configuration dialog by clicking or right-clicking the new transform and choosing Configure in the toolbar or menu (or double-clicking the transform).

Transform configuration dialog
Transform configuration dialog

If your input has more than one column, set the Input Element dropdown to the one containing XML text.

Next, click Discover to automatically populate mappings and other details defining the structure and data types of your columns based on the current input XML. A notification will appear in the lower right corner of the screen when complete, often right away.

Discovery complete
Discovery complete

Note
Only one type of child element can be included in the output at a time per parent element. You can edit these record selector mappings as shown below to choose which one to include.

If the XML contains prefixes (e.g., <prefix:element>...), these may have been populated under the Namespaces heading along with their corresponding URLs in order to parse the XML correctly.

3.1. Editing mappings

Click Mappings to confirm or change the discovered mappings, although this is typically not required.

The initial Mappings dialog shows the top level of the discovered elements in your XML.

Click the Edit icon to configure a mapping
Click the Edit icon to configure a mapping

Tip
If no mappings were discovered, check that the Input Element dropdown was set correctly, or open the Data Preview with the preceding transform selected to confirm the input is XML that can be converted into columns.

Your top-level element might only contain child or sub-elements like the example above rather than directly containing data.

Click the Edit icon for a mapping to open its details.

A record selector mapping contains its own child mappings
A record selector mapping contains its own child mappings

The Mapping Path is set using XPath syntax to refer to an element or attribute value in the XML.

A selected Record Selector option indicates that this mapping represents multiple child elements that will each be transformed into a record.

Click on Child Mappings for this type of mapping to open another Mappings dialog like the first one above, this time for the child element.

Editing mappings containing data
Editing mappings containing data

Mappings representing data that will be turned into columns will have a type listed in the Data Type column. You can edit these mappings if you want to change the data type to something else that will be compatible with that property's values.

A mapping with [Record Selector] as its column name indicates there can be multiple child elements of that type within each of the current parent element type, so the child elements will be turned into multiple records (rows of data) and then combined/joined with the parent record. Only one of these can be enabled at each level of mappings at a time to prevent excessive duplication of the parent record's values.

You can exclude a mapping from the transform output by unchecking its checkbox along the left, or delete it using the icon along the right.

4. Output

After submitting the configuration dialogs, you can preview the output by opening the Data Preview window with the transform selected.

Output
Output

You can configure other standard transform options such as parameters and output elements by configuring the transform again.

5. See also

Dundas Data Visualization, Inc.
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Toronto, ON, Canada
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International: 1.416.467.5100

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