.. _functx_id-from-element:

======================
functx:id-from-element
====================== 

Gets the ID of an XML element

Description
~~~~~~~~~~~
The functx:id-from-element function takes the $element element and returns its 
attribute (there can only be one) that is of type xs:ID. If no such attribute 
exists, or if the argument is the empty sequence, the function returns the empty 
sequence. The attribute must have been declared to be of type xs:ID in a schema, 
and validated by that schema, for this function to return it.

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   :header-rows: 1

   * - **Parameters**
     - **Description**
   * - element:element()
     - the element

Examples
~~~~~~~~
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   :header-rows: 1

   * - **XPath**
     - **Results**
     - **Explanation**
   * - functx:id-from-element($book/book/section[1])
     - preface
     - Assumes that the attribute id of $element is declared to be of type xs:ID.
.. list-table::
   :widths: 50 50
   :header-rows: 1

   * - **XPath**
     - **Results**
   * - functx:id-from-element($book/book/section[1])
     - preface

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`id`.
* :ref:`idref`.