.. -*- rst -*-

.. highlightlang:: none

.. groonga-command
.. database: functions_html_untag

html_untag
==========

Summary
-------

``html_untag`` strips HTML tags from HTML and outputs plain text.

``html_untag`` is used in ``--output_columns`` described at :doc:`/reference/commands/select`.

Syntax
------

``html_untag`` requires only one argument. It is ``column``.

::

  html_untag(column)


Usage
-----

Here are a schema definition and sample data to show usage.

Sample schema:

.. groonga-command
.. include:: ../../example/reference/functions/html_untag/usage_setup_schema.log
.. table_create WebClips TABLE_NO_KEY
.. column_create WebClips url COLUMN_SCALAR ShortText
.. column_create WebClips content COLUMN_SCALAR ShortText
.. column_create WebClips tag COLUMN_VECTOR ShortText

Sample data:

.. groonga-command
.. include:: ../../example/reference/functions/html_untag/usage_setup_data.log
.. load --table WebClips
.. [
.. {"_key": 1, "url": "http://groonga.org", "tag": ["groonga"], "content": "groonga is <span class='emphasize'>fast</span>"},
.. {"_key": 2, "url": "http://mroonga.org", "tag": ["mroonga"], "content": "mroonga is <span class=\"emphasize\">fast</span>"},
.. ]

Here is the simple usage of ``html_untag`` function which strips HTML tags from content of column.

.. groonga-command
.. include:: ../../example/reference/functions/html_untag/usage_html_untag.log
.. select WebClips --output_columns "_key, html_untag(content)" --command_version 2

When executing the above query, you can see "span" tag with "class" attribute is stripped.
Note that you must specify ``--command_version 2`` to use ``html_untag`` function.

Parameters
----------

There is one required parameter, ``column``.

``column``
^^^^^^^^^^

It specifies a column of the table.

Return value
------------

``html_untag`` returns plain text which is stripped HTML tags from content of column.