How-to add Select to a layer
============================

Select operations are only supported on ``vector``, ``geojson``,
``ags-vector``, ``wfs``, and ``mapserver-wfs`` map-source types.

You can also add select operations to ``ags``, ``wms``, and  ``mapserver`` mapsources using the query-as technique.

Add a supported vector map-source
---------------------------------

This how-to references the ``firestations`` source and ``fire_stations``
layer. For more information on setting those up in your local demo, read
the:doc:`./add-a-layer` guide. This example
creates a WFS-source for the Firestations layer.

Add the following to ``mapbook.xml``:

.. raw:: html

   <!-- {% raw %} -->

.. code:: xml

    <map-source name="firestations-wfs" type="mapserver-wfs">
        <file>./demo/firestations/firestations.map</file>
        <param name="typename" value="ms:fire_stations" />
        <layer name="fire_stations" selectable="true" title="Firestations">
            <template name="select"><![CDATA[
            <div class="result-item">
                <div class="result-title">
                Firestation
                </div>
                <b>Station City:</b> {{ properties.Dak_GIS__4 }}<br>
                <b>Station Number:</b> {{ properties.Dak_GIS__5 }}<br>
            <div>
            ]]></template>
        </layer>
    </map-source>

.. raw:: html

   <!-- {% endraw %} -->

The important bits
------------------

The above defines the entire map-source but the following is what
enables the layer to be used for select:

1. In ``<map-source ...>``, ``type="mapserver-wfs"``: WFS is the OGC Web
   Feature Service.

WFS servers emit actual vector features definitions and not rendered
maps.

You must have a ``<param name="typename" ...>`` in the
``<map-source ...>`` for the wfs to be valid

2. In ``<layer ...>``, ``selectable="true"``: This tells GeoMoose the
   layer can be used for selections.

3. Inside of ``<layer...>`` there is a ``<template name="select">``:
   This will be the template used by GeoMoose to render features that
   have been selected. If the template is not present then the layer
   will not make itself available to select.