2013-09-08 20:42:39 +02:00
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============================
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Previews for Spatial Formats
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============================
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The extension includes some plugins that implement the IResourcePreview_
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interface, allowing to preview spatial resource files. They are based in
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popular Javascript mapping libraries and should be really easy to extend and
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adapt to your own needs.
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GeoJSON Preview
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---------------
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.. image:: _static/preview-geojson.png
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The GeoJSON previewer is based on Leaflet_. It will render GeoJSON_ files on a
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map and add a popup showing the features properties, for those resources that
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2013-11-07 19:05:44 +01:00
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have a format of ``geojson`` or ``gjson``.
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2013-09-08 20:42:39 +02:00
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To enable the GeoJSON previewer you need to add the ``geojson_preview`` plugin
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to your ini file. This plugin also requires the `resource_proxy`_
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plugin (Make sure you load the ``resource_proxy`` plugin before any other
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from the spatial extension)::
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ckan.plugins = resource_proxy geojson_preview
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WMS Preview
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-----------
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.. image:: _static/preview-wms.png
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The WMS previewer is based o OpenLayers_. When the plugin is enabled, if
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datasets contain a resource that has ``wms`` format, the resource page will
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load a simple map viewer that will attempt to load the remote service layers,
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based on the GetCapabilities response.
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To enable the WMS previewer you need to add the ``wms_preview`` plugin to your
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ini file. This plugin also requires the `resource_proxy`_
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plugin (Make sure you load the ``resource_proxy`` plugin before any other
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from the spatial extension::
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ckan.plugins = resource_proxy wms_preview
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.. note:: Please note that the WMS previewer included in ckanext-spatial is
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just a proof of concept and has important limitations, and is
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just intended as a bootstrap for developers willing to build a more
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sophisticated one.
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Some projects that have built more advanced map viewers and
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integrated them with CKAN include:
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* Data.gov.uk (http://data.gov.uk):
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- https://github.com/datagovuk/ckanext-dgu
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- https://github.com/datagovuk/ckanext-os
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* Catalog.data.gov (http://catalog.data.gov):
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- https://github.com/okfn/ckanext-geodatagov
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- https://github.com/chilukey/viewer
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.. _IResourcePreview: http://docs.ckan.org/en/latest/writing-extensions.html#ckan.plugins.interfaces.IResourcePreview
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.. _resource_proxy: http://docs.ckan.org/en/latest/data-viewer.html#viewing-remote-resources-the-resource-proxy
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.. _Leaflet: http://leafletjs.org
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.. _GeoJSON: http://geojson.org
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.. _OpenLayers: http://openlayers.org
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