qgis_server_render_geojson

A QGIS Server Plugin to render GEOJSON with QML styling.

With this plugin installed, your QGIS server will be able to render a geojson file to a PNG image. The geojson file can be a local file or downloaded from a network service. A qml file can be provided to define the rendering style of the geojson.

It works almost like WMS, except that the source of the data and the symbology are dynamic and must be provided as url parameter. There is also no such thing as GetCapabilities.

Quick start guide: docker-compose

git clone https://github.com/opengisch/qgis_server_render_geojson.git
cd qgis_server_render_geojson
docker-compose up

And navigate to

http://localhost:8080/ogc/?SERVICE=RenderGeojson&STYLE=polygon_outline.qml&WIDTH=300&HEIGHT=600&GEOJSON=polygon.geojson&BBOX=2689574,1283976,2689673,1284099

Quick start guide: existing qgis server infrastructure

1. Download https://github.com/opengisch/qgis_server_render_geojson/archive/master.zip
2. Unzip and copy the qgis_server_render_geojson folder to a local qgis server plugin path (check: metadata.txt must be in [plugin_path]/qgis_server_render_geojson/metadata.txt)
3. Configure the local plugin path by setting it in apache, nginx, (your favorite webserver) QGIS_PLUGINPATH=[plugin_path]
4. Restart server

Request

Parameters

The request supports the following parameters:

GEOJSON

Path to the GeoJson file. May be a URI or relative to the prefix in the configuration.

Examples

Relative to configured prefix path:

GEOJSON=naturgefahren%2Fdata.json

Absolute path (url encoded https://api.sh.ch/v1/get_geojson?topic=naturgefahren):

GEOJSON=https%3A%2F%2Fapi.sh.ch%2Fv1%2Fget_geojson%3Ftopic%3Dnaturgefahren

STYLE

Path to a qml file. May be a URI or relative to the prefix in the configuration.

The substitution variable $type is available which will be replaced with points, lines or polygons.

Examples

Static:

STYLE=naturgefahren%2Fbase.qml

Dynamic:

STYLE=naturgefahren%2F$type.qml

This will lookup up to 3 styles:

• naturgefahren/points.qml
• naturgefahren/lines.qml
• naturgefahren/polygons.qml

BBOX

The bounding box to render. Needs to match the CRS of the data in the provided GeoJSON file.

Example

BBOX=2689634.3,1283792.7,2690062.1,1284004.8

WIDTH

The width of the result image in pixels.

Example

WIDTH=640

HEIGHT

The height of the result image in pixels.

Example

HEIGHT=480

DPI

The dpi used to render the symbology.

Example

DPI=96

Examples

Basic request that will search data and style in the prefix directory (see configuration)

GET /qgis_mapserv.fcgi?SERVICE=RENDERGEOJSON&GEOJSON=data.json&STYLE=style.qml&BBOX=2689634.3,1283792.7,2690062.1,1284004.8&WIDTH=606&HEIGHT=300&DPI=96

Basic request that will search data and style in the prefix directory (see configuration)

GET /qgis_mapserv.fcgi?SERVICE=RENDERGEOJSON&GEOJSON=data.json&STYLE=$type.qml&BBOX=2689634.3,1283792.7,2690062.1,1284004.8&WIDTH=606&HEIGHT=300&DPI=96

Basic request that will create another request to collect data from another resource

GET /qgis_mapserv.fcgi?SERVICE=RENDERGEOJSON&GEOJSON=https%3A%2F%2Fapi.sh.ch%2Fv1%2Fget_geojson%3Fregion%3Dschaffhausen&STYLE=https%3A%2F%2Fapi.sh.ch%2Fstyle%3Fnaturgefahren.qml%26type%3F$type&BBOX=2689634.3,1283792.7,2690062.1,1284004.8&WIDTH=606&HEIGHT=300&DPI=96

Configuration

The prefix path where local (sytle and geojson) files are provided can be defined throug an environment variable QGIS_RENDERGEOJSON_PREFIX.