GDAL – Convert WFS GetFeature GML to Shapefile Using ogr2ogr in QGIS Server

gdalogrogr2ogrqgis-serverwfs

I'd like to use ogr2ogr with the WFS driver to convert the GML response of my QGIS Server 3.4.2 GetFeature layer into Shapefile. I have to do this from a WebGIS JavaScript application I am developing, via (e.g.) a click event on a "Download" button.

First of all, is there a way to do this with QGIS Server itself without implementing this functionality myself (I cannot see any outputFormat for Shapefile)?

If this Scenario (let's call it Scenario 1) is not possible, I thought about two alternatives, and I'd like to ask which should be the best.

Scenario 2: using PHP exec() like explained here
Scenario 3: using the node.js ogr2ogr wrapper found in this repo

Here is the GetCapabilities of my WFS: https://www.wondermap.it/cgi-bin/qgis_mapserv.fcgi?&map=/home/ubuntu/qgis/projects/Demo_sci_WMS/demo_sci.qgs&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetCapabilities

Best Answer

Check the service with ogrinfo

ogrinfo WFS:"https://www.wondermap.it/cgi-bin/qgis_mapserv.fcgi?&map=/home/ubuntu/qgis/projects/Demo_sci_WMS/demo_sci.qgs&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetCapabilities"

Result:

...
Metadata:
  PROVIDER_NAME=Wondermap
  TITLE=Impianti sciistici Lombardia
1: domini_sciabili (Multi Polygon)
2: impianti_risalita (Multi Line String)
3: piste_sci (Multi Line String)

Find summary of one layer

ogrinfo WFS:"https://www.wondermap.it/cgi-bin/qgis_mapserv.fcgi?&map=/home/ubuntu/qgis/projects/Demo_sci_WMS/demo_sci.qgs&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetCapabilities" domini_sciabili -so

Result

Metadata:
  PROVIDER_NAME=Wondermap
  TITLE=Impianti sciistici Lombardia

Layer name: domini_sciabili
Metadata:
  TITLE=domini sciabili
Geometry: Multi Polygon
Feature Count: 38
Extent: (526875.694200, 5096641.169516) - (615063.094113, 5155811.7
Layer SRS WKT:
PROJCS["WGS 84 / UTM zone 32N",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",9],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","32632"]]
Geometry Column = geometry
gml_id: String (0.0) NOT NULL
Id: Integer (0.0)
CODICE: String (0.0)
SOSTENIBIL: String (0.0)
COMUNE: String (0.0)
DENOMINAZ: String (0.0)
FONTE: String (0.0)
STATO: String (0.0)

Get features with BBOX and save into shapefile

ogr2ogr -f "ESRI Shapefile" -spat 544138 5098446 564138 5108446 wfs_test.shp WFS:"https://www.wondermap.it/cgi-bin/qgis_mapserv.fcgi?&map=/home/ubuntu/qgis/projects/Demo_sci_WMS/demo_sci.qgs&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetCapabilities" domini_sciabili

Check what you got

ogrinfo wfs_test.shp -so

INFO: Open of `wfs_test.shp'
      using driver `ESRI Shapefile' successful.

Layer name: wfs_test
Metadata:
  DBF_DATE_LAST_UPDATE=2018-12-16
Geometry: Polygon
Feature Count: 1
Extent: (543944.462085, 5096641.169516) - (544546.601519, 5098546.684997)
Layer SRS WKT:
PROJCS["WGS 84 / UTM zone 32N",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.257223563,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.0174532925199433,
            AUTHORITY["EPSG","9122"]],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",9],
    PARAMETER["scale_factor",0.9996],
    PARAMETER["false_easting",500000],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    AXIS["Easting",EAST],
    AXIS["Northing",NORTH],
    AUTHORITY["EPSG","32632"]]
gml_id: String (80.0)
Id: Integer (9.0)
CODICE: String (80.0)
SOSTENIBIL: String (80.0)
COMUNE: String (80.0)
DENOMINAZ: String (80.0)
FONTE: String (80.0)
STATO: String (80.0)

For attribute queries use ogr2ogr with -where or -sql as documented https://www.gdal.org/ogr2ogr.html. I suggest to read also the WFS driver manual https://gdal.org/drivers/vector/wfs.html.

Related Solutions

[GIS] Get data from WFS and present in using d3js – correct projection

I would suggest Albers equal-area conic as in this example for the UK and adjust the parameters for Poland.

First generate your topojson from the GML file with the following two commands (note that the the geographic coordinates in gml are swapped, so we need to tell ogr2ogr swap them back with the --config options):

ogr2ogr -f "GeoJSON" --config GML_INVERT_AXIS_ORDER_IF_LAT_LONG YES --config GML_CONSIDER_EPSG_AS_URN YES poland.json poland.gml
topojson -o pl.json poland.json

For Poland you want to set the standard parallels to something like 48°N and 56°N, rotate longitude by -19° and set the center to 0°W 52°N.

The complete code is:

<!DOCTYPE html>
<meta charset="utf-8">
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/topojson.v1.min.js"></script>

<script>
var width = 600,
    height = 600;

var projection = d3.geo.albers()
    .center([0, 52])
    .rotate([-19, 0])
    .parallels([48, 56])
    .scale(5000)
    .translate([width / 2, height / 2]);

var path = d3.geo.path()
    .projection(projection);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

d3.json("pl.json", function(error, pl) {
  svg.append("path")
      .datum(topojson.feature(pl, pl.objects.poland))
      .attr("d", path)
      .attr("fill", "#eee");
});
</script>

enter image description here

[GIS] GeoServer & QGIS – Using GeoJSON in a WFS request

I had to deviate from the orignal plan to load my data as GeoJSON through a WFS. As @ian-turton mentioned above it makes no sense to use GeoJSOn here because GeoServer and QGIS doing a good job with GML.

So I tried the GML Application Schema toolbox QGIS plugin recommended by @user30184.

"This plugin allows then to extract each “Complex Feature” from a GML document and to store it as a row in a vector layer." - GML application schema toolbox doc

My configuration on the GeoServer:

I'm working with the App Schema tutorial data
The complex data is stored in a Java Property file which contains Feature information
The data store contains the mapping file of the complex features

Steps you have to do within the plugin:

Select the source of the data: WFS
Connect to the GeoServer
Selection of FeatureTypes you want to map
Load in XML mode

As you can see in the screenshot, my complex features are stored in three separate layer (left). The features attributes table (right) shows the complex relationships.

Best Answer

Related Solutions

[GIS] Get data from WFS and present in using d3js – correct projection

[GIS] GeoServer & QGIS – Using GeoJSON in a WFS request

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