Enhydris-openhigis - OpenHi layers

Overview

Enhydris-openhigis is an app that provides layers (such as water basins and river networks) for the OpenHi project. In the repository there's also MapServer configuration for serving these layers with WMS and WFS.

The app is specific to the OpenHi project and several things are hardwired in the code.

The app contains geographical models such as RiverBasinDistrict, which inherit either Gentity or Garea. So that gis people can connect to the database with a GIS client and update the contents of such tables, writeable database views (e.g. RiverBasinDistricts) are created in the openhigis database schema. Except for collecting objects from several tables (that use multi-table inheritance) into a single view, these views also use SRID=2100, transparently translating to and from 4326, which is what is actually being used for geometry storage in Gentity.

Installing and configuring

• Install Enhydris 3 or later

• Make sure enhydris_openhigis is in the PYTHONPATH, or link to it from the top-level directory of Enhydris.

• Somewhere in the Python path, create file urls.py, with contents such as this:

  from django.urls import include, path
  
  from enhydris import urls as enhydris_urls
  from enhydris_openhigis import urls as enhydris_openhigis_urls
  
  
  urlpatterns = [
      path("openhigis/", include(enhydris_openhigis_urls)),
      path("", include(enhydris_urls)),
  ]
  

• In the Enhydris enhydris_project/settings/local.py file, add enhydris_openhigis to INSTALLED_APPS, specify the urls.py file in ROOT_URLCONF, add enhydris_openhigis.middleware.OpenHiGISMiddleware to MIDDLEWARE, and specify the mapserver root url in ENHYDRIS_OWS_URL.

  ENHYDRIS_OWS_URL must end in a slash; it does not include the filename openhigis.map, which is hardwired and appended to ENHYDRIS_OWS_URL automatically. In fact, the current language may also be inserted, so that the resulting URL may be something like ENHYDRIS_OWS_URL/el/openhigis.map (but ENHYDRIS_OWS_URL/openhigis.map also works; it is the default "unlocalized"—actually English—URL).

  ENHYDRIS_OWS_URL can be empty. In that case, the openhigis UI elements (search geodata, extra layers) aren't shown. This is useful if we want the database tables/views to be installed but for the UI to be unaffected, such as when we serve many Enhydris instances from the same database and do not want all the instances to have the openhigis UI elements.

• In the Enhydris configuration directory, execute python manage.py migrate.

• Connect to PostgreSQL with ArcGIS or QGIS and add layers.

• Start MapServer and access these layers.

Meta

Copyright (C) 2018-2021 National Technical University of Athens

Copyright (C) 2018-2021 Institute of Communication and Computer Systems

Enhydris-openhigis is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License, as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.

The software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the licenses for more details.

You should have received a copy of the license along with this program. If not, see http://www.gnu.org/licenses/.

Enhydris-openhigis was funded by NTUA and ICCS as part of the OpenHi project.