QWC Print service¶

Forwards a print request to the OGC service, allowing injecting additional GetPrint WMS parameters (i.e. layout user labels).

API documentation:

http://localhost:5019/api/

Configuration¶

The static config files are stored as JSON files in $CONFIG_PATH with subdirectories for each tenant, e.g. $CONFIG_PATH/default/*.json. The default tenant name is default.

JSON config¶

• JSON schema
• File location: $CONFIG_PATH/<tenant>/printConfig.json

Example:

{
  "$schema": "https://raw.githubusercontent.com/qwc-services/qwc-print-service/master/schemas/qwc-print-service.json",
  "service": "print",
  "config": {
    "ogc_service_url": "http://localhost:5013/ows/",
    "print_pdf_filename": "qwc.pdf",
    "label_queries": [
      {
        "db_url": "postgresql:///?service=fachdaten",
        "query": "SELECT 'Bearbeiter/in: ' ||  vorname || ' ' || nachname FROM benutzer WHERE username = $username$",
        "params": [
          "NAME"
        ]
      }
    ],
    "label_values": [
      {
        "field": "USERNAME",
        "value": "$username$"
      }
    ]
  }
}

label_queries allows configuring additional parameters to inject into the WMS GetPrint request, which will be computed from a DB query The format is as follows:

"label_queries": [
  {
    "db_url": "<db_url>",
    "query": "<query>",
    "params": ["<ParamName1>", ...]
  },{
    ...
  }
]

where:

• query is an arbitrary query, returning exactly one row. The $username$ placeholder can be used to inject the current username.
• params is an array of parameter names to inject. The same number of parameters as number of returned values by the query must be specified.

Similarly, label_values allows configuring additional static parameters to inject into the WMS GetPrint request. The format is as follows:

"label_values": [
  {
    "field": "<ParamName1>",
    "value": "<value>"
  },{
    ...
  }
]

Environment variables¶

Config options in the config file can be overridden by equivalent uppercase environment variables.

Variable	Description
OGC_SERVICE_URL	OGC Service URL
QGIS_SERVER_VERSION	QGIS Server version (e.g. 2.18.19, 3.4.1)

Docker usage¶

See sample docker-compose.yml of qwc-docker.

Development¶

Set the CONFIG_PATH environment variable to the path containing the service config and permission files when starting this service (default: config).

export CONFIG_PATH=../qwc-docker/volumes/config

Configure environment:

echo FLASK_ENV=development >.flaskenv

Install dependencies and run service:

uv run src/server.py