QWC Print service¶

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

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.

Run locally¶

Install dependencies and run:

export CONFIG_PATH=<CONFIG_PATH>
uv run src/server.py

To use configs from a qwc-docker setup, set CONFIG_PATH=<...>/qwc-docker/volumes/config.

Set FLASK_DEBUG=1 for additional debug output.

Set FLASK_RUN_PORT=<port> to change the default port (default: 5000).

API documentation:

http://localhost:$FLASK_RUN_PORT/api/

Docker usage¶

The Docker image is published on Dockerhub.

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