Advanced Usage 🚀

For users who want to push the boundaries of their Home Assistant dashboard, ha-db_infoscreen provides several advanced features.

🛠️ Templating & Logic

The sensor stores its main payload in the departures attribute as a JSON list. This makes it incredibly easy to use Jinja2 templates for custom notifications or cards.

Example: Delay Notification

Trigger an automation only if the next train toward "Mainz" is delayed by more than 10 minutes.

{% raw %}

automation:
  - alias: "Commuter Delay Alert"
    trigger:
      - platform: template
        value_template: >
          {% set trains = state_attr('sensor.my_station', 'departures') %}
          {% if trains %}
            {{ (trains | selectattr('destination', 'search', 'Mainz') | first).delayDeparture | int > 10 }}
          {% else %}
            false
          {% endif %}
    action:
      - service: notify.mobile_app
        data:
          title: "🚆 Train Delay!"
          message: "The next train to Mainz is delayed by {{ (state_attr('sensor.my_station', 'departures') | selectattr('destination', 'search', 'Mainz') | first).delayDeparture }} minutes."

🔍 Attribute Reference

The departures list contains rich data objects. Here are the keys available for advanced templating:

Example: Wagon Sector & Occupancy

- type: markdown
  content: >
    {% set trains = state_attr('sensor.frankfurt_hbf', 'departures') %}
    {% if trains %}
      {% set t = trains[0] %}
      **Next Train**: {{ t.train }}
      **Platform**: {{ t.platform }} (Sectors: {{ t.platform_sectors }})
      **Occupancy**:
      {% if t.occupancy == 1 %} 🟢 (Low)
      {% elif t.occupancy == 2 %} 🟡 (Medium)
      {% elif t.occupancy == 3 %} 🟠 (High)
      {% elif t.occupancy == 4 %} 🔴 (Full)
      {% else %} ⚪ (Unknown)
      {% endif %}
    {% else %}
      No departures available.
    {% endif %}

📡 Self-Hosting the Backend

If you have a high number of sensors or want maximum privacy, you can host your own instance of the db-fakedisplay API.

Docker Compose Example

services:
  dbf:
    image: derf/db-fakedisplay:latest
    ports:
      - "8080:8080"
    restart: always

Once running, update the Custom API URL in the integration settings to: http://<your-ip>:8080

🤖 Automated API Tracking

A unique feature of this project is its tight integration with the upstream backend. - The Version File: We maintain a .backend_version file in our repository. - Renovate: Our CI system (Renovate) monitors the derf/db-fakedisplay project for releases. - Automatic Verification: When a new version is released, Renovate creates a PR to update our tracked version. This triggers our GitHub Actions to run the full suite of stability tests against the new backend logic before you even receive an update. - Reliability: This ensures that ha-db_infoscreen remains compatible with backend changes without manual intervention.