Allow the webpage dashboard url to be set from an entity value or template value

The recently updated webpage dashboard is useful, but you can only provide a string as the URL. It would be much better if you could also provide an entity value or template as the URL value. Something like:

  type: iframe
  url: sensor.my_dynamic_url

This would open up the webpage dashboard to be used in a number of different ways. For me I’ve two immediate use cases:

  1. Open a URL that is based on the current date using either a template sensor, or a template value directly as the URL value to dynamically pass the date in via the querystring
  2. Use a sensor value to load different URLs at different times of the day (for example train times on the way to work in the morning, and train times on the way home in the evening)

I’m sure the community will have many more ideas, and making the URL work from an entity value / template value feels like an easy win and something Home Assistant does in a lot of other places.