Add function to hass for calling relative_time

[colings]

I use a template to track the "real" last changed times of some of my entities, so restarting HA doesn't make it look like something changed with them.

See: https://community.home-assistant.io/t/persistent-version-of-last-changed-for-the-ui/467163/67

With button card there's a helper function I can pass the appropriate attribute from the template entity to to get a nicely formatted time (1 minute ago, last week, etc). It would be cool if Bubble Card added hass.relative_time so I could call that. For now I just wrote my own JS function to embed every time I need it, but using HA's version would be cleaner.

[Menelao147]

@colings could you share your JS function?

[colings]

Sure, here you go. This is using the last changed helper, so you'll need to tweak it to just use the normal last changed time instead of getLastChangeTime. Also, looking at it I skipped a few '1 day' vs 'x days' cases. It was supposed to just be temporary, lol.

  function getLastChangeTime() {
    return new Date(hass.states['sensor.nominal_change_history'].attributes.changes[entity]);
  }

  function timeSinceChange() {
    const last_change = getLastChangeTime();
    const now = new Date();
    const secondsAgo = (now - last_change) / 1000;
    
    if (secondsAgo < 60) {
        return `${Math.floor(secondsAgo)} seconds ago`;
    }
    if (secondsAgo < 60*2) {
        return "1 minute ago";
    }
    if (secondsAgo < 60*60) {
        return `${Math.floor(secondsAgo / 60)} minutes ago`;
    }
    if (secondsAgo < 60*60*2) {
        return "1 hour ago";
    }
    if (secondsAgo < 60*60*24) {
        return `${Math.floor(secondsAgo / 3600)} hours ago`;
    }
    if (secondsAgo < 60*60*24*2) {
        return "1 day ago";
    }
    if (secondsAgo < 2592000) {
        return `${Math.floor(secondsAgo / 86400)} days ago`;
    }
    if (secondsAgo < 31536000) {
        return `${Math.floor(secondsAgo / 2592000)} months ago`;
    }
    return `${Math.floor(secondsAgo / 31536000)} years ago`;
  }