Implement average for table totals

[PhilippGrashoff]

Currently, there is no "avg" for table totals. Implementation would be easy, I can take care of it when I update to current versions. Code is quite finished:

1. new property avgCount for table: $this->avgCount = 0;
2. that code in updateTotals:

case 'avg':
    if($this->model[$key] !== null) { //only use non null values for sensible average calculation
        $this->totals[$key] = (($this->totals[$key] * $this->avgCount) + $this->model[$key]) / ($this->avgCount + 1);
        $this->avgCount++;
    }
    break;

[DarkSide666]

Well I guess it's a bit to much calculations.
Probably better would be to use two protected (for internal use) table properties:

case 'avg':
    if($this->model[$key] !== null) { //only use non null values for sensible average calculation
        $this->avgSum += $this->model['key'];
        $this->avgCount++;
        $this->totals[$key] = $this->avgSum / $this->avgCount;
    }
    break;

[PhilippGrashoff]

definitely the more sensible approach!

[PhilippGrashoff]

aaaah, avgSum and avgCount need to be arrays, as we might calculcate an avg for more than one column :)

[DarkSide666]

Oh, yes, correct.
Can you create PR for this?

case 'avg':
    if (is_numeric($this->model[$key])) { //only use numeric values
        $this->avgSum[$key] = ($this->avgSum[$key] ?? 0) + $this->model['key'];
        $this->avgCount[$key] = ($this->avgCount[$key] ?? 0) + 1;
        $this->totals[$key] = $this->avgSum[$key] / $this->avgCount[$key];
    }
    break;

[PhilippGrashoff]

Will do when I switch to newest ATK versions, still on 1.7

[romaninsh]

Related #286

[mvorisek]

@PhilippGrashoff should be possible with extra expression column, but of course only as workaround for now

[mvorisek]

closing in favor of #286