Add time durations in frontmatter?

[Minilab]

Hello, it’s me again.

A part of the website I’m working on is a discography catalog, and among other things, I have an array of time durations for the tracks in a release in the frontmatter, e.g., [10m30s, 6m9s, 12m0s, 8m7s, 8m31s, 14m41s]

i would like to display the sum of these durations on the release’s page. How would I do this? I can’t wrap my head around Hugo and Go’s time functions, and I’m not even sure whether this is possible without using something like JS. Also, am I using the right format for the duration strings?

Thank you so much in advance!

[gaetawoo]

Without knowing about duration strings, you could range through each duration, parse it into min and sec, convert into seconds, add it as a number not string to a summation variable. Then when your done with the range, split the time back into equivalent minutes and seconds.

[Minilab]

Yes! Thanks to your suggestions I was able to do it. Thank you so much!

I’ll leave what I did here if anyone else wants to do this:

First, I formatted the frontmatter to look like this:

["00:10:30", "00:06:09", "00:12:00", "00:08:07", "00:08:31", "00:14:41"]

Then, I created a $total variable to hold the final tally in seconds.

Next, I wrote a range statement for this array, and inside it I created these variables to represent the hours, minutes, and seconds (the dot refers to the array):

{{ $times := split . ":" }}
{{ $hours := 0 }}
{{ $minutes := 0 }}
{{ $seconds := 0 }}

I then made a few if else statements to check if these values, with the leading 0s removed, are null; it outputs 0 if they are and the number without the leading 0s if they are not:

{{ if (eq (strings.TrimLeft "0" (index $times 0) ) "") }}
{{ $hours = int "0" }}
{{ else }}
{{ $hours = int (strings.TrimLeft "0" (index $times 0)) }}
{{ end }}
{{ if (eq (strings.TrimLeft "0" (index $times 1) ) "") }}
{{ $minutes = int "0" }}
{{ else }}
{{ $minutes = int (strings.TrimLeft "0" (index $times 1)) }}
{{ end }}
{{ if (eq (strings.TrimLeft "0" (index $times 2) ) "") }
{{ $seconds = int "0" }}
{{ else }}
{{ $seconds = int (strings.TrimLeft "0" (index $times 2)) }}
{{ end }}

Then, I converted the hours and minutes to seconds…

{{ $convHours := mul $hours 3600 }}
{{ $convMinutes := mul $minutes 60 }}

…added these and the seconds value together…

{{ $totalSeconds := add (add $convMinutes $convHours) $seconds }}`

…and then added this to the $total:

{{ $total = add $total $totalSeconds }}

Here, I ended the range, and I converted the $total back to individual time units, making sure to cast them as ints:

{{ $totalHours := int (math.Floor (div $total 3600)) }}
{{ $totalMinutes := int (math.Floor (div $total 60)) }}
{{ $totalSeconds := int (mod $total 60) }}

And lastly, I displayed them the way I want:

{{ printf "%02d" $totalHours }}:{{ printf "%02d" $totalMinutes }}:{{printf "%02d" $totalSeconds }}

So altogether my code looks like this:

{{ $total := 0 }}
{{ range $.Params.tracklengths }}
        {{ $times := split . ":" }}
		{{ $hours := 0 }}	
		{{ $minutes := 0 }}
		{{ $seconds := 0 }}
		{{ if (eq (strings.TrimLeft "0" (index $times 0) ) "") }}
			{{ $hours = int "0" }}
		{{ else }}
			{{ $hours = int (strings.TrimLeft "0" (index $times 0)) }}
		{{ end }}
		{{ if (eq (strings.TrimLeft "0" (index $times 1) ) "") }}
			{{ $minutes = int "0" }}
		{{ else }}
			{{ $minutes = int (strings.TrimLeft "0" (index $times 1)) }}
		{{ end }}
		{{ if (eq (strings.TrimLeft "0" (index $times 2) ) "") }}
			{{ $seconds = int "0" }}
		{{ else }}
			{{ $seconds = int (strings.TrimLeft "0" (index $times 2)) }}
		{{ end }}
		{{ $convHours := mul $hours 3600 }}
		{{ $convMinutes := mul $minutes 60 }}
		{{ $totalSeconds := add (add $convMinutes $convHours) $seconds }}
		{{ $total = add $total $totalSeconds }}
{{ end }}
{{ $totalHours := int (math.Floor (div $total 3600)) }}
{{ $totalMinutes := int (math.Floor (div $total 60)) }}
{{ $totalSeconds := int (mod $total 60) }}
<p>{{ printf "%02d" $totalHours }}:{{ printf "%02d" $totalMinutes }}:{{printf "%02d" $totalSeconds }}</p>

Again, thank you for guiding me in the right direction!

[gaetawoo]

Looks great! Well done!

[jmooring]

Front matter:

durations = ['1h1m1s', '2m2s', '3s']

Template:

{{ $startTime := time.AsTime 0 }}
{{ $endTime := time.AsTime 0 }}
{{ range .Params.durations }}
  {{ $endTime = $endTime.Add (time.ParseDuration .) }}
{{ end }}
{{ $duration := $endTime.Sub $startTime }}

{{ $duration.String }} --> 1h3m6s