bobatheme/layouts/partials/twitter_cards.html

{{ $images := $.Resources.ByType "image" }}
{{ $featured := $images.GetMatch "*feature*" }}
{{ if not $featured }}
    {{ $featured = $images.GetMatch "{*cover*,*thumbnail*}" }}
{{ end }}

{{ with $featured }}
    {{ $ratio := 0 }}
    {{ if gt .Width .Height }}
        {{ $ratio = div (float .Width) .Height }}
    {{ else }}
        {{ $ratio = div (float .Height) .Width }}
    {{ end }}

    {{ if lt $ratio 1.75 }}
        <meta name="twitter:card" content="summary_large_image">
    {{ else }}
        <meta name="twitter:card" content="summary">
    {{ end }}

    <meta name="twitter:image" content="{{ $featured.Permalink }}">
{{ end }}

<meta name="twitter:title" content="{{ .Title | plainify }}">
<meta name="twitter:description" content="{{ with .Description }}{{ . }}{{ else }}{{ if .IsPage }}{{ .Summary | plainify }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}{{ end }}">

{{ with .Site.Social.twitter }}
    <meta name="twitter:site" content="@{{ . }}">
{{ end }}