From 731af8c564b2f44da1307013c0794461d561096b Mon Sep 17 00:00:00 2001
From: Alan Orth <alan.orth@gmail.com>
Date: Sat, 17 Sep 2016 18:05:22 +0300
Subject: [PATCH] layouts: Add basic support for OpenGraph and Twitter card
 metadata

Uses basic data like title, description, author, and date that we
are using with existing vanilla meta tags, but extends them to OG
and Twitter Card tags. See [0] and [1].

For the Twitter summary cards specifically, you can optionally add
attribution for your username by adding something like this to your
configuration:

  [params.social]
    twitter_username = "@mralanorth"

... and for posts with images, you can specify an "image" in the
post's front matter like so:

  image = "/2016/09/IMG_20160916_174409.jpg"

And then the theme will opt to use Twitter's "large" summary card.

[0] http://ogp.me/
[1] https://dev.twitter.com/cards/getting-started
---
 layouts/_default/baseof.html   |  7 +------
 layouts/partials/metadata.html | 36 ++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 6 deletions(-)
 create mode 100644 layouts/partials/metadata.html

diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index 44fcccf..7d70fe2 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -7,12 +7,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
     {{ "<!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->" | safeHTML }}
 
-    <meta name="description" content="{{ .Params.description | default .Site.Params.description }}">
-    <meta name="author" content="{{ .Params.author | default .Site.Params.author }}">
-
-    {{ if .Site.Params.google_verify_meta }}<meta name="google-site-verification" content="{{ .Site.Params.google_verify_meta }}">{{ end }}
-
-    {{ .Hugo.Generator }}
+    {{ partial "metadata.html" . }}
 
     <base href="{{ .Site.BaseURL }}">
     <link rel="canonical" href="{{ .Permalink }}">
diff --git a/layouts/partials/metadata.html b/layouts/partials/metadata.html
new file mode 100644
index 0000000..aed026b
--- /dev/null
+++ b/layouts/partials/metadata.html
@@ -0,0 +1,36 @@
+{{ $title := .Title | default .Site.Title }}
+{{ $description := .Params.description | default .Site.Params.description }}
+{{ $author := .Params.author | default .Site.Params.author }}
+
+    <meta name="description" content="{{ $description }}">
+    <meta name="author" content="{{ $author }}">
+
+    {{ "<!-- OpenGraph Metadata: http://ogp.me/ -->" | safeHTML }}
+    <meta property="og:title" content="{{ $title }}">
+    <meta property="og:description" content="{{ $description }}">
+
+    {{ if eq .Section "post" }}
+    <meta property="og:type" content="article">
+    <meta property="article:published_time" content="{{ .Date.Format "2006-01-02T15:04:05Z07:00" }}">
+    <meta property="article:author" content="{{ $author }}">
+      {{ if .Params.image }}
+      <meta property="og:image" content="{{ .Params.image | absURL }}">
+      {{ end }}
+    {{ else }}
+    <meta property="og:type" content="blog">
+    {{ end }}
+
+    <meta property="og:url" content="{{ .Permalink }}">
+
+    {{ "<!-- Metadata for Twitter: https://dev.twitter.com/cards/markup -->" | safeHTML }}
+    {{ if and (eq .Section "post") (.Params.image) }}
+    <meta property="twitter:card" content="summary_large_image">
+    <meta property="twitter:image" content="{{ .Params.image | absURL }}">
+    {{ else }}
+    <meta property="twitter:card" content="summary">
+    {{ end }}
+    {{ if .Site.Params.social.twitter_username}}<meta property="twitter:creator" content="{{ .Site.Params.social.twitter_username }}">{{ end }}
+    <meta property="twitter:title" content="{{ $title }}">
+    <meta property="twitter:description" content="{{ $description }}">
+
+    {{ .Hugo.Generator }}