feat: add multiple authors to a post (#677)

Resolves #675

_layouts/post.html

@@ -57,25 +57,25 @@ <h1 data-toc-skip>{{ page.title }}</h1>
   {% endif %}
 
   <div class="d-flex justify-content-between">
-    <!-- author -->
+    <!-- author(s) -->
     <span>
-      {% capture author_name %}{{ site.data.authors[page.author].name | default: site.social.name }}{% endcapture %}
-      {% assign author_link = nil %}
-
       {% if page.author %}
-        {% assign author_link = site.data.authors[page.author].url %}
-      {% elsif author_name == site.social.name %}
-        {% assign author_link = site.social.links[0] %}
+        {% assign authors = page.author %}
+      {% elsif page.authors %}
+        {% assign authors = page.authors %}
       {% endif %}
 
       {{ site.data.locales[lang].post.written_by }}
 
       <em>
-        {% if author_link %}
-          <a href="{{ author_link }}">{{ author_name }}</a>
-        {% else %}
-        {{ author_name }}
-        {% endif %}
+      {% if authors %}
+        {% for author in authors %}
+          <a href="{{ site.data.authors[author].url }}">{{ site.data.authors[author].name }}</a>
+          {% unless forloop.last %}</em>, <em>{% endunless %}
+        {% endfor %}
+      {% else %}
+        <a href="{{ site.social.links[0] }}">{{ site.social.name }}</a>
+      {% endif %}
       </em>
     </span>
 

_posts/2019-08-08-write-a-new-post.md

@@ -48,7 +48,7 @@ tags: [bee]
 
 The author information of the post usually does not need to be filled in the _Front Matter_ , they will be obtained from variables `social.name` and the first entry of `social.links` of the configuration file by default. But you can also override it as follows:
 
-Add author information in `_data/authors.yml` (If your website doesn't have this file, don't hesitate to create one.)
+Adding author information in `_data/authors.yml` (If your website doesn't have this file, don't hesitate to create one).
 
 ```yaml
 <author_id>:
@@ -58,15 +58,21 @@ Add author information in `_data/authors.yml` (If your website doesn't have this
 ```
 {: file="_data/authors.yml" }
 
-And then set up the custom author in the post's YAML block:
+
+And then use `author` to specify a single entry or `authors` to specify multiple entries:
 
 ```yaml
 ---
-author: <author_id>
+author: <author_id>                     # for single entry
+# or
+authors: [<author1_id>, <author2_id>]   # for multiple entries
 ---
 ```
 
-> Another benefit of reading the author information from the file `_data/authors.yml`{: .filepath } is that the page will have the meta tag `twitter:creator`, which enriches the [Twitter Cards](https://developer.twitter.com/en/docs/twitter-for-websites/cards/guides/getting-started#card-and-content-attribution) and is good for SEO.
+
+Having said that, the key `author` can also identify multiple entries.
+
+> The benefit of reading the author information from the file `_data/authors.yml`{: .filepath } is that the page will have the meta tag `twitter:creator`, which enriches the [Twitter Cards](https://developer.twitter.com/en/docs/twitter-for-websites/cards/guides/getting-started#card-and-content-attribution) and is good for SEO.
 {: .prompt-info }
 
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