fix: reading time was incorrect for cjk words (#20)

The liquid filter `number_of_words` is for english words, so here
we use a calculation to estimate accurately the words, especially
when the language is not English.

3 files changed, 24 insertions, 2 deletions

diff --git a/_includes/functions/get_reading_time.html b/_includes/functions/get_reading_time.html
index 7747108..e1d23fe 100644
--- a/_includes/functions/get_reading_time.html
+++ b/_includes/functions/get_reading_time.html
@@ -2,14 +2,34 @@
   {% assign article = include.params.article %}
 {% endif %}
 
+{% if include.params.lang %}
+  {% assign lang = include.params.lang %}
+{% else %}
+  {% assign lang = lang | default: site.lang | default: "en" %}
+{% endif %}
+
 {% if include.params.speed %}
   {% assign speed = include.params.speed %}
 {% else %}
   {% assign speed = 160 %}
 {% endif %}
 
-{% assign total_mins = article
-  | number_of_words
+{% assign words = article | number_of_words %}
+
+{% if lang != "en" %}
+  {% assign words = words
+    | times: 0.6
+    | round %}
+  {% assign words = article
+    | strip_html
+    | strip_newlines
+    | size
+    | times: 0.4
+    | plus: words
+    | round %}
+{% endif %}
+
+{% assign total_mins = words
   | divided_by: speed
   | at_least: 1 %}
 
diff --git a/_includes/views/pagination.html b/_includes/views/pagination.html
index bcc3620..c1814e3 100644
--- a/_includes/views/pagination.html
+++ b/_includes/views/pagination.html
@@ -13,6 +13,7 @@
       {%- assign date_format = site.yat.date_format | default: "%b %-d, %Y" -%}
 
       {% assign article = post.content %}
+      {% assign lang = post.lang %}
       {%- include functions.html func='get_reading_time' -%}
       {% assign reading_time = return %}
 
diff --git a/_includes/views/post-header.html b/_includes/views/post-header.html
index df6447b..e59fd91 100644
--- a/_includes/views/post-header.html
+++ b/_includes/views/post-header.html
@@ -9,6 +9,7 @@
     </time>
 
     {% assign article = page.content %}
+    {% assign lang = page.lang %}
     {%- include functions.html func='get_reading_time' -%}
     {% assign reading_time = return %}
     <span class="post-reading-time left-vsplit"><i class="fa fa-clock-o"></i> {{ reading_time }}</span>