validate settings + use 'date' by default + mention default in comments

config.toml

@@ -147,10 +147,10 @@ show_reading_time = true
 show_date = true
 
 # Determines how dates are displayed in the post listing (e.g. front page or /blog). Options:
-# "date" - Show only the original date of the post.
+# "date" - Show only the original date of the post (default if unset).
 # "updated" - Show only the last updated date of the post.
 # "both" - Show both the original date and the last updated date.
-post_listing_date = "both"
+post_listing_date = "date"
 
 # DEPRECATED!
 # Use Zola's built-in `bottom_footnotes = true` in the [markdown] section instead. (Available since v0.19.0)

templates/macros/list_posts.html

@@ -14,8 +14,14 @@
             {% endif %}
 
             <ul class="bloglist-meta">
-                {%- set show_date = post.date and config.extra.post_listing_date == "date" or post.date and config.extra.post_listing_date == "both" -%}
-                {%- set show_updated = post.updated and config.extra.post_listing_date == "updated" or post.updated and config.extra.post_listing_date == "both" -%}
+                {%- set allowed_post_listing_dates = ["date", "updated", "both"] -%}
+                {%- set post_listing_date = config.extra.post_listing_date | default(value="date") -%}
+                {%- if post_listing_date not in allowed_post_listing_dates -%}
+                    {{ throw(message="ERROR: Invalid value for config.extra.post_listing_date. Allowed values are 'date', 'updated', or 'both'.") }}
+                {%- endif -%}
+
+                {%- set show_date = post.date and post_listing_date == "date" or post.date and post_listing_date == "both" -%}
+                {%- set show_updated = post.updated and post_listing_date == "updated" or post.updated and post_listing_date == "both" -%}
 
                 {%- if show_date or show_updated -%}
                     {%- if show_date -%}

theme.toml

@@ -104,7 +104,7 @@ show_reading_time = true
 show_date = true
 
 # Determines how dates are displayed in the post listing (e.g. front page or /blog). Options:
-# "date" - Show only the original date of the post.
+# "date" - Show only the original date of the post (default if unset).
 # "updated" - Show only the last updated date of the post.
 # "both" - Show both the original date and the last updated date.
 post_listing_date = "date"