Update default archetype

Update the default archetype to specify all relevant frontmatter fields.
Updated the bigimg and comments features to handle "unset" or "null"
values in the frontmatter and default appropriately. Also updated the
bigimg sample to explain both the default and "flow" YAML syntax.

archetypes/default.md

@@ -1,6 +1,6 @@
-+++
-title = ""
-subtitle = ""
-date = "2014-07-11T10:54:24+02:00"
-bigimg = ""
-+++
+---
+subtitle: ""
+comments: 
+tags: []
+bigimg: [{}]
+---

exampleSite/content/post/2017-03-07-bigimg-sample.md

@@ -17,10 +17,24 @@ bigimg: [{src: "/img/triangle.jpg", desc: "Triangle"}]
 
 Multiple bigimgs can be specified in the front matter by the following YAML:
 ```
-bigimg: [{src: "/img/triangle.jpg", desc: "Triangle"}, {src: "/img/sphere.jpg", desc: "Sphere"}, {src: "/img/hexagon.jpg", desc: "Hexagon"}]
+bigimg: [{src: "/img/triangle.jpg", desc: "Triangle"}, 
+         {src: "/img/sphere.jpg", desc: "Sphere"}, 
+         {src: "/img/hexagon.jpg", desc: "Hexagon"}]
 ```
 
 Also note that the description field is optional, and images could instead be specified by:
 ```
-bigimg: [{src: "/img/triangle.jpg"}, {src: "/img/sphere.jpg"}, {src: "/img/hexagon.jpg"}]
-```
+bigimg: [{src: "/img/triangle.jpg"}, 
+         {src: "/img/sphere.jpg"}, 
+         {src: "/img/hexagon.jpg"}]
+```
+
+The above YAML array of hashes were written in "flow" style. However when generating a new page or post with `hugo new post/mypost.md`, hugo may interpret the archetype for bigimg in the default YAML style. Defining multiple bigimg's complete with descriptions in this style would be specified by:
+```
+bigimg: 
+- {src: "/img/triangle.jpg", desc: "Triangle"}
+- {src: "/img/sphere.jpg", desc: "Sphere"}
+- {src: "/img/hexagon.jpg", desc: "Hexagon"}
+```
+
+Additional information can be found [in this YAML tutorial](https://rhnh.net/2011/01/31/yaml-tutorial/).

layouts/index.html

@@ -7,12 +7,12 @@
 
     {{ partial "nav.html" . }}
 
-    {{ if .Site.Params.bigimg }}
+    {{ if isset .Site.Params.bigimg 1 }}
       <div id="header-big-imgs" data-num-img={{len .Site.Params.bigimg}} {{range $i, $img := .Site.Params.bigimg}}data-img-src-{{add $i 1}}="{{$img.src}}" data-img-desc-{{add $i 1}}="{{$img.desc}}"{{end}}></div>
     {{ end }}
 
-    <header class="header-section {{ if .Site.Params.bigimg }}has-img{{ end }}">
-      <div class="intro-header {{ if .Site.Params.bigimg }}big-img{{ else }}no-img{{ end }}">
+    <header class="header-section {{ if isset .Site.Params.bigimg 1 }}has-img{{ end }}">
+      <div class="intro-header {{ if isset .Site.Params.bigimg 1 }}big-img{{ else }}no-img{{ end }}">
         <div class="container">
           <div class="row">
             <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">

layouts/partials/disqus.html

@@ -1,4 +1,4 @@
-{{ if (.Params.comments) | or (and (not (isset .Params "comments")) (.Site.Params.comments)) }}
+{{ if (.Params.comments) | or (and (or (not (isset .Params "comments")) (eq .Params.comments nil)) (.Site.Params.comments)) }}
   {{ if .Site.DisqusShortname }}
     <div class="comments">
       {{ template "_internal/disqus.html" . }}

layouts/partials/header_wp.html

@@ -1,11 +1,10 @@
 {{ if or .Params.bigimg .Title }}
-
-  {{ if .Params.bigimg }}
+  {{ if isset .Params.bigimg 1 }}
     <div id="header-big-imgs" data-num-img={{len .Params.bigimg}} {{range $i, $img := .Params.bigimg}}data-img-src-{{add $i 1}}="{{$img.src}}" {{ if $img.desc}}data-img-desc-{{add $i 1}}="{{$img.desc}}"{{end}}{{end}}></div>
   {{ end }}
 
-  <header class="header-section {{ if .Params.bigimg }}has-img{{ end }}">
-    <div class="intro-header {{ if .Params.bigimg }}big-img{{ else }}no-img{{ end }}">
+  <header class="header-section {{ if isset .Params.bigimg 1 }}has-img{{ end }}">
+    <div class="intro-header {{ if isset .Params.bigimg 1 }}big-img{{ else }}no-img{{ end }}">
       {{ partial "header.html" . }}
       <span class="img-desc" style="display: inline;"></span>
     </div>

layouts/partials/page.html

@@ -2,7 +2,7 @@
   <div class="row">
     <div class="col-lg-8 col-lg-offset-2 col-md-10 col-md-offset-1">
       {{ .Content }}
-      {{ if (.Params.comments) | or (and (not (isset .Params "comments")) (.Site.Params.comments)) }}
+      {{ if (.Params.comments) | or (and (or (not (isset .Params "comments")) (eq .Params.comments nil)) (.Site.Params.comments)) }}
         {{ if .Site.DisqusShortname }}
           <div class="disqus-comments">
             {{ template "_internal/disqus.html" . }}

layouts/partials/post.html

@@ -18,7 +18,7 @@
         {{ end }}
       </ul>
 
-      {{ if (.Params.comments) | or (and (not (isset .Params "comments")) (.Site.Params.comments)) }}
+      {{ if (.Params.comments) | or (and (or (not (isset .Params "comments")) (eq .Params.comments nil)) (.Site.Params.comments)) }}
         {{ if .Site.DisqusShortname }}
           <div class="disqus-comments">
             {{ template "_internal/disqus.html" . }}