Responsive images (#505)

assets/css/screen.css

@@ -411,10 +411,10 @@ The knock-on effect of this is ugly browser-scroll bars at the bottom, so 80px o
 }
 
 .post-card-image {
-    width: auto;
+    width: 100%;
     height: 200px;
     background: var(--lightgrey) no-repeat center center;
-    background-size: cover;
+    object-fit: cover;
 }
 
 .post-card-content-link {
@@ -595,46 +595,48 @@ The knock-on effect of this is ugly browser-scroll bars at the bottom, so 80px o
 
 /* Special Styling for home page grid (below):
 
-The first (most recent) post in the list is styled to be bigger than the others and take over the full width of the grid to give it more emphasis. Wrapped in a media query to make sure this only happens on large viewports / desktop-ish devices.
+The first post in the list is styled to be bigger than the others and take over
+the full width of the grid to give it more emphasis. Wrapped in a media query to
+make sure this only happens on large viewports / desktop-ish devices.
 
  */
 
 @media (min-width: 795px) {
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) {
+    .post-card-large {
         flex: 1 1 100%;
         flex-direction: row;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) .post-card-image-link {
+    .post-card-large .post-card-image-link {
         position: relative;
         flex: 1 1 auto;
         border-radius: 5px 0 0 5px;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) .post-card-image {
+    .post-card-large .post-card-image {
         position: absolute;
         width: 100%;
         height: 100%;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) .post-card-content {
+    .post-card-large .post-card-content {
         flex: 0 1 357px;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) h2 {
+    .post-card-large h2 {
         font-size: 2.6rem;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) p {
+    .post-card-large p {
         font-size: 1.8rem;
         line-height: 1.55em;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) .post-card-content-link {
+    .post-card-large .post-card-content-link {
         padding: 30px 40px 0;
     }
 
-    .home-template .post-feed .post-card:nth-child(6n+1):not(.no-image) .post-card-meta {
+    .post-card-large .post-card-meta {
         padding: 0 40px 30px;
     }
 }
@@ -709,22 +711,29 @@ The first (most recent) post in the list is styled to be bigger than the others
 
 .post-full-image {
     margin: 0 -10vw -165px;
-    height: 800px;
     background: var(--lightgrey) center center;
-    background-size: cover;
     border-radius: 5px;
+    overflow: hidden;
+}
+
+.post-full-image img {
+    width: 100%;
+    height: 800px;
+    object-fit: cover;
 }
 
 @media (max-width: 1170px) {
     .post-full-image {
         margin: 0 -4vw -100px;
-        height: 600px;
         border-radius: 0;
     }
+    .post-full-image img {
+        height: 600px;
+    }
 }
 
 @media (max-width: 800px) {
-    .post-full-image {
+    .post-full-image img {
         height: 400px;
     }
 }

author.hbs

@@ -3,7 +3,9 @@
 
 {{#author}}
 {{!-- Everything inside the #author tags pulls data from the author --}}
-<header class="site-header outer {{#if cover_image}}" style="background-image: url({{cover_image}}){{else}}no-cover{{/if}}">
+
+
+{{> header background=feature_image}} {{!--Special header.hbs partial to generate the <header> tag--}}
     <div class="inner">
         {{> "site-nav"}}
         <div class="site-header-content">

error-404.hbs

@@ -20,7 +20,7 @@ It's a good idea to keep this template as minimal as possible in terms of both f
             <div class="inner">
                 <nav class="site-nav-center">
                     {{#if @blog.logo}}
-                        <a class="site-nav-logo" href="{{@blog.url}}"><img src="{{@blog.logo}}" alt="{{@blog.title}}" /></a>
+                        <a class="site-nav-logo" href="{{@blog.url}}"><img src="{{img_url @blog.logo size="xs"}}" alt="{{@blog.title}}" /></a>
                     {{else}}
                         <a class="site-nav-logo" href="{{@blog.url}}">{{@blog.title}}</a>
                     {{/if}}

error.hbs

@@ -21,7 +21,7 @@ You'll notice that we *don't* use any JavsScript, or ghost_head / ghost_foot in
             <div class="inner">
                 <nav class="site-nav-center">
                     {{#if @blog.logo}}
-                        <a class="site-nav-logo" href="{{@blog.url}}"><img src="{{@blog.logo}}" alt="{{@blog.title}}" /></a>
+                        <a class="site-nav-logo" href="{{@blog.url}}"><img src="{{img_url @blog.logo size="xs"}}" alt="{{@blog.title}}" /></a>
                     {{else}}
                         <a class="site-nav-logo" href="{{@blog.url}}">{{@blog.title}}</a>
                     {{/if}}

index.hbs

@@ -2,13 +2,12 @@
 {{!-- The tag above means: insert everything in this file
 into the {body} of the default.hbs template --}}
 
-{{!-- The big featured header, it uses blog cover image as a BG if available --}}
+{{> header background=@blog.cover_image}} {{!--Special header.hbs partial to generate the <header> tag--}}
-<header class="site-header outer {{#if @blog.cover_image}}" style="background-image: url({{@blog.cover_image}}){{else}}no-cover{{/if}}">
     <div class="inner">
         <div class="site-header-content">
             <h1 class="site-title">
                 {{#if @blog.logo}}
-                    <img class="site-logo" src="{{@blog.logo}}" alt="{{@blog.title}}" />
+                    <img class="site-logo" src="{{img_url @blog.logo size="s"}}" alt="{{@blog.title}}" />
                 {{else}}
                     {{@blog.title}}
                 {{/if}}

package.json

@@ -57,6 +57,26 @@
         "gulp-uglify": "3.0.1"
     },
     "config": {
-        "posts_per_page": 25
+        "posts_per_page": 25,
+        "image_sizes": {
+            "xxs": {
+                "width": 30
+            },
+            "xs": {
+                "width": 100
+            },
+            "s": {
+                "width": 300
+            },
+            "m": {
+                "width": 600
+            },
+            "l": {
+                "width": 1000
+            },
+            "xl": {
+                "width": 2000
+            }
+        }
     }
 }

page.hbs

@@ -22,7 +22,20 @@ into the {body} of the default.hbs template --}}
             </header>
 
             {{#if feature_image}}
-            <figure class="post-full-image" style="background-image: url({{feature_image}})">
+            <figure class="post-full-image">
+                {{!-- This is a responsive image, it loads different sizes depending on device
+                https://medium.freecodecamp.org/a-guide-to-responsive-images-with-ready-to-use-templates-c400bd65c433 --}}
+                <img
+                    srcset="{{img_url feature_image size="s"}} 300w,
+                            {{img_url feature_image size="m"}} 600w,
+                            {{img_url feature_image size="l"}} 1000w,
+                            {{img_url feature_image size="xl"}} 2000w"
+                    sizes="(max-width: 800px) 400px,
+                            (max-width: 1170px) 700px,
+                            1400px"
+                    src="{{img_url feature_image size="xl"}}"
+                    alt="{{title}}"
+                />
             </figure>
             {{/if}}
 

partials/byline-multiple.hbs

@@ -12,7 +12,7 @@
             <div class="author-card">
                 <div class="basic-info">
                     {{#if profile_image}}
-                        <img class="author-profile-image" src="{{profile_image}}" alt="{{name}}" />
+                        <img class="author-profile-image" src="{{img_url profile_image size="xs"}}" alt="{{name}}" />
                     {{else}}
                         <div class="author-profile-image">{{> "icons/avatar"}}</div>
                     {{/if}}
@@ -29,7 +29,9 @@
             </div>
 
             {{#if profile_image}}
-                <a href="{{url}}" class="moving-avatar"><img class="author-profile-image" src="{{profile_image}}" alt="{{name}}" /></a>
+                <a href="{{url}}" class="moving-avatar">
+                    <img class="author-profile-image" src="{{img_url profile_image size="xs"}}" alt="{{name}}" />
+                </a>
             {{else}}
                 <a href="{{url}}" class="moving-avatar author-profile-image">{{> "icons/avatar"}}</a>
             {{/if}}

partials/byline-single.hbs

@@ -3,7 +3,7 @@
 
 <section class="author-card">
     {{#if profile_image}}
-        <img class="author-profile-image" src="{{profile_image}}" alt="{{name}}" />
+        <img class="author-profile-image" src="{{img_url profile_image size="xs"}}" alt="{{name}}" />
     {{else}}
         <span class="avatar-wrapper">{{> "icons/avatar"}}</span>
     {{/if}}

partials/floating-header.hbs

@@ -2,7 +2,7 @@
     <div class="floating-header-logo">
         <a href="{{@blog.url}}">
             {{#if @blog.icon}}
-                <img src="{{@blog.icon}}" alt="{{@blog.title}} icon" />
+                <img src="{{img_url @blog.icon size="xxs"}}" alt="{{@blog.title}} icon" />
             {{/if}}
             <span>{{@blog.title}}</span>
         </a>

partials/header.hbs

@@ -0,0 +1,51 @@
+{{!--
+Wow what the hell is going on in here even?
+
+Ok so, several templates use this big header with a giant BG image. Nice idea, but big images
+have a heavy impact on performance, so it's a good idea to make them responsive. Because we
+can only get the image dynamically using Handlebars, and we can only set the image to properly
+be a background image using CSS, we end up with a handful of inline styles.
+
+If the template in question has a background image, then we render responsive image styles
+for it, and apply those styles to the <header> tag. Else, we just output a <header> tag
+with a `no-image` class so we can style it accordingly.
+--}}
+
+{{#if background}}
+
+<style type="text/css">
+.responsive-header-img {
+    background-image: url({{img_url background size='xl'}});
+}
+@media(max-width: 1000px) {
+.responsive-header-img {
+    background-image: url({{img_url background size='l'}});
+    background-image: -webkit-image-set(
+        url({{img_url background size='l'}}) 1x,
+        url({{img_url background size='xl'}}) 2x
+    );
+    background-image: image-set(
+        url({{img_url background size='l'}}) 1x,
+        url({{img_url background size='xl'}}) 2x
+    );
+}
+@media(max-width: 600px) {
+.responsive-header-img {
+    background-image: url({{img_url background size='m'}});
+    background-image: -webkit-image-set(
+        url({{img_url background size='m'}}) 1x,
+        url({{img_url background size='l'}}) 2x
+    );
+    background-image: image-set(
+        url({{img_url background size='m'}}) 1x,
+        url({{img_url background size='l'}}) 2x
+    );
+}
+</style>
+<header class="site-header outer responsive-header-img">
+
+{{else}}
+
+<header class="site-header outer no-image">
+
+{{/if}}

partials/post-card.hbs

@@ -1,21 +1,38 @@
-<article class="post-card {{post_class}}{{#unless feature_image}} no-image{{/unless}}">
+<article class="post-card {{post_class}} {{#unless feature_image}}no-image{{else}}{{#is "home"}}{{#has index="nth:6"}}post-card-large{{/has}}{{/is}}{{/unless}}">
+
     {{#if feature_image}}
-        <a class="post-card-image-link" href="{{url}}">
+    <a class="post-card-image-link" href="{{url}}">
-            <div class="post-card-image" style="background-image: url({{feature_image}})"></div>
+        {{!-- This is a responsive image, it loads different sizes depending on device
-        </a>
+        https://medium.freecodecamp.org/a-guide-to-responsive-images-with-ready-to-use-templates-c400bd65c433 --}}
+        <img class="post-card-image"
+            srcset="{{img_url feature_image size="s"}} 300w,
+                    {{img_url feature_image size="m"}} 600w,
+                    {{img_url feature_image size="l"}} 1000w,
+                    {{img_url feature_image size="xl"}} 2000w"
+            sizes="(max-width: 1000px) 400px, 700px"
+            src="{{img_url feature_image size="m"}}"
+            alt="{{title}}"
+        />
+    </a>
     {{/if}}
+
     <div class="post-card-content">
+
         <a class="post-card-content-link" href="{{url}}">
+
             <header class="post-card-header">
                 {{#if primary_tag}}
                     <span class="post-card-tags">{{primary_tag.name}}</span>
                 {{/if}}
                 <h2 class="post-card-title">{{title}}</h2>
             </header>
+
             <section class="post-card-excerpt">
                 <p>{{excerpt words="33"}}</p>
             </section>
+
         </a>
+
         <footer class="post-card-meta">
 
             <ul class="author-list">
@@ -27,7 +44,9 @@
                     </div>
 
                     {{#if profile_image}}
-                        <a href="{{url}}" class="static-avatar"><img class="author-profile-image" src="{{profile_image}}" alt="{{name}}" /></a>
+                        <a href="{{url}}" class="static-avatar">
+                            <img class="author-profile-image" src="{{img_url profile_image size="xs"}}" alt="{{name}}" />
+                        </a>
                     {{else}}
                         <a href="{{url}}" class="static-avatar author-profile-image">{{> "icons/avatar"}}</a>
                     {{/if}}
@@ -38,5 +57,7 @@
             <span class="reading-time">{{reading_time}}</span>
 
         </footer>
-    </div>
+
+    </div>{{!--/.post-card-content--}}
+
 </article>

post.hbs

@@ -28,7 +28,20 @@ into the {body} of the default.hbs template --}}
             </header>
 
             {{#if feature_image}}
-            <figure class="post-full-image" style="background-image: url({{feature_image}})">
+            <figure class="post-full-image">
+                {{!-- This is a responsive image, it loads different sizes depending on device
+                https://medium.freecodecamp.org/a-guide-to-responsive-images-with-ready-to-use-templates-c400bd65c433 --}}
+                <img
+                    srcset="{{img_url feature_image size="s"}} 300w,
+                            {{img_url feature_image size="m"}} 600w,
+                            {{img_url feature_image size="l"}} 1000w,
+                            {{img_url feature_image size="xl"}} 2000w"
+                    sizes="(max-width: 800px) 400px,
+                            (max-width: 1170px) 700px,
+                            1400px"
+                    src="{{img_url feature_image size="xl"}}"
+                    alt="{{title}}"
+                />
             </figure>
             {{/if}}
 
@@ -82,10 +95,10 @@ into the {body} of the default.hbs template --}}
                 {{#if related_posts}}
                 <article class="read-next-card"
                     {{#if ../primary_tag.feature_image}}
-                        style="background-image: url({{../primary_tag.feature_image}})"
+                        style="background-image: url({{img_url ../primary_tag.feature_image size="m"}})"
                     {{else}}
                         {{#if @blog.cover_image}}
-                            style="background-image: url({{@blog.cover_image}})"{{/if}}
+                            style="background-image: url({{img_url @blog.cover_image size="m"}})"{{/if}}
                     {{/if}}
                 >
                     <header class="read-next-card-header">

tag.hbs

@@ -1,9 +1,8 @@
 {{!< default}}
 {{!-- The tag above means - insert everything in this file into the {body} of the default.hbs template --}}
 
-{{!-- The big featured header, it uses blog cover image as a BG if available --}}
 {{#tag}}
-<header class="site-header outer {{#if feature_image}}" style="background-image: url({{feature_image}}){{else}}no-cover{{/if}}">
+{{> header background=feature_image}} {{!--Special header.hbs partial to generate the <header> tag--}}
     <div class="inner">
         {{> "site-nav"}}
         <div class="site-header-content">