From fa7d139ce5a0216ca3f6e63c78f818e9c028a3ab Mon Sep 17 00:00:00 2001
From: sean <146651411+tuta-amb@users.noreply.github.com>
Date: Tue, 16 Jan 2024 02:55:32 -0500
Subject: [PATCH] feat: External link icons (#697)

---
 quartz/plugins/transformers/links.ts | 26 +++++++++++++++++++++++++-
 quartz/styles/base.scss              | 11 +++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/quartz/plugins/transformers/links.ts b/quartz/plugins/transformers/links.ts
index 50d2d1a0..1ba0c8e5 100644
--- a/quartz/plugins/transformers/links.ts
+++ b/quartz/plugins/transformers/links.ts
@@ -21,6 +21,7 @@ interface Options {
   prettyLinks: boolean
   openLinksInNewTab: boolean
   lazyLoad: boolean
+  externalLinkIcon: boolean
 }
 
 const defaultOptions: Options = {
@@ -28,6 +29,7 @@ const defaultOptions: Options = {
   prettyLinks: true,
   openLinksInNewTab: false,
   lazyLoad: false,
+  externalLinkIcon: true,
 }
 
 export const CrawlLinks: QuartzTransformerPlugin<Partial<Options> | undefined> = (userOpts) => {
@@ -55,7 +57,29 @@ export const CrawlLinks: QuartzTransformerPlugin<Partial<Options> | undefined> =
               ) {
                 let dest = node.properties.href as RelativeURL
                 const classes = (node.properties.className ?? []) as string[]
-                classes.push(isAbsoluteUrl(dest) ? "external" : "internal")
+                const isExternal = isAbsoluteUrl(dest)
+                classes.push(isExternal ? "external" : "internal")
+
+                if (isExternal && opts.externalLinkIcon) {
+                  node.children.push({
+                    type: "element",
+                    tagName: "svg",
+                    properties: {
+                      class: "external-icon",
+                      viewBox: "0 0 512 512",
+                    },
+                    children: [
+                      {
+                        type: "element",
+                        tagName: "path",
+                        properties: {
+                          d: "M320 0H288V64h32 82.7L201.4 265.4 178.7 288 224 333.3l22.6-22.6L448 109.3V192v32h64V192 32 0H480 320zM32 32H0V64 480v32H32 456h32V480 352 320H424v32 96H64V96h96 32V32H160 32z",
+                        },
+                        children: [],
+                      },
+                    ],
+                  })
+                }
 
                 // Check if the link has alias text
                 if (
diff --git a/quartz/styles/base.scss b/quartz/styles/base.scss
index 607749aa..16a96122 100644
--- a/quartz/styles/base.scss
+++ b/quartz/styles/base.scss
@@ -59,6 +59,7 @@ a {
   text-decoration: none;
   transition: color 0.2s ease;
   color: var(--secondary);
+  display: inline-block;
 
   &:hover {
     color: var(--tertiary) !important;
@@ -76,6 +77,16 @@ a {
       padding: 0;
     }
   }
+
+  &.external .external-icon {
+    vertical-align: bottom;
+    height: 1ex;
+    margin: 0 0.15em;
+
+    > path {
+      fill: var(--dark);
+    }
+  }
 }
 
 .desktop-only {