Various Mermaid improvments

- Render into iframe for improved security - Use built-in dark theme instead of color inversion - Remove flexbox attributes, resulting in more consistent size rendering - Update API usage and update to latest version
go-gitea · Feb 15, 2022 · f501325 · f501325
1 parent 609c916
commit f501325
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Showing 8 changed files with 44 additions and 39 deletions.
diff --git a/package-lock.json b/package-lock.json
diff --git a/package.json b/package.json
@@ -23,7 +23,7 @@
     "less": "4.1.2",
     "less-loader": "10.2.0",
     "license-checker-webpack-plugin": "0.2.1",
-    "mermaid": "8.13.10",
+    "mermaid": "8.14.0",
     "mini-css-extract-plugin": "2.5.3",
     "monaco-editor": "0.32.1",
     "monaco-editor-webpack-plugin": "7.0.1",

diff --git a/web_src/js/markup/mermaid.js b/web_src/js/markup/mermaid.js
@@ -1,3 +1,4 @@
+import {isDarkTheme} from '../utils.js';
 const {mermaidMaxSourceCharacters} = window.config;
 
 function displayError(el, err) {
@@ -15,14 +16,8 @@ export async function renderMermaid() {
   const {default: mermaid} = await import(/* webpackChunkName: "mermaid" */'mermaid');
 
   mermaid.initialize({
-    mermaid: {
-      startOnLoad: false,
-    },
-    flowchart: {
-      useMaxWidth: true,
-      htmlLabels: false,
-    },
-    theme: 'neutral',
+    startOnLoad: false,
+    theme: isDarkTheme() ? 'dark' : 'neutral',
     securityLevel: 'strict',
   });
 
@@ -48,7 +43,21 @@ export async function renderMermaid() {
       mermaid.init(undefined, el, (id) => {
         const svg = document.getElementById(id);
         svg.classList.add('mermaid-chart');
-        svg.closest('pre').replaceWith(svg);
+        const iframe = document.createElement('iframe');
+        iframe.classList.add('markup-render');
+        // allow-same-origin is to set inline style below
+        iframe.sandbox = 'allow-scripts allow-same-origin';
+        iframe.srcdoc = svg.outerHTML;
+        iframe.addEventListener('load', () => {
+          const style = document.createElement('style');
+          style.appendChild(document.createTextNode(`
+            body {margin: 0; padding: 0; overflow: hidden}
+            .mermaid-chart {display: block; margin: 0 auto}
+          `));
+          iframe.contentWindow.document.head.appendChild(style);
+          iframe.style.height = `${iframe.contentWindow.document.body.scrollHeight}px`;
+        });
+        svg.closest('pre').replaceWith(iframe);
       });
     } catch (err) {
       displayError(el, err);

diff --git a/web_src/less/_base.less b/web_src/less/_base.less
@@ -6,6 +6,7 @@
   /* other variables */
   --border-radius: .28571429rem;
   --opacity-disabled: .55;
+  --height-loading: 12rem;
   --color-primary: #4183c4;
   --color-primary-dark-1: #3876b3;
   --color-primary-dark-2: #31699f;

diff --git a/web_src/less/animations.less b/web_src/less/animations.less
@@ -30,7 +30,7 @@
 
 .markup pre.is-loading,
 .editor-loading.is-loading {
-  height: 12rem;
+  height: var(--height-loading);
 }
 
 @keyframes fadein {

diff --git a/web_src/less/markup/content.less b/web_src/less/markup/content.less
@@ -536,6 +536,14 @@
   }
 }
 
+.markup-render {
+  display: block;
+  border: none;
+  width: 100%;
+  height: var(--height-loading); // actual height is set in JS after loading
+  overflow: hidden;
+}
+
 .markup-block-error {
   margin-bottom: 0 !important;
   border-bottom-left-radius: 0 !important;

diff --git a/web_src/less/markup/mermaid.less b/web_src/less/markup/mermaid.less
@@ -1,12 +1,3 @@
-.mermaid-chart {
-  display: flex;
-  justify-content: center;
-  align-items: center;
-  padding: 1rem;
-  margin: 1rem auto;
-  height: auto;
-}
-
 /* mermaid's errorRenderer seems to unavoidably spew stuff into <body>, hide it */
 body > div[id*="mermaid-"] {
   display: none !important;

diff --git a/web_src/less/themes/theme-arc-green.less b/web_src/less/themes/theme-arc-green.less
@@ -455,10 +455,6 @@ img[src$="/img/matrix.svg"] {
   filter: invert(80%);
 }
 
-.mermaid-chart {
-  filter: invert(84%) hue-rotate(180deg);
-}
-
 .is-loading::after {
   border-color: #4a4c58 #4a4c58 #d7d7da #d7d7da;
 }