Operation: Render Markdown

package.json

@@ -126,6 +126,7 @@
     "lodash": "^4.17.15",
     "loglevel": "^1.6.3",
     "loglevel-message-prefix": "^3.0.0",
+    "markdown-it": "^9.0.0",
     "moment": "^2.24.0",
     "moment-timezone": "^0.5.25",
     "ngeohash": "^0.6.3",

src/core/operations/RenderMarkdown.mjs

@@ -0,0 +1,69 @@
+/**
+ * @author j433866 [j433866@gmail.com]
+ * @copyright Crown Copyright 2019
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation.mjs";
+import MarkdownIt from "markdown-it";
+import hljs from "highlight.js";
+
+/**
+ * Render Markdown operation
+ */
+class RenderMarkdown extends Operation {
+
+    /**
+     * RenderMarkdown constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Render Markdown";
+        this.module = "Default";
+        this.description = "Renders input Markdown as HTML.";
+        this.infoURL = "https://wikipedia.org/wiki/Markdown";
+        this.inputType = "string";
+        this.outputType = "html";
+        this.args = [
+            {
+                name: "Autoconvert URLs to links",
+                type: "boolean",
+                value: false
+            },
+            {
+                name: "Enable syntax highlighting",
+                type: "boolean",
+                value: true
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {html}
+     */
+    run(input, args) {
+        const [convertLinks, enableHighlighting] = args,
+            md = new MarkdownIt({
+                linkify: convertLinks,
+                html: false, // Explicitly disable HTML rendering
+                highlight: function(str, lang) {
+                    if (lang && hljs.getLanguage(lang) && enableHighlighting) {
+                        try {
+                            return hljs.highlight(lang, str).value;
+                        } catch (__) {}
+                    }
+
+                    return "";
+                }
+            }),
+            rendered = md.render(input);
+
+        return `<div style="font-family: var(--primary-font-family)">${rendered}</div>`;
+    }
+
+}
+
+export default RenderMarkdown;