1 files changed, 32 insertions, 0 deletions
diff --git a/web_src/js/utils/html.ts b/web_src/js/utils/html.ts
new file mode 100644
index 0000000000..22e5703c34
--- /dev/null
+++ b/web_src/js/utils/html.ts
@@ -0,0 +1,32 @@
+export function htmlEscape(s: string, ...args: Array<any>): string {
+  if (args.length !== 0) throw new Error('use html or htmlRaw instead of htmlEscape'); // check legacy usages
+  return s.replace(/&/g, '&amp;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#39;')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;');
+}
+
+class rawObject {
+  private readonly value: string;
+  constructor(v: string) { this.value = v }
+  toString(): string { return this.value }
+}
+
+export function html(tmpl: TemplateStringsArray, ...parts: Array<any>): string {
+  let output = tmpl[0];
+  for (let i = 0; i < parts.length; i++) {
+    const value = parts[i];
+    const valueEscaped = (value instanceof rawObject) ? value.toString() : htmlEscape(String(parts[i]));
+    output = output + valueEscaped + tmpl[i + 1];
+  }
+  return output;
+}
+
+export function htmlRaw(s: string|TemplateStringsArray, ...tmplParts: Array<any>): rawObject {
+  if (typeof s === 'string') {
+    if (tmplParts.length !== 0) throw new Error("either htmlRaw('str') or htmlRaw`tmpl`");
+    return new rawObject(s);
+  }
+  return new rawObject(html(s, ...tmplParts));
+}