Load content scripts on document.body is ready

2 files changed, 49 insertions, 12 deletions

diff --git a/src/content/Bootstrap.ts b/src/content/Bootstrap.ts
new file mode 100644
index 0000000..62e1530
--- /dev/null
+++ b/src/content/Bootstrap.ts
@@ -0,0 +1,27 @@
+type Callback = () => void;
+
+export default class Bootstrap {
+  constructor() {}
+
+  isReady(): boolean {
+    return document.body !== null;
+  }
+
+  waitForReady(callback: Callback): void {
+    const observer = new MutationObserver(() => {
+      if (document.body != null) {
+        observer.disconnect();
+        callback();
+      }
+    });
+
+    observer.observe(document, {
+      attributes: false,
+      attributeOldValue: false,
+      characterData: false,
+      characterDataOldValue: false,
+      childList: true,
+      subtree: true,
+    });
+  }
+}
diff --git a/src/content/index.ts b/src/content/index.ts
index b575e0d..5252338 100644
--- a/src/content/index.ts
+++ b/src/content/index.ts
@@ -1,22 +1,32 @@
 import "reflect-metadata";
 
 import Application from "./Application";
+import Bootstrap from "./Bootstrap";
 import consoleFrameStyle from "./site-style";
 import { ConsoleFramePresenterImpl } from "./presenters/ConsoleFramePresenter";
 import { container } from "tsyringe";
 import "./di";
 
-if (window.self === window.top) {
-  new ConsoleFramePresenterImpl().initialize();
-}
+const initDom = () => {
+  if (window.self === window.top) {
+    new ConsoleFramePresenterImpl().initialize();
+  }
 
-try {
-  const app = container.resolve(Application);
-  app.run();
-} catch (e) {
-  console.error(e);
-}
+  try {
+    const app = container.resolve(Application);
+    app.run();
+  } catch (e) {
+    console.error(e);
+  }
 
-const style = window.document.createElement("style");
-style.textContent = consoleFrameStyle;
-window.document.head.appendChild(style);
+  const style = window.document.createElement("style");
+  style.textContent = consoleFrameStyle;
+  window.document.head.appendChild(style);
+};
+
+const bootstrap = new Bootstrap();
+if (bootstrap.isReady()) {
+  initDom();
+} else {
+  bootstrap.waitForReady(() => initDom());
+}