Detect embedded and skip addons (#415)

Check if addons library is being loaded inside an iframe, and skip
loading it.

Closes #412

src/index.js

@@ -9,8 +9,10 @@ import * as hotkeys from "./hotkeys";
 import * as linkpreviews from "./linkpreviews";
 import * as filetreediff from "./filetreediff";
 import * as customscript from "./customscript";
+import { default as objectPath } from "object-path";
 import {
   domReady,
+  isEmbedded,
   IS_PRODUCTION,
   setupLogging,
   getMetadataValue,
@@ -46,6 +48,15 @@ export function setup() {
         return getReadTheDocsConfig(sendUrlParam);
       })
       .then((config) => {
+        const loadWhenEmbedded = objectPath.get(
+          config,
+          "addons.options.load_when_embedded",
+          false,
+        );
+        if (isEmbedded() && !loadWhenEmbedded) {
+          return false;
+        }
+
         const httpStatus = getMetadataValue("readthedocs-http-status");
         let promises = [];
 

src/utils.js

@@ -37,6 +37,16 @@ export const domReady = new Promise((resolve) => {
   }
 });
 
+/**
+ * Check if addons are running inside iframe.
+ *
+ * The simplest way to check that is comparing the current windown with the parent window.
+ * If they are different, it means we are embedded.
+ */
+export function isEmbedded() {
+  return window.self !== window.parent;
+}
+
 /**
  * Addon base class
  *