From 76e0496dfd7dade49078d05e5f0da31af404768d Mon Sep 17 00:00:00 2001
From: Amanpreet Singh <asg@fb.com>
Date: Fri, 11 Oct 2019 11:05:56 -0700
Subject: [PATCH] Default to random start position and allow URI decoding
 (#293)

* Default to random start position and allow URI decoding

* Remove unnecessary check
---
 src/esp/bindings_js/index.js                 | 11 ++++-------
 src/esp/bindings_js/modules/simenv_embind.js | 17 +++++++++++++----
 src/esp/bindings_js/modules/utils.js         | 10 ++++++++++
 src/esp/bindings_js/modules/web_demo.js      |  8 +++++++-
 src/esp/bindings_js/tests/utils.test.js      | 17 ++++++++++++++++-
 5 files changed, 50 insertions(+), 13 deletions(-)

diff --git a/src/esp/bindings_js/index.js b/src/esp/bindings_js/index.js
index 33e2257624..cf9a3eca39 100644
--- a/src/esp/bindings_js/index.js
+++ b/src/esp/bindings_js/index.js
@@ -12,7 +12,8 @@ import "./bindings.css";
 import {
   checkWebAssemblySupport,
   checkWebgl2Support,
-  getInfoSemanticUrl
+  getInfoSemanticUrl,
+  buildConfigFromURLParameters
 } from "./modules/utils";
 
 function preload(url) {
@@ -28,12 +29,7 @@ function preload(url) {
 Module.preRun.push(() => {
   let config = {};
   config.scene = defaultScene;
-  for (let arg of window.location.search.substr(1).split("&")) {
-    let [key, value] = arg.split("=");
-    if (key && value) {
-      config[key] = value;
-    }
-  }
+  buildConfigFromURLParameters(config);
   const scene = config.scene;
   Module.scene = preload(scene);
   const fileNoExtension = scene.substr(0, scene.lastIndexOf("."));
@@ -62,6 +58,7 @@ Module.onRuntimeInitialized = () => {
   if (!demo) {
     demo = new WebDemo();
   }
+
   demo.display();
 };
 
diff --git a/src/esp/bindings_js/modules/simenv_embind.js b/src/esp/bindings_js/modules/simenv_embind.js
index 72703c6c05..1f48e58a90 100644
--- a/src/esp/bindings_js/modules/simenv_embind.js
+++ b/src/esp/bindings_js/modules/simenv_embind.js
@@ -19,10 +19,14 @@ class SimEnv {
    * @param {Object} episode - episode to run
    * @param {number} agentId - default agent id
    */
-  constructor(config, episode, agentId) {
+  constructor(config, episode = {}, agentId = 0) {
     this.sim = new Module.Simulator(config);
     this.episode = episode;
-    this.initialAgentState = this.createAgentState(episode.startState);
+    this.initialAgentState = null;
+
+    if (Object.keys(episode).length > 0) {
+      this.initialAgentState = this.createAgentState(episode.startState);
+    }
     this.selectedAgentId = agentId;
   }
 
@@ -31,8 +35,10 @@ class SimEnv {
    */
   reset() {
     this.sim.reset();
-    const agent = this.sim.getAgent(this.selectedAgentId);
-    agent.setState(this.initialAgentState, true);
+    if (this.initialAgentState !== null) {
+      const agent = this.sim.getAgent(this.selectedAgentId);
+      agent.setState(this.initialAgentState, true);
+    }
   }
 
   changeAgent(agentId) {
@@ -112,6 +118,9 @@ class SimEnv {
    * @returns {Array} [magnitude, clockwise-angle (in radians)]
    */
   distanceToGoal() {
+    if (Object.keys(this.episode).length === 0) {
+      return [0, 0];
+    }
     let dst = this.episode.goal.position;
     let state = this.getAgentState();
     let src = state.position;
diff --git a/src/esp/bindings_js/modules/utils.js b/src/esp/bindings_js/modules/utils.js
index 252406b0be..2eb258cf45 100644
--- a/src/esp/bindings_js/modules/utils.js
+++ b/src/esp/bindings_js/modules/utils.js
@@ -91,3 +91,13 @@ export function getInfoSemanticUrl(mainUrl) {
   }
   return splits.join("/") + infoSemanticPath;
 }
+
+export function buildConfigFromURLParameters(config = {}) {
+  for (let arg of window.location.search.substr(1).split("&")) {
+    let [key, value] = arg.split("=");
+    if (key && value) {
+      config[key] = decodeURIComponent(value);
+    }
+  }
+  return config;
+}
diff --git a/src/esp/bindings_js/modules/web_demo.js b/src/esp/bindings_js/modules/web_demo.js
index de37f580ca..ab0dfbb06d 100644
--- a/src/esp/bindings_js/modules/web_demo.js
+++ b/src/esp/bindings_js/modules/web_demo.js
@@ -11,6 +11,7 @@ import {
 import SimEnv from "./simenv_embind";
 import TopDownMap from "./topdown";
 import NavigateTask from "./navigate";
+import { buildConfigFromURLParameters } from "./utils";
 
 class WebDemo {
   currentResolution = defaultResolution;
@@ -89,7 +90,12 @@ class WebDemo {
     return agentConfig;
   }
 
-  display(agentConfig = defaultAgentConfig, episode = defaultEpisode) {
+  display(agentConfig = defaultAgentConfig, episode = {}) {
+    const config = buildConfigFromURLParameters();
+    if (config.useDefaultEpisode) {
+      episode = defaultEpisode;
+    }
+
     this.initializeModules(agentConfig, episode);
 
     this.task.init();
diff --git a/src/esp/bindings_js/tests/utils.test.js b/src/esp/bindings_js/tests/utils.test.js
index 8a847fede0..d0d6bbacd4 100644
--- a/src/esp/bindings_js/tests/utils.test.js
+++ b/src/esp/bindings_js/tests/utils.test.js
@@ -1,4 +1,8 @@
-import { throttle, getInfoSemanticUrl } from "../modules/utils";
+import {
+  throttle,
+  getInfoSemanticUrl,
+  buildConfigFromURLParameters
+} from "../modules/utils";
 
 test("throttle should work properly", () => {
   let count = 0;
@@ -43,3 +47,14 @@ test("info semantic.json should have correct path", () => {
     expect(getInfoSemanticUrl(item)).toEqual(expectedInfoPaths[index]);
   });
 });
+
+test("configuration should be built from url parameters", () => {
+  delete window.location;
+  window.location = {};
+  window.location.search = "?a=b&c&d=true&e=1";
+  const config = buildConfigFromURLParameters();
+  expect(config.a).toEqual("b");
+  expect(config.c).toBeUndefined();
+  expect(config.d).toEqual("true");
+  expect(config.e).toEqual("1");
+});