Cache upgrade buttons

gorge.js

@@ -243,8 +243,6 @@ function renderResources() {
   return renderLines(list);
 }
 
-const buildingButtons = {}
-
 function displayBuildings() {
   const count = buildingCount();
 
@@ -259,13 +257,13 @@ function displayBuildings() {
         continue;
       }
       belongings[key].visible = true;
-      let button = buildingButtons[key].button;
+      let button = cache.buildingButtons[key].button;
       button.classList.remove("hidden");
     }
 
-    let button = buildingButtons[key].button;
-    let name = buildingButtons[key].name;
-    let cost = buildingButtons[key].cost;
+    let button = cache.buildingButtons[key].button;
+    let name = cache.buildingButtons[key].name;
+    let cost = cache.buildingButtons[key].cost;
 
     const buildingCost = costOfBuilding(key, count);
 
@@ -311,7 +309,7 @@ function switchShowOwnedUpgrades() {
 function displayUpgrades(owned) {
   if (owned) {
     Object.entries(ownedUpgrades).forEach(([key, val]) => {
-      let button = document.querySelector("#upgrade-" + key);
+      let button = cache.upgradeButtons[key];
       if (val) {
         button.classList.remove("hidden");
       } else {
@@ -321,7 +319,7 @@ function displayUpgrades(owned) {
   }
   else {
     for (let id of remainingUpgrades) {
-      let button = document.querySelector("#upgrade-" + id);
+      let button = cache.upgradeButtons[id];
 
       if (ownedUpgrades[id]) {
         button.classList.add("hidden");
@@ -425,7 +423,12 @@ function setup() {
 
 }
 
+const cache = {};
+
 function initializeCaches() {
+
+  const buildingButtons = {};
+
   for (const [key, value] of Object.entries(belongings)) {
 
     let button = document.querySelector("#building-" + key);
@@ -439,6 +442,15 @@ function initializeCaches() {
     }
   }
 
+  cache.buildingButtons = buildingButtons;
+
+  const upgradeButtons = {};
+
+  Object.keys(upgrades).forEach(key => {
+    upgradeButtons[key] = document.querySelector("#upgrade-" + key);
+  });
+
+  cache.upgradeButtons = upgradeButtons;
 }
 
 function unlockAtStart() {