store item to session storage

content.js

@@ -1,34 +1,58 @@
 chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
   if (request.message === "FETCH_IMAGE") {
-    // open gallery 
-    document.querySelector("#viewad-image") && 
-    document.querySelector("#viewad-image").click()
-
-    // settimeout to prevent side effects
-    setTimeout(() => {
-      // extract images
-      const imageContainer =
-        document.querySelectorAll(".ad-image-wrapper .ad-image img") ||
-        document.querySelectorAll("imagebox-thumbnail img") || false;
-
-
-      // create images array
-      const imageArray = Array.from(imageContainer) || null;
-      const imageSource = 
-        imageArray.length && 
-        imageArray.map(src => src.getAttribute("src"));
 
+    updateBackground = (results) => {
+      console.log('running update')
       // send results to background listener
       chrome.runtime.sendMessage({
         message: "SHOW_RESULTS",
         results: {
-          imageSource: imageSource
+          imageSource: results
         }
       });
+    }
+
+    // check storage
+    let resultsFromStorage = null;
+    const adElement = 
+      document.querySelector('.boxedarticle--details--full .align-right') && 
+      document.querySelector('.boxedarticle--details--full .align-right').innerText ||
+      false;
+
+    const adNumber = adElement && adElement.match(/[0-9]+/g) || false
+
+    if(adNumber.length) {
+      resultsFromStorage = sessionStorage.getItem(adNumber);
+    }
+
+    if(resultsFromStorage) {
+      updateBackground(JSON.parse(resultsFromStorage))
+
+    } else {
+      document.querySelector("#viewad-image") && 
+      document.querySelector("#viewad-image").click()
+
+      // settimeout to prevent side effects
+      setTimeout(() => {
+        // extract images
+        const imageContainer =
+          document.querySelectorAll(".ad-image-wrapper .ad-image img") ||
+          document.querySelectorAll("imagebox-thumbnail img") || false;
 
-      // close gallery
-      imageSource ? document.querySelector(".mfp-close").click() : null
+
+        // create images array
+        const imageArray = Array.from(imageContainer) || null;
+        const imageSource = 
+          imageArray.length && 
+          imageArray.map(src => src.getAttribute("src"));
+
+        sessionStorage.setItem(adNumber, JSON.stringify(imageSource));
+        console.log(imageSource)
+        updateBackground(imageSource);
+        // close gallery
+        imageSource ? document.querySelector(".mfp-close").click() : null
 
-    }, 1000)
+      }, 1000)
+    }
   }
 });