remove extra clear cache button and isolate cache code (#609)

* remove extra clear cache button

* isolate cache code

* changes

examples/demo.js

@@ -200,42 +200,8 @@ window.onload = function() {
     }
   });
 
-  if ('serviceWorker' in navigator) {
+  setupCache();
-    navigator.serviceWorker.register('sw.js', { scope: '/examples/' })
+  
-      .then(function(registration) {
-        const installingWorker = registration.installing;
-        installingWorker.onstatechange = () => {
-          console.log(installingWorker)
-          if (installingWorker.state === 'installed') {
-            location.reload();
-          }
-        }
-        console.log('Registration successful, scope is:', registration.scope);
-      })
-      .catch(function(error) {
-        console.log('Service worker registration failed, error:', error);
-      });
-  }
-
-  if ('serviceWorker' in navigator) {
-    caches.keys().then(function(cacheNames) {
-      cacheNames.forEach(function(cacheName) {
-        $("#clear-cache").append(" " + cacheName);
-      });
-    });
-  }
-
-  $("#clear-cache").click(function() {
-    if ('serviceWorker' in navigator) {
-      caches.keys().then(function(cacheNames) {
-        cacheNames.forEach(function(cacheName) {
-          caches.delete(cacheName);
-        });
-      });
-    }
-    location.reload();
-  });
-
   function updatePreviews(src) {
     $('#addStep img').remove();
 

examples/index.html

@@ -21,6 +21,7 @@
   <script src="lib/defaultHtmlStepUi.js" charset="utf-8"></script>
   <script src="lib/defaultHtmlSequencerUi.js" charset="utf-8"></script>
   <script src="lib/intermediateHtmlStepUi.js" charset="utf-8"></script>
+  <script src="lib/cache.js" charset="utf-8"></script>
   <script src="demo.js" charset="utf-8"></script>
   <!-- for crop module: -->
   <script src="../node_modules/imgareaselect/jquery.imgareaselect.dev.js"></script>
@@ -185,12 +186,6 @@
     <button><i class="fa fa-arrow-circle-o-up"></i></button>
   </form>
 
-
-
-  <footer>
-    <hr style="margin:20px;"><center><a class="color:grey;" id="clear-cache">Clear offline cache</a></center>
-  </footer>
-
   <script type="text/javascript">
     $(function() {
       var sequencer;

examples/lib/cache.js

@@ -0,0 +1,37 @@
+var setupCache = function() {
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.register('sw.js', { scope: '/examples/' })
+      .then(function(registration) {
+        const installingWorker = registration.installing;
+        installingWorker.onstatechange = () => {
+          console.log(installingWorker)
+          if (installingWorker.state === 'installed') {
+            location.reload();
+          }
+        }
+        console.log('Registration successful, scope is:', registration.scope);
+      })
+      .catch(function(error) {
+        console.log('Service worker registration failed, error:', error);
+      });
+  }
+
+  if ('serviceWorker' in navigator) {
+    caches.keys().then(function(cacheNames) {
+      cacheNames.forEach(function(cacheName) {
+        $("#clear-cache").append(" " + cacheName);
+      });
+    });
+  }
+
+  $("#clear-cache").click(function() {
+    if ('serviceWorker' in navigator) {
+      caches.keys().then(function(cacheNames) {
+        cacheNames.forEach(function(cacheName) {
+          caches.delete(cacheName);
+        });
+      });
+    }
+    location.reload();
+  });
+}

examples/lib/sw.js

@@ -0,0 +1,35 @@
+const staticCacheName = 'image-sequencer-static-v3';
+
+self.addEventListener('install', event => {
+  console.log('Attempting to install service worker');
+});
+
+self.addEventListener('activate', function(e) {
+  console.log('[ServiceWorker] Activate');
+  e.waitUntil(
+    caches.keys().then(function(cacheNames) {
+      return Promise.all(
+        cacheNames.filter(function(cacheName){
+          return cacheName.startsWith('image-sequencer-') &&
+                 cacheName != staticCacheName;
+        }).map(function(cacheName){
+          return caches.delete(cacheName);
+        })
+      );
+    })
+  );      
+});
+
+self.addEventListener('fetch', function(event) {
+  event.respondWith(
+    caches.open(staticCacheName).then(function(cache) {
+      return cache.match(event.request).then(function (response) {
+        return response || fetch(event.request).then(function(response) {
+          if(event.request.method == "GET")
+            cache.put(event.request, response.clone());
+          return response;
+        });
+      });
+    })
+  );
+});