giuseppeg · February 26, 2018 16:50 · Feb 26, 2018
diff --git a/pspdfkit-indexeddb-cache-sample.js b/pspdfkit-indexeddb-cache-sample.js
@@ -0,0 +1,59 @@
+function getCache(name) {
+  return new Promise((resolve, reject) => {
+    const version = 1;
+    const request = indexedDB.open(name, version);
+
+    request.onsuccess = event => {
+      const db = event.target.result;
+
+      /*
+       * Returns a Promise that resolves with an object
+       * which contains { put, get } helpers.
+       */
+      resolve({
+        put: (key, value) =>
+          new Promise((resolve, reject) => {
+            try {
+              const result = db
+                .transaction([name], "readwrite")
+                .objectStore(name)
+                .put(value, key);
+
+              result.onsuccess = resolve;
+              result.onerror = reject;
+            } catch (e) {
+              reject(e);
+            }
+          }),
+
+        /*
+         * Returns a Promise that resolves with the `value` for `key`.
+         */
+        get: key =>
+          new Promise((resolve, reject) => {
+            try {
+              const result = db
+                .transaction([name])
+                .objectStore(name)
+                .get(key);
+
+              result.onsuccess = event => {
+                resolve(event.target.result);
+              };
+              result.onerror = reject;
+            } catch (e) {
+              reject(e);
+            }
+          })
+      });
+    };
+
+    // This will open/create the database.
+    request.onupgradeneeded = event => {
+      const db = event.target.result;
+      db.createObjectStore(name);
+    };
+
+    request.onerror = reject;
+  });
+}