[add] service worker & offline reader

assets/lib/idb-keyval.js

@@ -0,0 +1,50 @@
+function _slicedToArray(t,n){return _arrayWithHoles(t)||_iterableToArrayLimit(t,n)||_unsupportedIterableToArray(t,n)||_nonIterableRest()}function _nonIterableRest(){throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.")}function _unsupportedIterableToArray(t,n){if(t){if("string"==typeof t)return _arrayLikeToArray(t,n);var r=Object.prototype.toString.call(t).slice(8,-1);return"Object"===r&&t.constructor&&(r=t.constructor.name),"Map"===r||"Set"===r?Array.from(t):"Arguments"===r||/^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(r)?_arrayLikeToArray(t,n):void 0}}function _arrayLikeToArray(t,n){(null==n||n>t.length)&&(n=t.length);for(var r=0,e=new Array(n);r<n;r++)e[r]=t[r];return e}function _iterableToArrayLimit(t,n){var r=null==t?null:"undefined"!=typeof Symbol&&t[Symbol.iterator]||t["@@iterator"];if(null!=r){var e,o,u=[],i=!0,a=!1;try{for(r=r.call(t);!(i=(e=r.next()).done)&&(u.push(e.value),!n||u.length!==n);i=!0);}catch(t){a=!0,o=t}finally{try{i||null==r.return||r.return()}finally{if(a)throw o}}return u}}function _arrayWithHoles(t){if(Array.isArray(t))return t}function _typeof(t){return _typeof="function"==typeof Symbol&&"symbol"==typeof Symbol.iterator?function(t){return typeof t}:function(t){return t&&"function"==typeof Symbol&&t.constructor===Symbol&&t!==Symbol.prototype?"symbol":typeof t},_typeof(t)}!function(t,n){"object"===("undefined"==typeof exports?"undefined":_typeof(exports))&&"undefined"!=typeof module?n(exports):"function"==typeof define&&define.amd?define(["exports"],n):n((t="undefined"!=typeof globalThis?globalThis:t||self).idbKeyval={})}(this,(function(t){"use strict";function n(t){return new Promise((function(n,r){t.oncomplete=t.onsuccess=function(){return n(t.result)},t.onabort=t.onerror=function(){return r(t.error)}}))}function r(t,r){var e=indexedDB.open(t);e.onupgradeneeded=function(){return e.result.createObjectStore(r)};var o=n(e);return function(t,n){return o.then((function(e){return n(e.transaction(r,t).objectStore(r))}))}}var e;function o(){return e||(e=r("keyval-store","keyval")),e}function u(t,r){return t.openCursor().onsuccess=function(){this.result&&(r(this.result),this.result.continue())},n(t.transaction)}t.clear=function(){var t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:o();return t("readwrite",(function(t){return t.clear(),n(t.transaction)}))},t.createStore=r,t.del=function(t){var r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:o();return r("readwrite",(function(r){return r.delete(t),n(r.transaction)}))},t.delMany=function(t){var r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:o();return r("readwrite",(function(r){return t.forEach((function(t){return r.delete(t)})),n(r.transaction)}))},t.entries=function(){var t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:o();return t("readonly",(function(r){if(r.getAll&&r.getAllKeys)return Promise.all([n(r.getAllKeys()),n(r.getAll())]).then((function(t){var n=_slicedToArray(t,2),r=n[0],e=n[1];return r.map((function(t,n){return[t,e[n]]}))}));var e=[];return t("readonly",(function(t){return u(t,(function(t){return e.push([t.key,t.value])})).then((function(){return e}))}))}))},t.get=function(t){var r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:o();return r("readonly",(function(r){return n(r.get(t))}))},t.getMany=function(t){var r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:o();return r("readonly",(function(r){return Promise.all(t.map((function(t){return n(r.get(t))})))}))},t.keys=function(){var t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:o();return t("readonly",(function(t){if(t.getAllKeys)return n(t.getAllKeys());var r=[];return u(t,(function(t){return r.push(t.key)})).then((function(){return r}))}))},t.promisifyRequest=n,t.set=function(t,r){var e=arguments.length>2&&void 0!==arguments[2]?arguments[2]:o();return e("readwrite",(function(e){return e.put(r,t),n(e.transaction)}))},t.setMany=function(t){var r=arguments.length>1&&void 0!==arguments[1]?arguments[1]:o();return r("readwrite",(function(r){return t.forEach((function(t){return r.put(t[1],t[0])})),n(r.transaction)}))},t.update=function(t,r){var e=arguments.length>2&&void 0!==arguments[2]?arguments[2]:o();return e("readwrite",(function(e){return new Promise((function(o,u){e.get(t).onsuccess=function(){try{e.put(r(this.result),t),o(n(e.transaction))}catch(t){u(t)}}}))}))},t.values=function(){var t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:o();return t("readonly",(function(t){if(t.getAll)return n(t.getAll());var r=[];return u(t,(function(t){return r.push(t.value)})).then((function(){return r}))}))},Object.defineProperty(t,"__esModule",{value:!0})}));
+
+/**
+ * Custom IDB Convenience Functions Wrapper
+ **/
+const IDB = (function () {
+  let { get, del, entries, update, keys } = idbKeyval;
+
+  return {
+    async set(key, newValue) {
+      let changeObj = {};
+      await update(key, (oldValue) => {
+        if (oldValue != null) changeObj.oldValue = oldValue;
+        changeObj.newValue = newValue;
+        return newValue;
+      });
+      return changeObj;
+    },
+
+    get(key, defaultValue) {
+      return get(key).then((resp) => {
+        return defaultValue && resp == null ? defaultValue : resp;
+      });
+    },
+
+    del(key) {
+      return del(key);
+    },
+
+    find(keyRegExp, includeValues = false) {
+      if (!(keyRegExp instanceof RegExp)) throw new Error("Invalid RegExp");
+
+      if (!includeValues)
+        return keys().then((allKeys) =>
+          allKeys.filter((key) => keyRegExp.test(key))
+        );
+
+      return entries().then((allItems) => {
+        const matchingKeys = allItems.filter((keyVal) =>
+          keyRegExp.test(keyVal[0])
+        );
+        return matchingKeys.reduce((obj, keyVal) => {
+          const [key, val] = keyVal;
+          obj[key] = val;
+          return obj;
+        }, {});
+      });
+    },
+  };
+})();

assets/lib/sw-helper.js

@@ -0,0 +1,60 @@
+const SW = (function () {
+  // Helper Function
+  function randomID() {
+    return "00000000000000000000000000000000".replace(/[018]/g, (c) =>
+      (c ^ (crypto.getRandomValues(new Uint8Array(1))[0] & (15 >> (c / 4))))
+        .toString(16)
+        .toUpperCase()
+    );
+  }
+
+  // Variables
+  let swInstance = null;
+  let outstandingMessages = {};
+
+  navigator.serviceWorker.addEventListener("message", ({ data }) => {
+    let { id } = data;
+    data = data.data;
+
+    console.log("[SW] Received Message:", { id, data });
+    if (!outstandingMessages[id])
+      return console.warn("[SW] Invalid Outstanding Message:", { id, data });
+
+    outstandingMessages[id](data);
+    delete outstandingMessages[id];
+  });
+
+  async function install() {
+    // Register Service Worker
+    swInstance = await navigator.serviceWorker.register("/sw.js");
+    swInstance.onupdatefound = (data) =>
+      console.log("[SW.install] Update Found:", data);
+
+    // Wait for Registration / Update
+    let serviceWorker =
+      swInstance.installing || swInstance.waiting || swInstance.active;
+
+    // Await Installation
+    await new Promise((resolve) => {
+      serviceWorker.onstatechange = (data) => {
+        console.log("[SW.install] State Change:", serviceWorker.state);
+        if (serviceWorker.state == "activated") resolve();
+      };
+      if (serviceWorker.state == "activated") resolve();
+    });
+  }
+
+  function send(data) {
+    if (!swInstance?.active) return Promise.reject("Inactive Service Worker");
+    let id = randomID();
+
+    let msgPromise = new Promise((resolve) => {
+      outstandingMessages[id] = resolve;
+    });
+
+    swInstance.active.postMessage({ id, data });
+    return msgPromise;
+  }
+
+  return { install, send };
+})();