src/third_party/trace-viewer/third_party/Promises/reworked_APIs/IndexedDB/example/before.html

   1 <!DOCTYPE html>
   2 <html>
   3   <head>
   4     <title></title>
   5     <script>
   6       "use strict";
   7
   8       // Cribbed from:
   9       //   https://hacks.mozilla.org/2012/02/storing-images-and-files-in-indexeddb/
  10       var DB_NAME = "example";
  11       var OBJ_STORE_NAME = "objects";
  12       var VERSION = 1.0;
  13
  14       var db = null;
  15
  16       var onDBWriteable = function(e) {
  17         // Create a new Transaction in which to write
  18         var trans = db.transaction([OBJ_STORE_NAME], "readwrite");
  19         // Get the Object Store via the Transaction
  20         var store = trans.objectStore(OBJ_STORE_NAME);
  21
  22         // Write asynchronously
  23         var key = "thinger"
  24         var putRequest = store.put({ value: "stuff" }, key);
  25         putRequest.onsuccess = function(e) {
  26           console.log("writing successful");
  27
  28           // Read it back
  29           var getRequest = store.get(key);
  30           getRequest.onsuccess = function(e) {
  31             console.log("reading successful:", e.target.result);
  32           };
  33         };
  34       };
  35
  36       // Open up a DB against a particular version
  37
  38       // Note that this call is "async" in the sense that the request
  39       // deterministically fires the "upgradeneeded" and "success" events in a
  40       // later turn, giving us a chance to regsiter handlers here. There's
  41       // nothing in the API contract to indicat that this is so, however.
  42       var openRequest = this.indexedDB.open(DB_NAME, VERSION);
  43
  44       // If this is the first time we run, upgradeneeded is thrown and we can
  45       // create the object store.
  46       openRequest.onupgradeneeded = function (e) {
  47         console.log("database creation/upgrade needed");
  48         db = e.target.result;
  49
  50         console.log("creating object store:", OBJ_STORE_NAME)
  51         // Note that we can only call createObjectStore inside of an
  52         // upgradeneeded event.
  53         db.createObjectStore(OBJ_STORE_NAME);
  54       };
  55
  56       // We can only write once the DB is opened and upgraded/created. onsuccess
  57       // is always called after onupgradeneeded (if upgradeneeded is true).
  58       openRequest.onsuccess = function(e) {
  59         console.log("database opened successfully");
  60         db = e.target.result;
  61         console.log(db);
  62
  63         // Now write something to the Object Store
  64         onDBWriteable(e);
  65       };
  66
  67     </script>
  68   </head>
  69   <body></body>
  70 </html>