Re: elemental2 indexeddb example?

On Monday, January 28, 2019 at 12:49:41 AM UTC+1, rhodebump wrote:

Thanks, I did make some progress.   I dug around a little in the javadoc and found the IndexedDbGlobal, which I was able to use to create a new database.

elemental2.indexeddb.IDBFactory indexedDB = elemental2.indexeddb.IndexedDbGlobal.indexedDB;

elemental2.indexeddb.IDBOpenDBRequest openDBRequest = indexedDB.open("mydbtest", 1.0);

So far so good.

With a open database call, I get a returned object of elemental2.indexeddb.IDBOpenDBRequest (https://static.javadoc.io/com.google.elemental2/elemental2-indexeddb/1.0.0-RC1/elemental2/indexeddb/IDBOpenDBRequest.html)

In the google documentation that I have found that describes the indexedDB open operation, https://developers.google.com/web/ilt/pwa/working-with-indexeddb#opening_a_database

They provide the following code:

  var dbPromise = idb.open('test-db2', 1, function(upgradeDb) {
    console.log('making a new object store');
    if (!upgradeDb.objectStoreNames.contains('firstOS')) {
      upgradeDb.createObjectStore('firstOS');
    }
  });

Note that this is using the IndexedDB Promised library, not the IndexedDB API (see https://developers.google.com/web/ilt/pwa/working-with-indexeddb#comparison_of_indexeddb_api_and_indexeddb_promised_library)

Fwiw, I'd rather use https://developer.mozilla.org/en-US/docs/Web/API/IndexedDB_API as a reference.

 

I want to register a function to execute when the database is upgraded.  I see there is a openDBRequest.onupgradeneeded(), but I just can't the syntax right.

elemental2.indexeddb.IDBFactory indexedDB = elemental2.indexeddb.IndexedDbGlobal.indexedDB;

elemental2.indexeddb.IDBOpenDBRequest openDBRequest = indexedDB.open("mydbtest", 1.0);

//how to i call a function for upgrade?  I want to create some object stores.

openDBRequest. onupgradeneeded = doUpgrade();

That would be something like:

openDBRequest.onupgradeneeded = new OnupgradeneededFn() {
  @Override
  public Object onInvoke(IDBVersionChangeEvent event) {
    doUpgrade();
    return Js.undefined(); // that value will likely be ignored anyway
  }
};

or, using a lambda:

openDBRequest.onupgradeneeded = event -> {
  doUpgrade();
  return Js.undefined();
};

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