Support for bookmarking

Author: pontusmelke

src/v1/session.js

@@ -79,15 +79,21 @@ class Session {
    *
    * @returns {Transaction} - New Transaction
    */
-  beginTransaction() {
+  beginTransaction(bookmark) {
     if (this._hasTx) {
       throw newError("You cannot begin a transaction on a session with an "
       + "open transaction; either run from within the transaction or use a "
       + "different session.")
     }
 
     this._hasTx = true;
-    return new Transaction(this._connectionPromise, () => {this._hasTx = false}, this._onRunFailure());
+    return new Transaction(this._connectionPromise, () => {
+      this._hasTx = false},
+      this._onRunFailure(), bookmark, (bookmark) => {this._lastBookmark = bookmark});
+  }
+
+  lastBookmark() {
+    return this._lastBookmark;
   }
 
   /**

src/v1/transaction.js

@@ -30,19 +30,25 @@ class Transaction {
    * @param {Promise} connectionPromise - A connection to use
    * @param {function()} onClose - Function to be called when transaction is committed or rolled back.
    * @param errorTransformer callback use to transform error
+   * @param bookmark optional bookmark
    */
-  constructor(connectionPromise, onClose, errorTransformer) {
+  constructor(connectionPromise, onClose, errorTransformer, bookmark, onBookmark) {
     this._connectionPromise = connectionPromise;
     let streamObserver = new _TransactionStreamObserver(this);
+    let params = {};
+    if (bookmark) {
+      params = {bookmark: bookmark};
+    }
     this._connectionPromise.then((conn) => {
       streamObserver.resolveConnection(conn);
-      conn.run("BEGIN", {}, streamObserver);
+      conn.run("BEGIN", params, streamObserver);
       conn.discardAll(streamObserver);
     }).catch(streamObserver.onError);
 
     this._state = _states.ACTIVE;
     this._onClose = onClose;
     this._errorTransformer = errorTransformer;
+    this._onBookmark = onBookmark || (() => {});
   }
 
   /**
@@ -114,6 +120,14 @@ class _TransactionStreamObserver extends StreamObserver {
       this._hasFailed = true;
     }
   }
+
+  onCompleted(meta) {
+    super.onCompleted(meta);
+    let bookmark = meta.bookmark;
+    if (bookmark) {
+      this._tx._onBookmark(bookmark);
+    }
+  }
 }
 
 /** internal state machine of the transaction*/

test/v1/transaction.test.js

@@ -214,4 +214,17 @@ describe('transaction', function() {
         done();
       });
   });
+
+  it('should provide bookmark on commit', function (done) {
+    // When
+    var tx = session.beginTransaction();
+    expect(session.lastBookmark()).not.toBeDefined();
+    tx.run("CREATE (:TXNode1)");
+    tx.run("CREATE (:TXNode2)");
+    tx.commit()
+      .then(function () {
+        expect(session.lastBookmark()).toBeDefined();
+        done();
+      });
+  });
 });