Integrated queue in DataSet

lib/DataSet.js

@@ -1,4 +1,5 @@
 var util = require('./util');
+var Queue = require('./Queue');
 
 /**
  * DataSet
@@ -35,6 +36,11 @@ var util = require('./util');
  *                             {Object.<String, String} type
  *                                              A map with field names as key,
  *                                              and the field type as value.
+ *                             {Object} queue   Queue changes to the DataSet,
+ *                                              flush them all at once.
+ *                                              Queue options:
+ *                                              - {number} delay  Delay in ms, null by default
+ *                                              - {number} max    Maximum number of entries in the queue, Infinity by default
  * @constructor DataSet
  */
 // TODO: add a DataSet constructor DataSet(data, options)
@@ -77,6 +83,15 @@ function DataSet (data, options) {
   if (data) {
     this.add(data);
   }
+
+  // change the dataset in a queued one
+  if (this._options.queue) {
+    var queue = {
+      replace: ['add', 'update', 'remove']
+    };
+    if (typeof this._options.queue === 'object') util.extend(queue, this._options.queue);
+    Queue.extend(this, queue);
+  }
 }
 
 /**

lib/Queue.js

@@ -5,7 +5,7 @@
  *            - delay: number    When a number, the queue will be flushed
  *                               automatically after an inactivity of this delay
  *                               in milliseconds.
- *                               When false (default), the queue is not flushed
+ *                               Default value is null.
  *            - max: number      When the queue exceeds the given maximum number
  *                               of entries, the queue is flushed automatically.
  *                               Default value of max is Infinity.
@@ -13,8 +13,8 @@
  */
 function Queue(options) {
   // options
-  this.delay = options && typeof options.delay === 'number' ? options.delay : false;
-  this.max   = options && typeof options.max === 'number' ? options.max : Infinity;
+  this.delay = options && typeof options.delay === 'number' ? options.delay : null;
+  this.max   = options && typeof options.max === 'number'   ? options.max   : Infinity;
 
   // properties
   this._queue = [];

test/DataSet.test.js

@@ -1,12 +1,13 @@
 var assert = require('assert');
 var moment = require('moment');
 var DataSet = require('../lib/DataSet');
+var Queue = require('../lib/Queue');
 
 var now = new Date();
 
-// TODO: improve DataSet tests, split up in one test per function
 describe('DataSet', function () {
   it('should work', function () {
+    // TODO: improve DataSet tests, split up in one test per function
 
     var data = new DataSet({
       type: {
@@ -174,4 +175,65 @@ describe('DataSet', function () {
     // TODO: test subscribing to events
 
   });
+
+  it('should queue and flush changes', function () {
+    var options = {queue: true};
+    var dataset = new DataSet([
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ], options);
+
+    assert.deepEqual(dataset.get(), [
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ]);
+
+    dataset.add({id: 3, content: 'Item 3'});
+    dataset.update({id: 1, content: 'Item 1 (updated)'});
+    dataset.remove(2);
+
+    assert.deepEqual(dataset.get(), [
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ]);
+
+    dataset.flush();
+
+    assert.deepEqual(dataset.get(), [
+      {id: 1, content: 'Item 1 (updated)'},
+      {id: 3, content: 'Item 3'}
+    ]);
+  });
+
+  it('should queue and flush changes after a timeout', function (done) {
+    var options = {queue: {delay: 100}};
+    var dataset = new DataSet([
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ], options);
+
+    assert.deepEqual(dataset.get(), [
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ]);
+
+    dataset.add({id: 3, content: 'Item 3'});
+    dataset.update({id: 1, content: 'Item 1 (updated)'});
+    dataset.remove(2);
+
+    assert.deepEqual(dataset.get(), [
+      {id: 1, content: 'Item 1'},
+      {id: 2, content: 'Item 2'}
+    ]);
+
+    setTimeout(function () {
+      assert.deepEqual(dataset.get(), [
+        {id: 1, content: 'Item 1 (updated)'},
+        {id: 3, content: 'Item 3'}
+      ]);
+
+      done();
+    }, 200)
+  });
+
 });

test/Queue.test.js

@@ -2,7 +2,7 @@ var assert = require('assert');
 var Queue = require('../lib/Queue');
 
 describe('Queue', function () {
-  it('queue, queue actions', function () {
+  it('queue actions', function () {
     var queue = new Queue();
 
     var count = 0;
@@ -17,7 +17,7 @@ describe('Queue', function () {
     assert.equal(count, 1);
   });
 
-  it('queue, queue actions with a delay', function (done) {
+  it('queue actions with a delay', function (done) {
     var queue = new Queue({delay: 25});
 
     var count = 0;
@@ -35,7 +35,7 @@ describe('Queue', function () {
     }, 50);
   });
 
-  it('queue, queue multiple actions with a delay', function (done) {
+  it('queue multiple actions with a delay', function (done) {
     var queue = new Queue({delay: 100});
 
     var count = 0;
@@ -63,6 +63,24 @@ describe('Queue', function () {
     }, 50);
   });
 
+  it('flush when the configured maximum is exceeded', function () {
+    var queue = new Queue({max: 4});
+
+    var count = 0;
+    function inc() {
+      count++;
+    }
+
+    queue.queue(inc);
+    queue.queue(inc);
+    assert.equal(count, 0);
+
+    queue.queue(inc);
+    queue.queue(inc);
+    queue.queue(inc);
+    assert.equal(count, 5);
+  });
+
   it('queue actions with args', function () {
     var queue = new Queue();