Bindable LINQ vs. continuous LINQ

Question

What are the major difference between bindable LINQ and continuous LINQ?

•Bindable LINQ: www.codeplex.com/bindablelinq

•Continuous LINQ: www.codeplex.com/cli

Answer 1

Their are 2 problems both these packages try to solve: Lack of a CollectionChanged event and Dynamic result sets. There is one additional problem bindable solves, additional automatic event triggers.

---

The First Problem both packages aim to solve is this:

Objects returned by a LINQ query do not provide CollectionChanged events.

Continuous LINQ automatically does this to all queries, with no change:

from item in theSource select item ;

Bindable LINQ does this when you add .asBindable to your query Source Object:

from item in theSource.AsBindable() select item ;

---

The Second Problem both packages aim to solve is:

Result sets returned from a LINQ Query are static.

Normally when you do a LINQ Query your result set is unchanged until you do a new query. With these two packages, your result set is updated whenever the source is updated. (bad for performance, good for realtime updates)

Example

var theSource = new ContinuousCollection();
var theResultSet = from item in theSource where item.Age > 25 select item;
//theResultSet.Count would equal 0.

Because your using Bindable or Continuous LINQ, you could modify theSource, and theResultSet would automatically include the new item.

theSource.Add(new Customer("Bob", "Barker" , 35, Gender.Male)); //Age == 35
//theResultSet.Count would now equal 1.

---

The Additional Problem Bindable LINQ offers: (Quoting directly from their own page)

contactsListBox.ItemsSource = from c in customers
                              where c.Name.StartsWith(textBox1.Text)
                              select c;

Bindable LINQ will detect that the query relies on the Text property of the TextBox object, textBox1. Since the TextBox is a WPF control, Bindable LINQ knows to subscribe to the TextChanged event on the control.

The end result is that as the user types, the items in the query are re-evaluated and the changes appear on screen. No additional code is needed to handle events.