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Rx Hands-On Labs published

Hi folks,

Yesterday, we released two hands-on labs on Rx both for .NET and for JS. The goal of those two documents is to present the reader with a gentle introduction into the subject, based on a series of incremental samples. This is based on a series on internal presentations we gave on the subject, being extended to various upcoming internal training events. Obviously we like to share this with the community, so here are the pointers:

Enjoy! As usual, all feedback is welcome. The idea is to evolve those documents based on feedback from different channels.

Please note that the example of Generate on page 9 of the .NET version is based on the upcoming release of Rx in which we have changed the order of the arguments to match the for-loop construct.

Until that release is available, replace
    IObservable<int> source = Observable.Generate(0, i => i < 5, i => i + 1, i => i * i);
With:
   IObservable<int> source = Observable.Generate(0, i => i < 5, i => i * i, i => i + 1);

Thanks,
-Bart

[Edit 7/15/2010]

Hi folks,

We really appreciate the active feedback. Some suggestions have been incorporated now. The links have been updated to refer to the new documents that have the changes applied.

Thanks,

-Bart

Comments

  • Anonymous
    July 07, 2010
    The comment has been removed

  • Anonymous
    July 07, 2010
    Sorry... Excercise 2 step 7 that is... I guess we all make mistakes. ;)

  • Anonymous
    July 07, 2010
    Rx JS HOL, page 27 says that   "function (term) { return searchWikipedia(term); }" eta-reduces to  "searchWikipedia(term)" but that should be "searchWikipedia" instead.

  • Anonymous
    July 08, 2010
    Johannes, see the comment regarding Generate at the end of the blog post....

  • Anonymous
    July 08, 2010
    On page 22,  the custom time stamp operator:        public static IObservable<T> LogTimestampedValues<T>(this IObservable<T> source, Action<T> onNext)        {            return source.Timestamp().Do(onNext).RemoveTimestamp();        } Should be: public static IObservable<T> LogTimestampedValues<T>(this IObservable<T> source, Action<Timestamped<T>> onNext)        {            return source.Timestamp().Do(onNext).RemoveTimestamp();        } Great document, great framework... keep up the brilliant work!

  • Anonymous
    July 08, 2010
    Hi, congratulations to this HOL. That's how documentation should look like!

  • Anonymous
    July 08, 2010
    This is terrific! I hope you guys will write more of these to cover advanced topics... but if not, this is still best documentation so far for Rx! Thanks.

  • Anonymous
    July 08, 2010
    The comment has been removed

  • Anonymous
    July 09, 2010
    Looks like an excellent intro so far! Minor typo (pg 7):  s/different form/different from/

  • Anonymous
    July 10, 2010
    This was a very well done tutorial; very helpful avoiding getting lost in the sea of available Observable combinators.  More please!

  • Anonymous
    July 10, 2010
    Exercise 2, step 9: Observable.Run returns void, but the example expects an "IDisposable subscription" return value.

  • Anonymous
    July 10, 2010
    Excercise 2, step 10's parameter order appears to also be based on the yet unreleased version of reactive extensions.

  • Anonymous
    July 10, 2010
    [Apologies if this is a duplicate, I received no success message the first time I clicked "Post".] Excercise 5, step 4: It seems better to .Throttle(...) before .DistinctUntilChanged(). With the order in the HOL, .DistinctUntilChanged() observes every typed value making it possible to get consecutive non-distinct notifications: Type "reactive" and wait for it to appear. Type backspace then 'e' within the throttle duration. Notice that "reactive" is displayed a second time. In the hypothetical spell-check application, this represents an unnecessary server call. If, however, .Throttle(...) is called first, .DistinctUntilChanged() only gets a chance to observe potentially submitted values. Consecutive duplicate values are not possible.

  • Anonymous
    July 10, 2010
    Excercise 8, step 5: After discussing the confusing cardinality of the webservice output (the webservice returns an array of words), the query shown in step five confuses the cardinality of the webservice output by naming the query range variable "word" [singular] rather than "words" or "wordList" [plural].

  • Anonymous
    July 12, 2010
    The first Windows Forms Rx sample does not work for me (page 14). ... moves.Subscribe(...) ... // blocked the UI I tried changing the current SynchronizationContext using SynchronizationContexts.WindowsForms but that didn't help either. Then I Intellisensed my way into SubscribeOnWindowsForms. That didn't work at first either. Only when supplying the actual form did it work without blocking the UI thread. ... moves.SubscribeOnWindowsForms(frm).Subscribe(...) ... what did I miss? :-)

  • Bent
  • Anonymous
    July 15, 2010
    I like your information. I have been looking for this type of information interesting and good

  • Anonymous
    July 16, 2010
    Excellent job! One of the best documentation/explanations I have ever seen.. Kudos to the team

  • Anonymous
    July 19, 2010
    Thx for this intro! As for js version: "If desired, clean-up of the event handler can be taken care of by calling Dispose on the object returned by the toObservable operator." I suppose Dispose should be called on object returned from Subscribe, not toObservable

  • Anonymous
    August 01, 2010
    Very nice work (For the Framework and Document also ... ) I Appreciate the People Behind this Terrific Framework , Go Microsoft Research Go !

  • Anonymous
    September 08, 2010
    I just want to let you guys know I heart Rx. :-)

  • Anonymous
    December 09, 2010
    Excellent intro. Can we have a "303" on some of the topics mentioned in the "202", e.g. more on error handling, .Publish, etc.

  • Anonymous
    February 07, 2011
    Page 14, 3.4, am getting an exception: A first chance exception of type 'System.EntryPointNotFoundException' occurred in System.Reactive.dll C:WindowsMicrosoft.NetassemblyGAC_MSILSystem.Reactivev4.0_1.0.4.0 Any ideas?

  • Anonymous
    February 07, 2011
    My mistake.  Had an older Rx installed.  Uninstalled both and reinstalled and all good.

  • Anonymous
    March 27, 2011
    One of the best HOLs I've ever seen. Well thought out, flows nicely.

  • Anonymous
    May 26, 2011
    if the subscription order is guaranteed, why do the output of the sample code below differ? My understanding was that both subscriptions should have produced the same result. Am I doing something wrong?    public class A02BufferAndWindowEx    {        internal static void Run()        {            var numbers = Enumerable.Range(1, 26);            Console.WriteLine("Take the input in buffer size of 10");            var buffNumbers = numbers.ToObservable().Buffer(10);            buffNumbers.Subscribe(Print);            Console.WriteLine();            buffNumbers.Subscribe(Print2);        }        private static void Print(IEnumerable<int> nums)        {            Console.WriteLine();            Console.Write("Buffer size: " + nums.Count() + "tItems: ");            nums.ToObservable().Subscribe(PrintSingle);        }        private static void PrintSingle(int num)        {            Console.Write(" " + num);        }        private static void Print2(IEnumerable<int> nums)        {            Console.WriteLine();            Console.Write("Buffer size: " + nums.Count() + "tItems: ");            foreach (var num in nums)            {                PrintSingle(num);            }        }    }

  • Anonymous
    April 25, 2012
    This HOL seems to be very out of date, e.g. System.CoreEx.dll no longer exists, and methods like subscriber.Run and Observable.GenerateWithTime have been removed. Can we have an updated HOL please?!