Comment Feed for Channel 9 - Silverlight TV 11: Dynamically Loading XAPs with MEF

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

Ben Hayat — Mon, 01 Mar 2010 22:19:00 GMT

You guys Rock! This is such a clean solution for developing large app.

John, seriously you and Glenn should write a book on "Building large app with MEF & SL". I love the way John always stops at the right point to clear certain points. He did that in his book too.

posted by Ben Hayat

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

cesnek — Tue, 02 Mar 2010 11:38:52 GMT

Why is SL application split to XAPs. Why not split to DLL (one XAP shell and many DLL to download).

Split to DLL will be more "compatible and smooth" if you have single source code for SL and WPF application.

posted by cesnek

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

zenbeats — Tue, 02 Mar 2010 14:09:19 GMT

john what's in that koozie?

Having this flexibility will allow for more sophisticated applicaitons while maintaining a positive user experience by delivering functionality on demand.

Thanks for the video, glad to know this is on the road map.

posted by zenbeats

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

Ben Hayat — Tue, 02 Mar 2010 15:33:49 GMT

>>john what's in that koozie?<<

Looks like a Bud can to me!

posted by Ben Hayat

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

jopapa — Tue, 02 Mar 2010 18:19:42 GMT

Having separate XAPs allows you to keep the proejcts completely decoupled perhaps to build them at different times without affecting each other (just one possibility). Another option is when you have one team building an architecture while another team or company builds a plug in for your architecture. The disconnected XAPs is a more elegant solution in many ways than separate DLLs as it gives you more opportunity to keep your code fully decoupled.

posted by jopapa

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

jopapa — Tue, 02 Mar 2010 18:21:00 GMT

Ben & zenbeats - I'm not telling what's in the koozie

posted by jopapa

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

Ben Hayat — Tue, 02 Mar 2010 20:12:59 GMT

Well, it's a white Can,

you're smiling in that shot (looks like you're feeling good)

and you're hanging on to table table pretty tightly,

I'll say it's a Cold one.

“if it looks like a duck and sounds like a duck, it’s probably a duck”

posted by Ben Hayat

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

gblock — Wed, 03 Mar 2010 00:43:42 GMT

Cesnek

XAPs provide a way to groups of related functionality into a simple deployment unit. Without such a unit you have to manage all dependencies at a very fine-grained level.

Glenn

posted by gblock

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

gblock — Wed, 03 Mar 2010 22:00:28 GMT

Thanks Ben. We are currently planning a MEF book, we'll have to see if John is interested in authoring a chapter or two.

Glenn

posted by gblock

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

dsoltesz — Thu, 04 Mar 2010 19:24:50 GMT

Ran into an issue with composition happening more than once for a given element and that's because I was using page navigation and if the user navigated to a page, navigated away and then return to page, I was trying to load xap again. So what I did is made a change to the AddXap method to check if the aggregateCatalog already contains the deploymentCatalog

public void AddXap(string uri)

{

DeploymentCatalog catalog;

if (!_catalogs.TryGetValue(uri, out catalog))

{

catalog = new DeploymentCatalog(uri);

catalog.DownloadAsync();

_catalogs[uri] = catalog;

}

if (!_aggregateCatalog.Catalogs.Contains(catalog))

{

_aggregateCatalog.Catalogs.Add(catalog);

}

posted by dsoltesz

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

jmcmullan — Tue, 09 Mar 2010 16:14:56 GMT

John, Glenn

Thanks for the great post, helped me get my head round a few issues concerning MEF!

I have a question tho, is it possible to have an independant navigation framework working in one or more of the child XAPs and import the required navigation elements into the host XAP to navigate to said child XAP?

Sorry if this is confusing, we are considering using MEF for a couple of large projects we're about to start and this is one of the requirements.

If more info about the projects would help you answer the question please feel free to contact me directly.

Kind regards,

Jonny

posted by jmcmullan

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

gblock — Sun, 21 Mar 2010 21:10:36 GMT

Hi Jonny

It is possible to integrate MEF with Navigation in SL4 and even to navigate cross-xaps. I demo that in my recent MIX talk which the code that I demo is also available. I posted a link to the code in the comments.

The session is here: http://live.visitmix.com/MIX10/Sessions/CL52

posted by gblock

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

sdeepak — Mon, 29 Mar 2010 22:04:03 GMT

I would like to know following

- Does MEF support dynamic XAP loading of two Silverlight Application where one has "windowless" parameter set to true and

another with "windowless" parameter as false.

I have situation where I have to use Silverlight DataForms to enter Japanese Characters (IME support) and I also have HTML content to be displayed.

For HTML content - windowless parameter needs to be true and for IME support the windowless parameter should be false.

So, application using HTML content and IME characters cannot co-exist in a single XAP.

Any insight to above issue will be appreciated.

sdeepak

posted by sdeepak

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

gblock — Fri, 09 Apr 2010 06:17:10 GMT

I don't see why it wouldn't work as the DeploymentCatalog does not have any UI dependencies. Haven't tried it though

posted by gblock

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

mgraham — Sun, 11 Apr 2010 01:32:50 GMT

All of this is AWESOME...

Question: is there a way to avoid downloading assemblies that are already included in the base XAP or in one of the dynamically downloaded XAPs?

Related Question: can I now (in Silverlight 4) enumerate the assemblies that an assembly references?

posted by mgraham

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

mgraham — Wed, 14 Apr 2010 11:03:57 GMT

Here is an excellent description of the deployment catalog including information on how to create a XAP that references assemblies, but does not include them (copy local = false).

http://mef.codeplex.com/wikipage?title=DeploymentCatalog&referringTitle=Using%20Catalogs

The main caveat is that a XAP that does include these assemblies must already be loaded before loading such a XAP (otherwise when MEF enumerates the contained types, Silverlight will throw an exception about the assembly or referenced assemblies not being loaded).

posted by mgraham

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

StuckInVB — Mon, 10 May 2010 00:46:37 GMT

Any chance of getting the sample code in VB?

I am failing to get it a C# conversion that works.

Thanks

posted by StuckInVB

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

Ceyhun — Sun, 23 May 2010 13:53:53 GMT

Hi Glenn,

All of that is absolutely fantastic and I am trying to leverage every part of it (especially the DeploymentCatalogService approach, although I fear (and hope) that it will be overridden with a true distributable in the near future).

However, these samples are a little bit misleading; SatisfyImports() is not asynchronous and you have already loaded all the catalogs before the button is pressed; if you put AddXap() to the button click nothing will work; and this is exacly the scenario that we want: nothing should be pre-loaded unless it is going to be used. Essentially, you pre-load everything in the main page and if the user quick enough and the server slow enough it will break as well.

In short I would expect IPartImportsSatisfiedNotification to be more closely related to an async SatisfyImports.

Regards,
Ceyhun

posted by Ceyhun

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

syed ijlal haider 15606 — Sun, 19 Sep 2010 18:17:23 GMT

Here is an excellent description of the deployment catalog including information on how to create a XAP. thanks
url: http://www.livetv.pk
id: 15606

posted by syed ijlal haider 15606

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

Muhammad Arslan — Sat, 25 Sep 2010 09:08:57 GMT

thanks for giving nice website

posted by Muhammad Arslan

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

tahmad81 — Fri, 08 Oct 2010 10:07:48 GMT

good !!!

posted by tahmad81

Re: Silverlight TV 11: Dynamically Loading XAPs with MEF

tahmad81 — Mon, 11 Oct 2010 05:28:57 GMT

I have one some questions Glenn would you please be able to answer!

If i create different class libraries in my single silverlight application, means there is only one xap and in my SL application i am importing controls from other library projects , so what is the benefit ? because the xap is downloaded at client at srartup so how can i say its a dynamic loading .

In multiple xap project i can understand becasue control referenced in the other xap is loaded dynamically at the moment when i need that control .

Regards.

posted by tahmad81