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New Post: IQueryable in IEnumerable

DCherubini — Mon, 29 Apr 2013 20:14:04 GMT

Hi,

Based on my understanding, it is as the documentation says. This is due to a quality of the object oriented programming languages named Polymorphism.

Basically, the IQueryable interface inherits from the IEnumerable interface. This allows you to sent a reference of type IEnumerable to an IQueryable implementation, return an IQueryable "as it was" an IEnumerable, etc. Hence, without the ToList invocation (which returns a List which is an IEnumerable implementation), an IQueryable would be returned instead "masked" as an IEnumerable.

When storing an IQueryable using a reference of type IEnumerable you can invoke its methods like you would on an IEnumerable but the logic that will be executed is the one defined in the IQueryable implementation, e. i. the behavior of the object will still be the one of an IQueryable.
The same applies to the IEnumerable extension methods because, basically, an extension method is an static method that uses the original methods of the object to work.

You can find more information about Polimorphism in the following MSDN article:

Polymorphism (C# Programming Guide)

Regards,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: IQueryable in IEnumerable

Andreas12345678 — Mon, 29 Apr 2013 14:01:43 GMT

Hi

In the documentation of Project silk it says following:

"In Mileage Stats, the implementation of the iReminderRepository calls Tolist before returning the iEnumerable<T>. This is to ensure that the query is executed inside the repository. If Tolist was not called, then the repository would return an iQueryable<T> and the database would not be accessed until something iterated over the iQueryable<T> object."

A code expample:

 public IEnumerable<Reminder> GetRemindersForVehicle(int vehicleId)
        {
            return this.GetDbSet<Reminder>()
                .Where(v => v.VehicleId == vehicleId)
                .ToList();
        }

Does that mean that even though the result is returned like IEnumerable, this would just be a container for a IQueryable, and if ToList() would not be called than one could be making calls on the IEnumerable as if it was a IQueryable?

Is this really right? It sounds wrong to me. If you where to make calls on the IEnumerable<Reminder>, that is returned if ToList isn't called, it would be the extension methods of IEnumerable that would be used and not IQueryable.

How can they clame that the function is returning a iQueryable<T> if ToList is not called, how is that possible?

It would be right if the method was returning a iQueryable<T> but it dosen't.

New Post: Models in different layers

DCherubini — Mon, 22 Apr 2013 19:03:39 GMT

Hi,

The documentation describes the handlers in the domain project as " a set of classes that implement the core behavior of the application ," where each handler is in charge of performing only one specific action. The controllers in the application delegate the logic of interacting with the domain layer to those handlers. Based on my understanding, the difference with the services is that they seem to be used only to obtain information from the domain without modifying it.

I believe you can find more information about the Domain layer implemented in Mileage Stats, in the following section of the documentation, where the handlers and models it uses are described:

Chapter 11 - Server-Side Implementation - Creating a Business Services Layer

I hope this helps,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: Models in different layers

Andreas12345678 — Fri, 19 Apr 2013 18:51:34 GMT

Thanks for answering.

I have one more question regarding Project silk.

The domain Project includes handlers but also Service-classes. What is it that separates a Handler from a Service?

New Post: Models in different layers

DCherubini — Wed, 17 Apr 2013 20:30:13 GMT

Hi,

Based on my understanding, the models located at MileageStats.Model are simple models representing the entities of the data base, and are used to retrieve and store the data in it thought Entity Framework. Meanwhile, the models located at MileageStats.Domain are the ones used by the controllers and views in the application, which also implement logic regarding the data they contain, like validation, etc. The application transforms one model into the other and backwards when passing information between layers (for example, the User model is converted in the UserService class.)

With that being said, I believe this architecture was implemented mostly based on a design decision, like separating the validation logic from the data access layer or decoupling the controllers / views from the underlying data base schema (while the models in MileageStats.Model can be mapped to the data base, this does not apply to some models in MileageStats.Domain.)

However, design decisions are often different for each application, so this design is not a must for every scenario.

I hope this helps,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: Models in different layers

Andreas12345678 — Wed, 17 Apr 2013 15:19:49 GMT

In Project silk there are Models in MileageStats.Model and also in the Business layer MileageStats.Domain.
Does anyone know why there is a class User in both Projects, the only difference is that User in MileageStats.Domain has attributes on it?

There is also a Reminder class in MileageStats.Model and a ReminderModel in MileageStats.Domain.

What is the Point of having it like this?
I guess I'm asking what's the use of MileageStats.Model Project? If the User model is updated with an additional property you need to add it on two places.

New Post: How to debug the Javascript code

Bunbuk — Wed, 10 Apr 2013 13:21:49 GMT

I was running the application with MVC 4, without MVC 3. I installed MVC 3 and reinstalled Mileage Stats. It works now, although I do not know why. I see all the .js files under the Debug folder.

New Post: How to debug the Javascript code

Bunbuk — Wed, 10 Apr 2013 08:54:43 GMT

Hi Damian,

Thank you really very much for your suggestion, but strangely I see no .js files under the debug folder in the list.
In the View Sources I only see the scripts mentioned at the end of the body tag, which are:

    <script src="//ajax.aspnetcdn.com/ajax/jQuery/jquery-1.6.1.min.js"></script>
    <script src="//ajax.aspnetcdn.com/ajax/jquery.ui/1.8.10/jquery-ui.min.js"></script>
    <script src="//ajax.aspnetcdn.com/ajax/jquery.templates/beta1/jquery.tmpl.min.js"></script>
    <script src="//cachedcommons.org/cache/jquery-bbq/1.2.1/javascripts/jquery-bbq-min.js"></script>
    <script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.7/jquery.validate.min.js"></script>
    <script src="//ajax.aspnetcdn.com/ajax/mvc/3.0/jquery.validate.unobtrusive.min.js"></script>
    <script src="//ajax.aspnetcdn.com/ajax/mvc/3.0/jquery.unobtrusive-ajax.min.js"></script>
    <script src="//ajax.cdnjs.com/ajax/libs/modernizr/1.7/modernizr-1.7.min.js"></script>

Might something be wrong in my configuration?

Atsushi

New Post: How to debug the Javascript code

DCherubini — Tue, 09 Apr 2013 16:24:07 GMT

Hi Atsushi,

In the Dashboard page, when using the developer tools in Internet Explorer 10, you can find the scripts in the View Sources button of the Script tab, named as mileagestats.js and mstats.xxxxx.js . There, I believe you can chose the file you want to debug and insert a breakpoint in it.

Regards,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: How to debug the Javascript code

Bunbuk — Fri, 05 Apr 2013 07:55:19 GMT

I am new to this area and maybe I am asking you a stupid question, but could anyone tell me how to debug the Javascript code of the Mileage Stats?

I opened the application with IE10, and opened the debug tool with F12. Then I clicked the View Sources button. I see there jquery...js files and modernizr...js file, but no mstats....js files.
I would like to set a breakpoint in a js file and to watch how the javascript code works, but how can I do it?

Atsushi

New Post: How to use Unity Block solve the type that contain parameter?

ThaiCarrot — Tue, 19 Mar 2013 09:08:43 GMT

Hi DCherubini,

Thanks, I was solve by inject the service rather than register it.

public UnitedExportDbContext(IConnectionString connectionString)

        : base(connectionString.GetConnectionString())
    {

    }

Because of I need dynamic not static. Is that correct way?

New Post: How to use Unity Block solve the type that contain parameter?

DCherubini — Mon, 18 Mar 2013 21:09:50 GMT

Hi,

Based on my understanding, you can also declare in the configuration file if you want to pass an specific value to a constructor parameter. For example, I believe you can do this by using the <constructor> , <param> and <value> XML elements. You can find more information about this in the following sections of the Unity documentation:

On the other hand, besides registering the types in the container using a configuration file, you should also be able to register them in the same way that you do in Prism. For example, I tried commenting the registration line of the IVehicleRepository interface from the configuration file and registering the type manually in the Global.asax.cs 's InitializeDependencyInjectionContainer method:

private static void InitializeDependencyInjectionContainer()
{
    container = new UnityContainerFactory().CreateConfiguredContainer();            
    var serviceLocator = new UnityServiceLocator(container);
    ServiceLocator.SetLocatorProvider(() => serviceLocator);
    DependencyResolver.SetResolver(new UnityDependencyResolver(container));

    // We register the type manually.
    container.RegisterType<IVehicleRepository, VehicleRepository>(new UnityHttpContextPerRequestLifetimeManager());
}

The result was that both the type registered manually and the types registered by the configuration file were correctly registered in the container.

Either of the two approaches should be useful to register the corresponding types as you need, but the first approach seems to be the cleaner one.

I hope this helps,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: How to use Unity Block solve the type that contain parameter?

ThaiCarrot — Sun, 17 Mar 2013 19:42:54 GMT

Hi,

Take a look at the code.

public class UnitedExportDbContext : DbContext, IUnitOfWork

{
    //public string connectionString="data source=.\\SQLExpress;Integrated Security=SSPI;Initial Catalog=UnitedExportDb";
    public UnitedExportDbContext(string connectionString)
        : base(connectionString)
    {

    }

With Prism I can do like the line below

container.RegisterType<IUnitOfWork, ReservationContext>(new ContainerControlledLifetimeManager(), new InjectionConstructor("FasterTableContext"));

Because of we register the types like following way.
<type type="UnitedExport.Data.IRepositoryInitializer, UnitedExport.Data" mapTo="UnitedExport.Data.Sql.RepositoryInitializer, UnitedExport.Data.Sql">

      <lifetime type="perRequest" />
    </type>
    <type type="UnitedExport.Data.IUnitOfWork, UnitedExport.Data" mapTo="UnitedExport.Data.Sql.UnitedExportDbContext, UnitedExport.Data.Sql">
      <lifetime type="perRequest" />
    </type>

I create the database like following code.

public virtual void Execute(ProvisioningRequestObj obj)

    {
        var repositoryInitializer = ServiceLocator.Current.GetInstance<IRepositoryInitializer>();
        repositoryInitializer.Initialize();     
    }

I got this error messages

{"The type String cannot be constructed. You must configure the container to supply this value."}

What I need is that the dynamic not lives within config file

New Post: Multi Tenant Web Based solution

ThaiCarrot — Wed, 06 Mar 2013 17:39:39 GMT

Hi there,

It would be nice if the silk team can provides a tutorial of Multi Tenant solution.

There's no way out with this solution.
http://litwarehr.codeplex.com/

Best,
WP

New Post: Are the DomainModel and DTO the same?

ThaiCarrot — Wed, 27 Feb 2013 21:17:07 GMT

Hi DCherubini,

Thanks, That is enough information.

Best Regards,
Weera

New Post: Hi Microsoft. Please...

ThaiCarrot — Wed, 27 Feb 2013 21:16:16 GMT

Hi DCherubini,

That was it, thanks. This site is really helpful

Best Regards,
Weera

New Post: Are the DomainModel and DTO the same?

DCherubini — Wed, 27 Feb 2013 20:13:48 GMT

Hi,

Based on my understanding, Domain Objects and Data Transfer Object are not the same, although they are similar to each other. While both are in charge of containing information, the main difference seems to be that a Data Transfer Object usually does not contain any logic; their only purpose is to contain data and their are usually used to send information between components. Instead, a Domain Object can also contain logic related to the information it contains (for example, validation logic, etc.)

Regarding this topic, I believe you could find the following article useful:

Data Transfer Object on MSDN

Regards,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: Hi Microsoft. Please...

DCherubini — Wed, 27 Feb 2013 18:56:31 GMT

Hi Weera,

I am not familiar with how to develop the kind of web applications you are describing, but if I am not mistaken, I believe that those applications are often defined as Multi-Tenant applications.

As far as I know, this kind of applications is not included in the scope of the Silk guidance. However, there are several blog post in the web describing different approaches to build Multi-Tenant applications that you might find useful to develop your solution.

As a starting point, I believe you might be interested in checking in following articles:

I hope this helps,

Damian Cherubini
http://blogs.southworks.net/dcherubini

New Post: Are the DomainModel and DTO the same?

ThaiCarrot — Wed, 27 Feb 2013 16:36:31 GMT

Hi,

I am wonder about the DomainModel and DTO. Are both the same?

Best Regards,
Weera

New Post: Hi Microsoft. Please...

ThaiCarrot — Tue, 26 Feb 2013 11:23:21 GMT

Hi,

Could you give me a brief description. How do I implement web base app as same as the CodePlex.

I need only features is that when end user come to my site then he/she register to the site, after that automatically generates a web site for each end user. It is sub domain of my site.

For example.

www.Test.com

sub so main

www.Test.com/UserOne

www.Test.com/UserOne

I don't know how the logic should be.

Best Regards,
Weera