how to get data from the server

07-03-2009 2:05 AM |

How do I effect a transfer of data from the server to the client using the following code?  Do I need to write a method on the server side?

Note that the class FeedbackView does not exist in my DataModel.

 

 

public FeedbackPage()
        {
            InitializeComponent();
            
            PersonalWebsiteDomainContext context = new PersonalWebsiteDomainContext();
            this.DataContext = context;

            List query = (from f in context.Feedbacks
                                        join a in context.Articles on f.ArticleID equals a.ArticleID
                                        select new FeedbackView
                                        {
                                            FeedbackID = f.FeedbackID,
                                            ParentID = f.ParentID,
                                            ArticleID = f.ArticleID,
                                            ArticleName = a.Title,
                                            Date = f.Date,
                                            SenderName = f.SenderName,
                                            SenderIPAddress = f.SenderIPAddress,
                                            Comment = f.Comment, 
                                            Approved = f.Approved
                                        }).ToList();

            dg.ItemsSource = query;
        }

        
        protected class FeedbackView
        {
            public int FeedbackID {get; set;}
            [Key]
            public int ParentID {get; set;}
            public int ArticleID {get; set;}
            public string ArticleName {get; set;}
            public DateTime Date {get; set;}
            public string SenderName {get; set;}
            public string SenderIPAddress {get; set;}
            public string Comment {get; set;}
            public bool Approved { get; set; }
        }

  

Re: how to get data from the server

07-04-2009 12:34 AM |

you will have to write some type of service for the silverlight client to call and get the data.  The call to the server is async so dont be suprised.

Re: how to get data from the server

07-04-2009 2:52 AM |

You need to call a method on the context before you create "query" else "context.Feedback" will be empty. Normally you could create a LINQ-query and pass it to the DomainContext. Another way is to implement a specific query method in the DomainService which will be exposed via the DomainContext and cal be called in your client. See the QueryAttribute. Anyway when you use the DomainDataSource you can declare this in XAML.

Have you considered using a viewmodel that wraps the PersonalWebsiteDomainContext, like http://stackoverflow.com/questions/744474/combining-net-ria-services-and-mvvm-in-silverlight-3-0. This way you move the query in the viewmodel.

Re: how to get data from the server

07-06-2009 12:28 PM |

 Alternatively Sam, for a quick mock-up (unsecure), you can create xml as your data, and either embed it as a resource in your SL project, or use a webclient to retrieve it from a remote location via http.  You can then use your existing code to query the xml as an xmldatasource.  This not a productised solution but will get you up and running quickly to prototype the rest of your SL app.

 Michael

 

...Mark this as answer if it has been helpful.

Re: how to get data from the server

07-08-2009 1:26 AM |

 Thanks all for the replies.  I was on vacation this weekend.  
OK here is what I did.  It mostly works but I'm not sure it's the best way.  The problem I'm having is using the IQueryable object. See commented section of code where I set the ItemsSource of the datagrid.

1.) Server:  Made a file for my "...View" classes:

 

namespace PersonalWebsite1.Web
{
    public class FeedbackView
    {
        [Key]
        public int FeedbackID { get; set; }
        public int ParentID { get; set; }
        public int ArticleID { get; set; }
        public string ArticleName { get; set; }
        public DateTime Date { get; set; }
        public string SenderName { get; set; }
        public string SenderIPAddress { get; set; }
        public string Comment { get; set; }
        public bool Approved { get; set; }
    }
}

2.) Server: marked my DomainService class with the partial modifer (Why is this class not generated with the partial modifier?).  Created another file, same class, like this:

 

namespace PersonalWebsite1.Web
{
    public partial class PersonalWebsiteDomainService : LinqToEntitiesDomainService

    {
        public IQueryable GetFeedbackView()
        {
            var query = (from f in Context.Feedback
                join a in Context.Articles on f.ArticleID equals a.ArticleID
                select new FeedbackView
                {
                    FeedbackID = f.FeedbackID,
                    ParentID = f.ParentID,
                    ArticleID = f.ArticleID,
                    ArticleName = a.Title,
                    Date = f.Date,
                    SenderName = f.SenderName,
                    SenderIPAddress = f.SenderIPAddress,
                    Comment = f.Comment,
                    Approved = f.Approved
                }).AsQueryable();
            
            return query;
        }
    }
}

  

3) Client:  Set the ItemsSource of the datagrid as follows:

  

namespace PersonalWebsiteAdmin.Views
{
    public partial class FeedbackPage : BasePage
    {
        public FeedbackPage()
        {
            InitializeComponent();
            PersonalWebsiteDomainContext Context = new PersonalWebsiteDomainContext();

            //Does not work.  
            IQueryable query = Context.FeedbackViews.AsQueryable().Where(f => f.FeedbackID < 7);
            Context.LoadFeedbackView(query,null);
            dg.ItemsSource = query;
            

            // Works
            //Context.LoadFeedback();
            //dg.ItemsSource = Context.Feedbacks;
        }

 

 

Re: how to get data from the server

07-08-2009 1:32 PM |

 Excellent! Thank you Theo.