grouping columns into class to pass into FieldTemplate sporadic problem

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mkaty

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81 Points

27 Posts

grouping columns into class to pass into FieldTemplate sporadic problem

Nov 04, 2008 05:06 PM|mkaty|LINK

Hi All,

I'm new to Dynamic Data and am trying something a little strange. I wrote a custom FieldTemplate that expects a class data type. The class is just a grouping of the actual entity columns - I copy the columns into the class and return the instance in the class getter. In the class setter I update the actual columns with the new values. That's it. This works very well most of the time. However sometimes when I go to update, my class is updated to the correct values - but the original properties are not. I stepped through with the debugger and when it does not work I can see the original properties getting set to the correct values and then immediately reset to something else. Again, this happens only sometimes. Sometimes it works properly. Any ideas as to what's going on?

Thanks much.

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sjnaughton

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Re: grouping columns into class to pass into FieldTemplate sporadic problem

Nov 05, 2008 09:25 AM|sjnaughton|LINK

I think you are doing something simlar to what I did as an example for an other post have a look at this: Dynamic Data Compound Column

If it's not what you are doing let me know [:D]

See my blog C# Bits | Twitter @sjnaughton
Always seeking an elegant solution.

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mkaty

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81 Points

27 Posts

Re: grouping columns into class to pass into FieldTemplate sporadic problem

Nov 05, 2008 01:14 PM|mkaty|LINK

Hi Steve,

Thanks for the reply. I am doing almost exactly what you did in the Compound Column. My class does not contain anything too complicated - just a couple of strings and bools and a date. Yet my db table, which is a large table with foreign keys, etc, is still not getting updated correctly every now and then.

When I update a plain column I see that the column setter gets hit 3 times - 1. change null to new value, 2. change null to old value, 3. change old value to new value. Looks like two instances of my table entity got created. Makes sense.

When I update my custom class (and it's at the non-working stage) I see that the column (original - not my class) setter gets hit 5 times - 1. change null to new value, 2 change new value to null, 3. change null to old value 4. change old value to null 5. change null to null so do nothing. OnCreated gets hit multiple times, more than the two that I would expect.

I'm trying to figure out what causes steps 2 and 4 happen...

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mkaty

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27 Posts

Re: grouping columns into class to pass into FieldTemplate sporadic problem

Nov 05, 2008 03:33 PM|mkaty|LINK

With a bit more research it looks like LINQ thinks there's a concurrency conflict going on...

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ricka6

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Re: grouping columns into class to pass into FieldTemplate sporadic problem

Nov 06, 2008 12:03 AM|ricka6|LINK

Hey mkaty,

Would it be possible to come up with the simplest possible repro and post it here? Bonus points if you use NorthWind or AdventureWorks DB - Or just a couple simple tables and the T-SQL to create/populate them.

Rick -ASP.Net UE @RickAndMSFT Rick on MVC, WebAPI and Azure

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mkaty

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81 Points

27 Posts

Re: grouping columns into class to pass into FieldTemplate sporadic problem

Nov 06, 2008 12:06 PM|mkaty|LINK

Here are the bits of code (in bold) I added to the DynamicDataFutures sample to reproduce the problem. If I add UpdateCheck=UpdateCheck.Never to the attributes for the 3 columns concerned the update works every time.

NorthwindPartials.cs:

    [Serializable]
    public class CombinedColumns
    {
        private string _firstName;
        private string _lastName;
        private System.DateTime? _hireDate;


        public CombinedColumns(string first, string last, System.DateTime? date)
        {
            _firstName = first;
            _lastName = last;
            _hireDate = date;
        }


        public string firstName { get { return _firstName; } set { _firstName = value; } }
        public string lastName { get { return _lastName; } set { _lastName = value; } }
        public System.DateTime? hireDate { get { return _hireDate; } set { _hireDate = value; } }
    }


    [MetadataType(typeof(Employee_MD))]
    public partial class Employee {
     public CombinedColumns MyCombinedColumns
       {
            get
            {
                return new CombinedColumns(this.FirstName, this.LastName, this.HireDate);
            }
            set
            {
                if (value != null)
                {
                    CombinedColumns cc = (CombinedColumns)value;


                    this.FirstName = cc.firstName;
                    this.LastName = cc.lastName;
                    this.HireDate = cc.hireDate;
                }
            }
        }


        public class Employee_MD {


            [UIHint("CombinedColumns")]
            public object MyCombinedColumns { get; set; }
            [DataType(DataType.Url)]
            public object PhotoPath { get; set; }
        }
    }

CombinedColumns_Edit.aspx.cs  - the aspx just has the 3 textboxes with labels

    public partial class CombinedColumns_EditField : System.Web.DynamicData.FieldTemplateUserControl {
        protected void Page_Load(object sender, EventArgs e) {
        }

        protected override void OnDataBinding(EventArgs e)
        {
            base.OnDataBinding(e);

            CombinedColumns cc = (CombinedColumns)this.FieldValue;
            if(cc != null)
            {
                TextBox1.Text = cc.firstName;
                TextBox2.Text = cc.lastName;
                TextBox3.Text = (cc.hireDate ?? DateTime.Now).ToShortDateString();
            }
        }

        protected override void ExtractValues(IOrderedDictionary dictionary) {

            CombinedColumns cc = new CombinedColumns(TextBox1.Text, TextBox2.Text, DateTime.Now);
            dictionary[Column.Name] = cc;
        }

    }

Added Custom Edit Page for the Employees table: only change to DetailsView1 is AutoGenerateRows = false and the only DynamicField is MyCombinedColumns.

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