MetaChildrenColumn not created when using a DomainService with a one to Many Mapping [Answered]RSS

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  sdemalet

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  MetaChildrenColumn not created when using a DomainService with a one to Many Mapping

  Sep 20, 2013 06:32 AM|sdemalet|LINK

  I am using the Entity Framework and a Domain Service  and I have a one-to-many mapping between two tables

  I am trying to use the Dynamic Child grid example by Steve Naughton but My Data column is an EntityCollection rathen than a MetaChildrenColumn.

  Has anyone got an equivalent  solution 

   var metaChildColumn = Column as MetaChildrenColumn; (this is where it is falling over as my column is an EntityCollection)

  var metaForeignKeyColumn = metaChildColumn.ColumnInOtherTable as MetaForeignKeyColumn;
  
      if (metaChildColumn != null && metaForeignKeyColumn != null)
      {
          GridDataSource.DomainServiceTypeName = typeof(DomainService).FullName;
           MetaTable table = metaChildColumn.ChildTable;

  If I just try and use the EntityCollection then it is strongly typed to the actual child entity and I am looking for a more generic solution.

  Has anyone come across this and found an equivalent solution?

  Thanks
  
  

• • Reply
  sjnaughton

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  Re: MetaChildrenColumn not created when using a DomainService with a one to Many Mapping

  Sep 21, 2013 03:09 PM|sjnaughton|LINK

  Hi Sophie, (I tried to e-mail you but i am in france at the moment ad can't send for some reason.), sorry I don’t as MS have not adding the insert and update parameters to the DomainServiceDataSource, I may have a way of getting it to work but not had the time to try it out.

   

  Just in case you want to try yourself I was thinking of adding on inserting and on updating event to the child grid see the EF ManyToMany_Edit field template for how to do that and then add the parameters there J

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

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  Re: MetaChildrenColumn not created when using a DomainService with a one to Many Mapping

  Sep 26, 2013 11:10 AM|sdemalet|LINK

  Hi there, I have found a generic way of doing this though so far only for Viewing - I have not tried updating the gridview yet.

  This is how I managed to get it to work.

  public partial class ChildGrid : FieldTemplateUserControl
      {
          protected MetaTable DisplayTable { get; set; }
          private String[] DisplayColumns { get; set; }
          private String DisplayTableName { get; set; }
  
  
          protected void Page_Init(object sender, EventArgs e)
          {
              var attribute = Column.Attributes.OfType<ShowChildColumnsAttribute>().SingleOrDefault();
  
   
              if (attribute != null)
              {
                  if (attribute.DisplayColumns.Length > 0)
                      DisplayColumns = attribute.DisplayColumns;
  
                  DisplayTableName = attribute.TableName;
              }
              DisplayTable = Column.Table.Model.GetTable(DisplayTableName);
              GridView1.ColumnsGenerator = new FieldTemplateRowGenerator(DisplayTable, DisplayColumns);
  
              // setup the GridViewDataKeys
  
              var keys = new String[DisplayTable.PrimaryKeyColumns.Count];
              int i = 0;
              foreach (var keyColumn in DisplayTable.PrimaryKeyColumns)
              {
                  keys[i] = keyColumn.Name;
                  i++;
              }
              GridView1.DataKeyNames = keys;
              GridView1.SetMetaTable(DisplayTable);
  
          }
  
          protected override void OnDataBinding(EventArgs e)
          {
              // Get the real entity from the wrapper
              object entity = Row;
  
              // Get the collection of reservations for this customer and make sure it's loaded
              var entityCollection = (RelatedEnd) Column.EntityTypeProperty.GetValue(entity, null);
  
              entityCollection.Load();
  
              var objectQuery = (ObjectQuery) entityCollection.GetType().GetMethod(
                  "CreateSourceQuery").Invoke(entityCollection, null);
              
              GridView1.DataSource = objectQuery;
  
          }
  
  
         // use this to navigate to the Details page for our Child Grid
         // gets the primary keys from the grid datakeys and uses these to
         // navigate to the details page for the table in question
          
          protected void GridSelectedIndexChanged(object sender, EventArgs e)
          {
              // Get the currently selected row using the SelectedRow property.
              string primarykeyvalues = string.Empty;
  
              // now let's build up the primary keys for the redirect
              if (GridView1.SelectedDataKey != null)
              {
                  var keys = GridView1.SelectedDataKey.Values;
  
                  foreach (DictionaryEntry key in keys)
                  {
                      primarykeyvalues = primarykeyvalues + key.Key;
                      primarykeyvalues = primarykeyvalues + "=" + key.Value + "&";
                  }
                  primarykeyvalues = primarykeyvalues.TrimEnd('&', ' ');
              }
              Response.Redirect("../" + DisplayTable + "/DetailsSubGridViews.aspx?" + primarykeyvalues);
   
          }

  This seems to work quite nicely so far...