Dynamic Data - Hiding Tables on the Default.aspx page

This is just a write up of an answer to a question on the Dynamic Data forum, so here's the solution.

First of all we need an attribute class:

[AttributeUsage(AttributeTargets.Class)]
public class HideTableInDefaultAttribute : Attribute
{
    public Boolean Hide { get; private set; }

    public HideTableInDefaultAttribute(Boolean hide)
    {
        Hide = hide;
    }
    // this will allow us to have a default set to false
    public static HideTableInDefaultAttribute Default = 
        new HideTableInDefaultAttribute(false);
}

Listing 1 - HideTableIndefaultAttribute

And now the code in the Default.aspx:

protected void Page_Load(object sender, EventArgs e)
{
    System.Collections.IList visibleTables = Global.DefaultModel.VisibleTables;
    if (visibleTables.Count == 0)
        throw new InvalidOperationException(
            @"There are no accessible tables. 
            Make sure that at least one data model is 
            registered in Global.asax and scaffolding is 
            enabled or implement custom pages.");

    //Menu1.DataSource = visibleTables;
    //Menu1.DataBind();

    // Hiding tables
    var tablesMain = (from t in Global.DefaultModel.VisibleTables
                     where !t.Attributes.OfType<HideTableInDefaultAttribute>().
                        DefaultIfEmpty(HideTableInDefaultAttribute.Default).First().Hide
                     orderby t.DisplayName
                     select t).ToList();

    Menu1.DataSource = tablesMain;
    Menu1.DataBind();

}

Listing 2 - Default.aspx Page_Load event handler

Note in the where clause the DefaultIfEmpty which allows you to specify the default value to return if no value found. This means that you will always get a value and the default value will have the Hide property set to false because of the Default keyword in the Attribute definition.

Now some sample metadata:

// note the differance in the result of using 
// ScaffoldTable(false) over HideTableInDefault(true)
[ScaffoldTable(false)]
public partial class Category
{
}

[HideTableInDefault(true)]
public partial class EmployeeTerritory 
{
}

[HideTableInDefault(true)]
public partial class Product
{
}

Listing 3 - sample metadata

Figure 1 - Limited Tables list from Northwind

Figure 2 - See how the Products column has a foreign key link

Figure 3 - Note that the Category column has no link

If you look at each of the above Figures you will see the differences between a ScaffoldTable(false) and a HideTableInDefault(true). It's also worth noting that if you omit a table from the Model you either get a ForeignKey column of no column if it was a children column, so this makes using the above two methods the best way of hiding tables in the Default.aspx page.

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Note: You will need to change the Connection String in the web.config

Dynamic Data - Hiding Columns in selected PageTemplates

This is a return to IAutoFieldGenrators, what we are trying to do is specify what page template to hide columns on.

First the Attribute class:

[AttributeUsage(AttributeTargets.Property)]
public class HideColumnInAttribute : Attribute
{
    public PageTemplate[] PageTemplates { get; private set; }

    public HideColumnInAttribute()
    {
        PageTemplates = new PageTemplate[0];
    }

    public HideColumnInAttribute(params PageTemplate[] lookupTable)
    {
        PageTemplates = lookupTable;
    }

    public static HideColumnInAttribute Default = new HideColumnInAttribute();
}

public enum PageTemplate
{
    Details,
    Edit,
    Insert,
    List,
    ListDetails,
    // add any custom page templates here
}

Listing 1 - HideColumnIn attribute

here you pass an array of pages that the column should be hidden in.

[MetadataType(typeof(OrderMetadata))]
public partial class Order
{
    public class OrderMetadata
    {
        [DisplayName("Order Date")]
        [HideColumnIn
            (
                PageTemplate.Details, 
                PageTemplate.Edit, 
                PageTemplate.Insert
            )]
        public Object OrderDate { get; set; }
    }
}

Listing 2 - sample metadata for Northwind's Orders table

In Listing 2 we are saying that the OrderDate column should NOT be shown on the Details, Edit and Insert pages.

Next we need an IAutoFieldGenerator class for this feature.

public class HideColumnFieldsManager : IAutoFieldGenerator
{
    protected MetaTable _table;
    protected PageTemplate _currentPage;

    public HideColumnFieldsManager(MetaTable table, PageTemplate currentPage)
    {
        _table = table;
        _currentPage = currentPage;
    }

    public ICollection GenerateFields(Control control)
    {
        var oFields = new List<DynamicField>();

        foreach (var column in _table.Columns)
        {
            // carry on the loop at the next column  
            // if scaffold table is set to false or DenyRead
            if (!column.Scaffold ||
                column.IsLongString ||
                column.IsHidden(_currentPage))
                continue;

            var f = new DynamicField();

            f.DataField = column.Name;
            oFields.Add(f);
        }
        return oFields;
    }
}

public static class ExtensionMethods
{
    public static Boolean IsHidden(this MetaColumn column, PageTemplate currentPage)
    {
        var hideIn = column.Attributes.OfType<HideColumnInAttribute>().DefaultIfEmpty(new HideColumnInAttribute()).First() as HideColumnInAttribute;
        return hideIn.PageTemplates.Contains(currentPage);
    }
}

Listing 3 - the IAutoFieldGenerator class

!Important: It should be noted that all that is required if you already have an IAutoFieldGenerator class is to add the column.Hidden(_currentPage) test in the if statement that skips columns and also have the Extension methods class.

This IAutoFieldGenerator class and Extension methods class in Listing 3 simply test to see if the column is NOT to be shown on the current page passed in the constructor.

A bit more of an explanation is required for what is going on in the Extension method IsHidden. I tried using the DefaultIfEmpty with the Default method but could not get it to work so I added the if null statement and set the hideIn to the defalut value if null.

protected void Page_Init(object sender, EventArgs e)
{
    DynamicDataManager1.RegisterControl(DetailsView1);
    table = DetailsDataSource.GetTable();
    DetailsView1.RowsGenerator = new HideColumnFieldsManager(table, PageTemplate.Details);
}

Listing 4 - sample implementation on the Details page

protected void Page_Init(object sender, EventArgs e)
{
    DynamicDataManager1.RegisterControl(GridView1, true /*setSelectionFromUrl*/);
    DynamicDataManager1.RegisterControl(DetailsView1);
    MetaTable table = GridDataSource.GetTable();
    GridView1.ColumnsGenerator = new HideColumnFieldsManager(table, PageTemplate.ListDetails);
    DetailsView1.RowsGenerator = new HideColumnFieldsManager(table, PageTemplate.ListDetails);
}

Listing 5 - sample implementation in the ListDetails page

Now each page needs to have a RowsGenerator or ColumnGenerator added as in Listings 4 & 5.

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Hope this helps

Steve

Dynamic Data – Custom Metadata Providers *** UPDATED 20081110 ***

This is really just an addition to Matt Berseth's article Dynamic Data And Custom Metadata Providers from August 24, 2008, all I wanted to do was add the same features to the Table/Class not just the Columns/Properties. So you can see the full explanation over at Matt Berseth's blog. So here are the listings:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Web;

public class DefaultAttributesTypeDescriptionProvider : System.ComponentModel.TypeDescriptionProvider
{
    private Type Type { get; set; }

    public DefaultAttributesTypeDescriptionProvider(Type type)
        : this(type, TypeDescriptor.GetProvider(type))
    {
        this.Type = type;
    }

    public DefaultAttributesTypeDescriptionProvider(Type type, TypeDescriptionProvider parentProvider)
        : base(parentProvider)
    {
        this.Type = type;
    }

    public override ICustomTypeDescriptor GetTypeDescriptor(Type objectType, object instance)
    {
        return new DefaultAttributesTypeDescriptor(base.GetTypeDescriptor(objectType, instance), this.Type);
    }
}

Listing 1 – TypeDescriptorProvider

No change in Listing 1 from what Matt has already done just some renaming to make it a bit clearer to me what's going on.

using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Reflection;

public class DefaultAttributesTypeDescriptor : CustomTypeDescriptor
{
    private Type Type { get; set; }

    public DefaultAttributesTypeDescriptor(ICustomTypeDescriptor parent, Type type)
        : base(parent)
    {
        this.Type = type;
    }

    /// <summary>
    /// Returns the collection of attributes for a given table
    /// </summary>
    /// <returns>AttributeCollection</returns>
    public override AttributeCollection GetAttributes()
    {
        AttributeCollection baseAttributes = base.GetAttributes();

        if (baseAttributes.OfType<DisplayNameAttribute>().FirstOrDefault() == null)
        {
            List<Attribute> extraAttributes = new List<Attribute>();

            // generate the display name
            String friendlyDisplayName = base.GetClassName().ToTitleFromPascal();

            // add it to the list
            extraAttributes.Add(new DisplayNameAttribute(friendlyDisplayName));

            // only create a new collection if it is necessary
            return AttributeCollection.FromExisting(baseAttributes, extraAttributes.ToArray());
        }
        else
        {
            return baseAttributes;
        }
    }

    /// <summary>
    /// Returns a collection of properties (columns) for the type,
    /// each with attributes for that table
    /// </summary>
    /// <returns>PropertyDescriptorCollection</returns>
    public override PropertyDescriptorCollection GetProperties()
    {
        List<PropertyDescriptor> propertyDescriptors = new List<PropertyDescriptor>();

        foreach (PropertyDescriptor propDescriptor in base.GetProperties())
        {
            List<Attribute> newAttributes = new List<Attribute>();

            // Display Name Rules ...
            // If the property doesn't already have a DisplayNameAttribute defined
            // go ahead and auto-generate one based on the property name
            if (!propDescriptor.HasAttribute<DisplayNameAttribute>())
            {
                // generate the display name
                String friendlyDisplayName = propDescriptor.Name.ToTitleFromPascal();

                // add it to the list
                newAttributes.Add(new DisplayNameAttribute(friendlyDisplayName));
            }

            // Display Format Rules ...
            // If the property doesn't already have a DisplayFormatAttribute defined
            // go ahead and auto-generate one based on the property type
            if (!propDescriptor.HasAttribute<DisplayFormatAttribute>())
            {
                // get the default format for the property type
                String displayFormat = propDescriptor.PropertyType.GetDisplayFormat();

                // add it to the list
                newAttributes.Add(new DisplayFormatAttribute() { DataFormatString = displayFormat });
            }

            propertyDescriptors.Add(new WrappedPropertyDescriptor(propDescriptor, newAttributes.ToArray()));
        }

        // return the descriptor collection
        return new PropertyDescriptorCollection(propertyDescriptors.ToArray(), true);
    }

    private class WrappedPropertyDescriptor : PropertyDescriptor
    {
        private PropertyDescriptor _wrappedPropertyDescriptor;

        public WrappedPropertyDescriptor(PropertyDescriptor wrappedPropertyDescriptor, Attribute[] attributes)
            : base(wrappedPropertyDescriptor, attributes)
        {
            _wrappedPropertyDescriptor = wrappedPropertyDescriptor;
        }

        public override bool CanResetValue(object component)
        {
            return _wrappedPropertyDescriptor.CanResetValue(component);
        }

        public override Type ComponentType
        {
            get { return _wrappedPropertyDescriptor.ComponentType; }
        }

        public override object GetValue(object component)
        {
            return _wrappedPropertyDescriptor.GetValue(component);
        }

        public override bool IsReadOnly
        {
            get { return _wrappedPropertyDescriptor.IsReadOnly; }
        }

        public override Type PropertyType
        {
            get { return _wrappedPropertyDescriptor.PropertyType; }
        }

        public override void ResetValue(object component)
        {
            _wrappedPropertyDescriptor.ResetValue(component);
        }

        public override void SetValue(object component, object value)
        {
            _wrappedPropertyDescriptor.SetValue(component, value);
        }

        public override bool ShouldSerializeValue(object component)
        {
            return _wrappedPropertyDescriptor.ShouldSerializeValue(component);
        }
    }
}

Listing 2 – CustomTypeDescriptor

Here all I’ve done is again some renaming and add a GetAttributes method which returns the attributes on the class/table. The section is marked in BOLD ITALIC for emphasis. What it does is check to see if the DisplayNameAttriburte is set and if not then auto generates it.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.DynamicData;
using Microsoft.Web.DynamicData;

public static class HelperExtansionMethods
{
    public static ColumnOrderAttribute ColumnOrdering(this MetaColumn column)
    {
        return column.Attributes.OfType<ColumnOrderAttribute>().DefaultIfEmpty(ColumnOrderAttribute.Default).First();
    }

    public static Boolean IsHidden(this MetaColumn column, PageTemplate currentPage)
    {
        var hideIn = column.Attributes.OfType<HideColumnInAttribute>().DefaultIfEmpty(new HideColumnInAttribute()).First() as HideColumnInAttribute;
        return hideIn.PageTemplates.Contains(currentPage);
    }

    /// <summary>
    /// Converts a Pascal type Name to Title
    /// i.e. MyEmployees becomes My Employees
    ///      OrderID becomes Order ID etc
    /// </summary>
    /// <param name="s">String to convert</param>
    /// <returns>Title String</returns>
    public static String ToTitleFromPascal(this String s)
    {
        // remove name space
        String s0 = Regex.Replace(s, "(.*\\.)(.*)", "$2");

        // add space before Capital letter
        String s1 = Regex.Replace(s0, "[A-Z]", " $&");

        // replace '_' with space
        String s2 = Regex.Replace(s1, "[_]", " ");

        // replace double space with single space
        String s3 = Regex.Replace(s2, "  ", " ");

        // remove and double capitals with inserted space
        String s4 = Regex.Replace(s3, "(?<before>[A-Z])\\s(?<after>[A-Z])", "${before}${after}");

        // remove and double capitals with inserted space
        String sf = Regex.Replace(s4, "^\\s", "");

        // force first character to upper case
        return sf.ToTitleCase();
    }

    public static String ToTitleCase(this String text)
    {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < text.Length; i++)
        {
            if (i > 0)
            {
                if (text.Substring(i - 1, 1) == " " || 
                    text.Substring(i - 1, 1) == "\t" || 
                    text.Substring(i - 1, 1) == "/")
                    sb.Append(text.Substring(i, 1).ToString().ToUpper());
                else
                    sb.Append(text.Substring(i, 1).ToString().ToLower());
            }
            else
                sb.Append(text.Substring(i, 1).ToString().ToUpper());
        }

        return sb.ToString();
    }

    public static Boolean HasAttribute<T>(this PropertyDescriptor descriptor) where T : Attribute
    {
        Boolean value = false;
        for (int i = 0; i < descriptor.Attributes.Count && !value; i++)
        {
            value = (descriptor.Attributes[i] is T);
        }

        return value;
    }

    public static String GetDisplayFormat(this Type type)
    {
        string defaultFormat = "{0}";

        if (type == typeof(DateTime) || type == typeof(Nullable<DateTime>))
        {
            defaultFormat = "{0:d}";
        }
        else if (type == typeof(decimal) || type == typeof(Nullable<decimal>))
        {
            defaultFormat = "{0:c}";
        }

        return defaultFormat;
    }
}

Listing 3 – Helper extension methods 

UPDATED: 2008/11/10 altered ToTitleFromPascal extension method to remove namespace and to force to title case in cases where Table or column name is:
EntitiesModel.MyEntity
or
tbl_name_of_table

I’ve moved my helper extension methods out of the class and rewritten the ToHumanFromPascal as ToTitleFromPascal and used Regex to do my converting.

I hope Matt doesn't mind.

ASP.NET Dynamic Data Links

Some great posts by Matt Berseth

• Simple 5 Table Northwind Example: Matt Berseth kicks off his ASP.NET Dynamic Data tutorial series with a nice post that shows how to build a simple 5 table application using ASP.NET Dynamic Data with .NET 3.5 SP1.

• Dynamic Data And Custom Metadata Providers: Matt continues the series and covers the MetadataType attribute, and how you can use it to annotate your entities with additional metadata.

• Dynamic Menu for your Dynamic Data: Matt continues and covers how to add a data-driven menu to the site.

• Customizing the Delete Confirmation Dialog: Matt continues and demonstrates how to build a nice UI experience when deleting records in a dynamic data application.

• Experimenting with YUI's DataTable and DataSource Controls: Matt experiments with how to use client-side AJAX components together with dynamic data.

Dynamic Data Custom Pages: Dynamic/Templated FromView

These articles are now under the title of Custom PageTemplates:

1. Custom PageTemplates Part 1 - Custom PageTemplates with Ajax Control Toolkit Tabs
2. Custom PageTemplates Part 2 - A variation of Part 1 with the Details and SubGrid in Tabs
3. Custom PageTemplates Part 3 - Dynamic/Templated Grid with Insert (Using ListView)
4. Custom PageTemplates Part 4 - Dynamic/Templated FromView

Continuing on from Part 3 the same techniques will be applied to the FormView, making the FormView Dynamic and also having the facility to dynamically load user defined Templates at runtime.

Fugure 1 – FormViewPage in action

Note the Edit, Delete and New links these all act on this page and do not redirect to other pages.

Altering the Routing

Replace the default route Listing 1

routes.Add(new DynamicDataRoute("{table}/{action}.aspx")
{
    Constraints = new RouteValueDictionary(new { action = "List|Edit|Details|Insert" }),
    Model = model
});

Listing 1 – original routing in Global.asax

With the new routes in Listing 2

routes.Add(new DynamicDataRoute("{table}/{action}.aspx")
{
    Constraints = new RouteValueDictionary(new { action = "List" }),
    Model = model
});

routes.Add(new DynamicDataRoute("{table}/{action}/FormViewPage.aspx")
{
    Constraints = new RouteValueDictionary(new { action = "Edit|Details|Insert" }),
    ViewName = "FormViewPage",
    Model = model,
});

Listing 2 – changes to routing in global.asax

Note that the action {table}/{action}/FormViewPage.aspx as a prefix to the page name, this will be used to identify the pages mode (Edit, Delete and Insert)

The FromViewPage

<%@ Page 
    Language="C#" 
    MasterPageFile="~/Site.master" 
    CodeFile="FormViewPage.aspx.cs" 
    Inherits="FormViewPage" %>

<asp:Content 
    ID="Content1" 
    ContentPlaceHolderID="ContentPlaceHolder1" 
    Runat="Server">
    
    <asp:DynamicDataManager 
        ID="DynamicDataManager1" 
        runat="server" 
        AutoLoadForeignKeys="true" />

    <h2><%= table.DisplayName %></h2>

    <asp:ScriptManagerProxy 
        runat="server" 
        ID="ScriptManagerProxy1" />

    <asp:UpdatePanel 
        ID="UpdatePanel1" 
        runat="server">
        <ContentTemplate>

            <asp:ValidationSummary 
                ID="ValidationSummary_Edit" 
                EnableClientScript="true"
                HeaderText="List of validation errors" 
                ValidationGroup="FormView_Edit" 
                runat="server" />
                
            <asp:ValidationSummary 
                ID="ValidationSummary_Insert" 
                EnableClientScript="true"
                HeaderText="List of validation errors" 
                ValidationGroup="FormView_Insert" 
                runat="server" />
                
            <asp:DynamicValidator 
                ID="Validator_Edit" 
                Display="None" 
                ValidationGroup="FormView_Edit"
                ControlToValidate="FormView1" 
                runat="server" />
                
            <asp:DynamicValidator 
                ID="Validator_Insert" 
                Display="None" 
                ValidationGroup="FormView_Insert"
                ControlToValidate="FormView1" 
                runat="server" />
                
            <asp:FormView 
                ID="FormView1" 
                DataSourceID="FormViewDataSource" 
                OnItemDeleted="FormView_ItemDeleted"
                runat="server" onitemcommand="FormView1_ItemCommand" 
                oniteminserted="FormView1_ItemInserted">
            </asp:FormView>
            
            <asp:LinqDataSource 
                ID="FormViewDataSource" 
                AutoGenerateWhereClause="true" 
                EnableDelete="true" 
                EnableUpdate="true" 
                EnableInsert="true"
                runat="server">
                <WhereParameters>
                    <asp:DynamicQueryStringParameter />
                </WhereParameters>
            </asp:LinqDataSource>
            
            <br />
            
            <div class="bottomhyperlink">
                <asp:HyperLink 
                    ID="ListHyperLink" 
                    runat="server">Show all items</asp:HyperLink>
            </div>        
        
        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

Listing 3 – FormViewPage.aspx

using System;
using System.IO;
using System.Web.DynamicData;
using System.Web.UI.WebControls;

public partial class FormViewPage : System.Web.UI.Page
{
    protected MetaTable table;

    protected void Page_Init(object sender, EventArgs e)
    {
        DynamicDataManager1.RegisterControl(FormView1);
        table = FormViewDataSource.GetTable();

        // supported templates
        // get tamplate path
        var formViewTemplatePath = table.Model.DynamicDataFolderVirtualPath + "Templates/FormViewPage/" + table.Name + "/";

        // load user templates if they exist
        if (File.Exists(Server.MapPath(formViewTemplatePath + "ItemTemplate.ascx")))
            FormView1.ItemTemplate = LoadTemplate(formViewTemplatePath + "ItemTemplate.ascx");
        else
            FormView1.ItemTemplate = new FromViewPageRowGenerator(table, FormViewTemplateType.ItemTemplate);

        // load user templates if they exist
        if (File.Exists(Server.MapPath(formViewTemplatePath + "EditItemTemplate.ascx")))
            FormView1.EditItemTemplate = LoadTemplate(formViewTemplatePath + "EditItemTemplate.ascx");
        else
            FormView1.EditItemTemplate = new FromViewPageRowGenerator(table, FormViewTemplateType.EditItemTemplate);

        // load user templates if they exist
        if (File.Exists(Server.MapPath(formViewTemplatePath + "InsertItemTemplate.ascx")))
            FormView1.InsertItemTemplate = LoadTemplate(formViewTemplatePath + "InsertItemTemplate.ascx");
        else
            FormView1.InsertItemTemplate = new FromViewPageRowGenerator(table, FormViewTemplateType.InsertItemTemplate);

        // load user templates if they exist
        if (File.Exists(Server.MapPath(formViewTemplatePath + "EmptyDataTemplate.ascx")))
            FormView1.EmptyDataTemplate = LoadTemplate(formViewTemplatePath + "EmptyDataTemplate.ascx");
        else
            FormView1.EmptyDataTemplate = new FromViewPageRowGenerator(table, FormViewTemplateType.EmptyDataTemplate);
        //FormView1.FooterTemplate = null;
        //FormView1.HeaderTemplate = null;
        //FormView1.PagerTemplate = null;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        table = FormViewDataSource.GetTable();
        Title = table.DisplayName;

        // I don't know if this is 
        // the best way to do this
        // get the FormViews mode from the url
        String path = Request.Path.Substring(0, Request.Path.LastIndexOf("/"));
        var qs = path.Substring(path.LastIndexOf("/") + 1, path.Length - (path.LastIndexOf("/") + 1));
        switch (qs)
        {
            case "Details":
                FormView1.DefaultMode = FormViewMode.ReadOnly;
                break;
            case "Edit":
                FormView1.DefaultMode = FormViewMode.Edit;
                break;
            case "Insert":
                FormView1.DefaultMode = FormViewMode.Insert;
                break;
            default:
                break;
        }
        ListHyperLink.NavigateUrl = table.ListActionPath;
    }

    protected void FormView_ItemDeleted(object sender, FormViewDeletedEventArgs e)
    {
        if (e.Exception == null || e.ExceptionHandled)
        {
            Response.Redirect(table.ListActionPath);
        }
    }

    protected void FormView1_ItemCommand(object sender, FormViewCommandEventArgs e)
    {
        if (e.CommandName == "Cancel")
        {
            // option 1 go back to list
            //Response.Redirect(table.ListActionPath);

            // option 2 return to Normal ReadOnly
            FormView1.DefaultMode = FormViewMode.ReadOnly;
        }
    }

    protected void FormView1_ItemInserted(object sender, FormViewInsertedEventArgs e)
    {
        // option 1 go back to list
        Response.Redirect(table.ListActionPath);

        // option 2 return to Normal ReadOnly
        // note sure how to get this working at the moment
        //Response.Redirect(table.GetActionPath("Details", ???));
    }
}

Listign 4 – FormViewPage.aspx.cs

From Listings 3 and 4 you can see that this is a basic page like Details.aspx but with a FormView. The real magic goes on in the Page_Init event handler where the Templates are either loaded or dynamically generated and also in the Page_Load event handler where the default mode is detected via the URL.

Note: I’m not sure this is the best or most elegant way of doing this, but this will do for now and we will have a look at this again at a later date.

The RowGenerator

This will generate a table based FormView similar to the Details.aspx generated by the wizard (which at the time of writing was still in preview) the dynamically generated layout can be overridden be defining UserControl custom Templates in the ~/DynamicData/Templates/FormViewPage/<TableName>/<templated>.

/// <summary>
/// Template type for the FromViewPageRowGenerator 
/// </summary>
public enum FormViewTemplateType
{
    ItemTemplate,
    EditItemTemplate,
    InsertItemTemplate,
    EmptyDataTemplate,
    HeaderTemplate,
    FooterTemplate,
    PagerTemplate,
}

/// <summary>
/// Renders templates for ListView
/// </summary>
public class FromViewPageRowGenerator : ITemplate
{
    #region Member Fields, Constructor, Enums & Properties
    private MetaTable _table;
private FormViewTemplateType _type;

    public FromViewPageRowGenerator(MetaTable table, FormViewTemplateType type) 
    {
        _table = table;
        _type = type;
    }
    #endregion

    public void InstantiateIn(Control container)
    {
        IParserAccessor accessor = container;
        // get all the all scaffold columns 
        // except Long String Columns
        // SubGridViewsAttribute and column order
        var columnDetails = from c in _table.Columns
                            where c.Scaffold // && !c.IsLongString
                            select new ListViewColumn()
                            {
                                Column = c,
                                SubGridMetaData = c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault(),
                                Order = c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault() != null
                                && c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault().Order > 0
                                ? c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault().Order
                                : int.MaxValue,
                            };

        // sort according to Order first and Column Name second
        // Note: if SubGridViewsAttribute is null or the attribute
        // has no value for Order then just sort but column display name
        columnDetails = from sg in columnDetails
                        orderby sg.Order, sg.Column.DisplayName
                        select sg;

        // call the appropriate template generator
        switch (_type)
        {
            case FormViewTemplateType.ItemTemplate:
                GetItemTemplate(accessor, columnDetails, DataBoundControlMode.ReadOnly);
                break;
            case FormViewTemplateType.EditItemTemplate:
                GetItemTemplate(accessor, columnDetails, DataBoundControlMode.Edit);
                break;
            case FormViewTemplateType.InsertItemTemplate:
                GetItemTemplate(accessor, columnDetails, DataBoundControlMode.Insert);
                break;
            case FormViewTemplateType.EmptyDataTemplate:
                GetEmptyDataTemplate(accessor, columnDetails);
                break;
            case FormViewTemplateType.HeaderTemplate:
                GetHeaderTemplate(accessor, columnDetails);
                break;
            case FormViewTemplateType.FooterTemplate:
                GetFooterTemplate(accessor, columnDetails);
                break;
            case FormViewTemplateType.PagerTemplate:
                GetPagerTemplate(accessor, columnDetails);
                break;
            default:
                break;
        }
    }

    private void GetItemTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails, DataBoundControlMode templateMode)
    {
        // create new table
        var table = new HtmlTable();
        table.Attributes.Add("class", "detailstable");

        // add table to accessor
        accessor.AddParsedSubObject(table);

        // make sure there are some children columns
        if (columnDetails.Count() > 0)
        {
            // add a cell for each column in table
            foreach (ListViewColumn columnDetail in columnDetails)
            {
                // create new row for template
                var row = new HtmlTableRow();

                // add row to accessor
                table.Rows.Add(row);

                // create field name cell
                var fieldNameCell = new HtmlTableCell();
                // add cell to row
                row.Cells.Add(fieldNameCell);
                // set the title
                fieldNameCell.InnerText = columnDetail.Column.DisplayName;

                // create field cell
                var fieldCell = new HtmlTableCell();
                // add cell to row
                row.Cells.Add(fieldCell);

                // instantiate a DynamicControl for this Children Column
                var lvColumn = new DynamicControl(templateMode)
                {
                    ID = columnDetail.Column.Name,
                    ValidationGroup = "FormView_" + templateMode.ToString(),
                    // set data field to column name
                    DataField = columnDetail.Column.Name,
                };

                // add control to cell
                fieldCell.Controls.Add(lvColumn);
            }
            // create new row for template
            var commandRow = new HtmlTableRow();
            // add row to accessor
            table.Rows.Add(commandRow);

            // create the cell to hold the command buttons
            var commandCell = new HtmlTableCell();
            commandCell.Attributes.Add("class", "nowrap");
            commandCell.ColSpan = 2;
            commandRow.Cells.Add(commandCell);

            // create a spacer
            var spaceLit = new Literal();
            spaceLit.Text = @"&nbsp;";

            // create cancel link
            var cancelLink = new LinkButton()
            {
                //ID="EditLinkButton",
                Text = "Cancel",
                CausesValidation = false,
                CommandName = "Cancel",
            };

            switch (templateMode)
            {
                case DataBoundControlMode.Edit:
                    // ceate update link
                    var updateLink = new LinkButton()
                    {
                        //ID="UpdateLinkButton",
                        Text = "Update",
                        CausesValidation = true,
                        CommandName = "Update",
                    };

                    commandCell.Controls.Add(updateLink);
                    commandCell.Controls.Add(spaceLit);
                    commandCell.Controls.Add(cancelLink);
                    break;
                case DataBoundControlMode.Insert:
                    // create insert link
                    var insertLink = new LinkButton()
                    {
                        //ID="InsertLinkButton",
                        Text = "Insert",
                        CausesValidation = true,
                        CommandName = "Insert",
                    };
                    commandCell.Controls.Add(insertLink);
                    commandCell.Controls.Add(spaceLit);
                    commandCell.Controls.Add(cancelLink);
                    break;
                case DataBoundControlMode.ReadOnly:
                    // create edit link
                    var editLink = new LinkButton()
                        {
                            //ID="EditLinkButton",
                            Text = "Edit",
                            CausesValidation = false,
                            CommandName = "Edit",
                        };
                    // create delete link
                    var deleteLink = new LinkButton()
                        {
                            //ID="DeleteLinkButton",
                            Text = "Delete",
                            CommandName = "Delete",
                            CausesValidation = false,
                            OnClientClick = "return confirm(\"Are you sure you want to delete this item?\");",
                        };
                    // create new link
                    var newLink = new LinkButton()
                        {
                            //ID="insertLinkButton",
                            Text = "New",
                            CausesValidation = false,
                            CommandName = "New",
                        };

                    commandCell.Controls.Add(editLink);
                    commandCell.Controls.Add(spaceLit);
                    commandCell.Controls.Add(deleteLink);
                    commandCell.Controls.Add(spaceLit);
                    commandCell.Controls.Add(newLink);
                    break;
                default:
                    break;
            }

        }
        // if there are no children columns don't
        // bother to set the accessor to anything
    }

    private void GetEmptyDataTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails)
    {
        // create a spacer
        var literal = new Literal();
        literal.Text = @"There are currently no items in this table.";

        // add row to accessor
        accessor.AddParsedSubObject(literal);
    }

    private void GetPagerTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails)
    {
        throw new NotImplementedException();
    }

    private void GetFooterTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails)
    {
        throw new NotImplementedException();
    }

    private void GetHeaderTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails)
    {
        throw new NotImplementedException();
    }

    private class ListViewColumn
    {
        /// <summary>
        /// Column to display
        /// </summary>
        public MetaColumn Column { get; set; }

        /// <summary>
        /// MetaData if any from the original column
        /// </summary>
        public SubGridViewsAttribute SubGridMetaData { get; set; }

        /// <summary>
        /// Holds the sort order value
        /// </summary>
        public int Order { get; set; }
    }
}

Listing 5  - FromViewPageRowGenerator

The main difference between this implementation of ITemplate and the implementation in Part 3 is that the column title is in the same row as the DynamicControl so it produces a template similar to the output shown in Listing 6. The only difference between the different template types that are implemented are the links shown (Edit, Delete & New for ReadOnly), (Update & Cancel for Edit) and (Insert & Cancel for Insert) and the mode of the DynamicControls.

<table class="detailstable">
    <tr>
        <th>
            OrderDate
        </th>
        <td>
            <asp:DynamicControl 
                ID="DynamicControl1" 
                DataField="OrderDate" 
                Mode="ReadOnly" 
                runat="server" />
        </td>
    </tr>
    <tr>
        <th>
            RequiredDate
        </th>
        <td>
            <asp:DynamicControl 
                ID="DynamicControl2" 
                DataField="RequiredDate" 
                Mode="ReadOnly" 
                runat="server" />
        </td>
    </tr>
    ...// shortened for brevity 

    <tr>
        <td colspan="2">
            <asp:LinkButton ID="EditLinkButton" CausesValidation="false" CommandName="Edit" runat="server"> Edit </asp:LinkButton>
            <asp:LinkButton ID="DeleteLinkButton" CausesValidation="false" CommandName="Delete"
                OnClientClick='return confirm("Are you sure you want to delete this item?");'
                runat="server"> Delete </asp:LinkButton>
            <asp:LinkButton ID="InsertLinkButton" CausesValidation="false" CommandName="New" runat="server"> New </asp:LinkButton>
        </td>
    </tr>
</table>

Listing 6 – Fragment of the output from FormViewTemplateType

Project Download

Again V3 contains all from the previous parts 1 - 3

Dynamic Data Custom Pages: Dynamic/Templated Grid with Insert (Using ListView)

These articles are now under the title of Custom PageTemplates:

1. Custom PageTemplates Part 1 - Custom PageTemplates with Ajax Control Toolkit Tabs
2. Custom PageTemplates Part 2 - A variation of Part 1 with the Details and SubGrid in Tabs
3. Custom PageTemplates Part 3 - Dynamic/Templated Grid with Insert (Using ListView)
4. Custom PageTemplates Part 4 - Dynamic/Templated FromView

What are we trying to achieve here, let me start with an screen shot. Apparently a GridView with Insert, well actually its a ListView and not a big deal we can already do ListViews with Dynamic Data. Well this is a Dynamic ListView not a new control but a ListView with dynamically generated columns (templates actually). So what I wanted to achieve here was all the flexibility of the ListView with the dynamicness (I know not a real word) of the GridView under Dynamic Data.

Figure 1 – Apparently a GridView with Insert

Steps to build this Custom PageTemplate

1. Using a Custom Page generated by the Wizard as a basis for the Custom PageTemplate
2. How to build a Column Generator Class for the ListView
3. Adding the facility to Load Custom Templates at Runtime

Using a Custom Page generated by the Wizard as a basis for the Custom PageTemplate

I’m not going to do a step by step cut and paste of how to take a page generated by the Wizard and making it into a custom PageTemplate. What I am going to do is just show you the aspx page.

<%@ Page 
    Language="C#" 
    MasterPageFile="~/Site.master" 
    CodeFile="ListViewPage.aspx.cs" 
    Inherits="ListViewPage" %>

<%@ Register 
    Src="~/DynamicData/Content/ListViewPager.ascx" 
    TagName="ListViewPager"
    TagPrefix="asp" %>
    
<%@ Register 
    Src="~/DynamicData/Content/DynamicLinkControl.ascx" 
    TagName="DynamicLink"
    TagPrefix="asp" %>
    
<%@ Register 
    src="~/DynamicData/Content/FilterUserControl.ascx" 
    tagname="DynamicFilter" 
    tagprefix="asp" %>

<asp:Content 
    ID="Content1" 
    ContentPlaceHolderID="ContentPlaceHolder1" 
    Runat="Server">
    
    <asp:DynamicDataManager 
        ID="DynamicDataManager1" 
        runat="server" 
        AutoLoadForeignKeys="true" />

    <h2><%= table.DisplayName%></h2>

    <asp:ScriptManagerProxy 
        runat="server" 
        ID="ScriptManagerProxy1" />

    <asp:UpdatePanel 
        ID="UpdatePanel1" 
        runat="server">
        <ContentTemplate>
        
            <asp:ValidationSummary 
                ID="ValidationSummary_Edit" 
                EnableClientScript="true"
                HeaderText="List of validation errors" 
                ValidationGroup="ListView_Edit" 
                runat="server" />
                
            <asp:ValidationSummary 
                ID="ValidationSummary_Insert" 
                EnableClientScript="true"
                HeaderText="List of validation errors" 
                ValidationGroup="ListView_Insert" 
                runat="server" />
                
            <asp:DynamicValidator 
                ID="Validator_Edit" 
                Display="None" 
                ValidationGroup="ListView_Edit"
                ControlToValidate="ListView1" 
                runat="server" />
                
            <asp:DynamicValidator 
                ID="Validator_Insert" 
                Display="None" 
                ValidationGroup="ListView_Insert"
                ControlToValidate="ListView1" 
                runat="server" />

            <asp:FilterRepeater 
                ID="FilterRepeater" 
                runat="server">
                <ItemTemplate>
                    <asp:Label 
                        runat="server" 
                        Text='<%# Eval("DisplayName") %>' 
                        AssociatedControlID="DynamicFilter$DropDownList1" />
                    <asp:DynamicFilter 
                        runat="server" 
                        ID="DynamicFilter" 
                        OnSelectedIndexChanged="OnFilterSelectedIndexChanged" />
                </ItemTemplate>
                <FooterTemplate>
                    <br />
                    <br />
                </FooterTemplate>
            </asp:FilterRepeater>

            <asp:ListView 
                ID="ListView1" 
                DataSourceID="ListViewDataSource" 
                runat="server">
            </asp:ListView>
            
            <asp:LinqDataSource 
                ID="ListViewDataSource" 
                runat="server" 
                EnableDelete="true">
                <WhereParameters>
                    <asp:DynamicControlParameter ControlID="FilterRepeater" />
                </WhereParameters>
            </asp:LinqDataSource>

        </ContentTemplate>
    </asp:UpdatePanel>
</asp:Content>

Listing 1 – ListviewPage.aspx PageTemplate

As you can see (if you’ve ever created a custom page with the wizard) I’ve removed all the templates from the ListView and renamed all the ID’s appropriately (the existing naming would have worked but I like everything to be tidy).

The second thing to notice is that there are two ValidationSummarys and two DynamicValidators and from their naming you should be able to tell that one set is for editing and the other for inserting. This is to resolve the conflict Update and Insert buttons on validation (this is generated by the wizard).

Next I’ve removed all the table and context specific settings from the LinqDataSource and so the page is about ready.

How to build a Column Generator Class for the ListView

There is no ColumnGenerator or RowGenerators methods on the ListView class, this is because it is a templated control. After a little research I found the ITemplate interface (which I’d used in my earlier examples) here the MSDN article I used to develop this Creating Web Server Control Templates Programmatically.

The templates that the ListView will accepts are:

• LayoutTemplate
• ItemTemplate
• EditItemTemplate
• InsertItemTemplate
• EmptyDataTemplate
• AlternatingItemTemplate
• EmptyItemTemplate
• GroupSeparatorTemplate
• GroupTemplate
• ItemSeparatorTemplate
• SelectedItemTemplate

So of the above Templates which do we need to implement to get a column generator working?

• LayoutTemplate the layout
• ItemTemplate each row
• EditItemTemplate the edit row
• InsertItemTemplate the insert row
• EmptyDataTemplate only required if you set the InsertItemPosition to none

These are the Templates that are required to be implement the column generator.

Next creating the column generator using the ITemplate interface. The ITemplate interface requires only one method to be implemented:

public void InstantiateIn(Control container)

We could create a ITemplate interface class for each Template we need but what I decided to do was to create on class that would do all the Templates requires for the ListView, Listing 2 contain the InstantiateIn method.

public void InstantiateIn(Control container)
{
    IParserAccessor accessor = container;
    // get all the all scaffold columns 
    // except Long String Columns
    // SubGridViewsAttribute and column order
    var columnDetails = from c in _table.Columns
                        where c.Scaffold && !c.IsLongString
                        select new ListViewColumn()
                        {
                            Column = c,
                            SubGridMetaData = c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault(),
                            Order = c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault() != null
                            && c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault().Order > 0
                            ? c.Attributes.OfType<SubGridViewsAttribute>().FirstOrDefault().Order
                            : int.MaxValue,
                        };

    // sort according to Order first and column name second
    // note if SubGridViewsAttribute is null or the attribute
    // has no value for Order then just sort but column display name
    columnDetails = from sg in columnDetails
                    orderby sg.Order, sg.Column.DisplayName
                    select sg;

    // call the appropriate template generator
    switch (_type)
    {
        case TemplateType.LayoutTemplate:
            GetLayoutTemplate(accessor, columnDetails);
            break;
        case TemplateType.ItemTemplate:
            GetItemTemplate(accessor, columnDetails, TemplateMode.Normal);
            break;
        case TemplateType.AlternatingItemTemplate:
            GetItemTemplate(accessor, columnDetails, TemplateMode.Alternate);
            break;
        case TemplateType.EditItemTemplate:
            GetItemTemplate(accessor, columnDetails, TemplateMode.Edit);
            break;
        case TemplateType.InsertItemTemplate:
            GetItemTemplate(accessor, columnDetails, TemplateMode.Insert);
            break;
        case TemplateType.SelectedItemTemplate:
            GetItemTemplate(accessor, columnDetails, TemplateMode.Selected);
            break;
        case TemplateType.GroupTemplate:
            GetGroupTemplate(accessor, columnDetails);
            break;
        case TemplateType.GroupSeparatorTemplate:
            GetGroupSeparatorTemplate(accessor, columnDetails);
            break;
        case TemplateType.ItemSeparatorTemplate:
            GetItemSeparatorTemplate(accessor, columnDetails);
            break;
        case TemplateType.EmptyDataTemplate:
            GetEmptyDataTemplate(accessor, columnDetails);
            break;
        case TemplateType.EmptyItemTemplate:
            GetEmptyItemTemplate(accessor, columnDetails);
            break;
        default:
            break;
    }
}

Listing 2 – InstantiateIn method

Yes I know I’ve implemented the InstantiateIn method to cover all the Template types, but I thought if the scaffolding is there for the other Templates then it would be a simple matted to implement them if needed at a later date.

So now the individual Template generators are left to be built.

private void GetLayoutTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails)
{
    // make sure there are some children columns
    if (columnDetails.Count() > 0)
    {
        // HtmlTable/HtmlTableRow/HtmlTableCell 
        // create table
        var htmlTable = new HtmlTable();
        htmlTable.Attributes.Add("class", "listview");

        // add table to accessor
        accessor.AddParsedSubObject(htmlTable);

        // create header row
        var headerRow = new HtmlTableRow();

        // create empty header cell
        // NOTE: you could move the command cell to after the
        //       foreach column generator code if you wanted
        //       the command buttons to be at the end of the row
        var commandCell = new HtmlTableCell("th");
        headerRow.Cells.Add(commandCell);

        // add a column heading for each column
        foreach (ListViewColumn columnDetail in columnDetails)
        {
            //<asp:LinkButton 
            //    ID="OrderDateLinkButton" 
            //    CommandName="Sort" 
            //    CommandArgument="OrderDate"
            //runat="server"> OrderDate </asp:LinkButton>

            var cell = new HtmlTableCell("th");
            var linkButton = new LinkButton()
            {
                ID = columnDetail.Column.Name + "LinkButton",
                CommandName = "Sort",
                CommandArgument = columnDetail.Column.Name,
                Text = columnDetail.Column.DisplayName,
            };
            cell.Controls.Add(linkButton);
            headerRow.Cells.Add(cell);
        }
        htmlTable.Rows.Add(headerRow);

        //<tbody>
        //    <tr id="itemPlaceHolder" runat="server">
        //    </tr>
        //</tbody>
        // create the table body and item place holder
        var itemPlaceholder = new HtmlTableRow();
        itemPlaceholder.ID = "itemPlaceholder";
        itemPlaceholder.Attributes.Add("runat", "Server");
        htmlTable.Rows.Add(itemPlaceholder);

        //<tfoot>
        //    <tr class="footer">
        //        <td colspan="14">
        //            <asp:ListViewPager ID="ListViewDataPager" runat="server"></asp:ListViewPager>
        //        </td>
        //    </tr>
        //</tfoot>
        // create the footer
        var footerRow = new HtmlTableRow();
        footerRow.Attributes.Add("class", "footer");

        // set column span to number od columns
        // plus 1 to account for the command column
        var footerCell = new HtmlTableCell();

        // get column span
        int columnSpan = columnDetails.Count() + 1;
        footerCell.Attributes.Add("colspan", columnSpan.ToString());

        // get the path to the ListViewPager
        var listViewPagerPath = _table.Model.DynamicDataFolderVirtualPath + "Content/ListViewPager.ascx";
        // load ListViewPager control
        var listViewPager = _page.LoadControl(listViewPagerPath);
        listViewPager.ID = "ListViewDataPager";
        footerCell.Controls.Add(listViewPager);
        footerRow.Cells.Add(footerCell);
        htmlTable.Rows.Add(footerRow);

    }
    // if there are no children columns don't
    // bother to set the accessor to anything
}

Listing 3 - GetLayoutTemplate

In Listing 3 the GetLayoutTemplate generates a template the same as the declarative template in the wizard generated page:

• Column headers with sort links
• Item Place Holder
• Footer with the ListViewPager (which needs copying from a wizard generated website)

Note: It’s worth pointing out that the command column is added to the header in the standard left position you could move it to the right by moving it to after the foreach loop.

private void GetItemTemplate(IParserAccessor accessor, IEnumerable<ListViewColumn> columnDetails, TemplateMode templateMode)
{
    // make sure there are some children columns
    if (columnDetails.Count() > 0)
    {
        // set the dynamic control mode to read only
        DataBoundControlMode mode = DataBoundControlMode.ReadOnly;
        String validationGroup;

        // create a spacer
        var litSpacer = new Literal();
        litSpacer.Text = @"&nbsp;";

        // create new row for template
        var row = new HtmlTableRow();

        // add row to accessor
        accessor.AddParsedSubObject(row);

        // create the cell to hold the command buttons
        // NOTE: you could move the command cell to after the
        //       foreach column generator code if you wanted
        //       the command buttons to be at the end of the row
        //       you would also need to modify the LayoutTemplate code
        var commandCell = new HtmlTableCell();
        commandCell.Attributes.Add("class", "nowrap");
        row.Cells.Add(commandCell);

        // set appropriate variable depending
        // on what mode the row is to be in
        switch (templateMode)
        {
            case TemplateMode.Edit:
                mode = DataBoundControlMode.Edit;
                validationGroup = "ListView_Edit";

                //Update Link
                //<asp:LinkButton 
                //    ID="UpdateLinkButton" 
                //    ValidationGroup="ListView_Edit" 
                //    CommandName="Update"
                //runat="server"> Update </asp:LinkButton>
                var lbUpdate = new LinkButton()
                    {
                        //ID = "UpdateLinkButton",
                        CommandName = "Update",
                        Text = "Update",
                        ValidationGroup = validationGroup,
                    };
                commandCell.Controls.Add(lbUpdate);
                commandCell.Controls.Add(litSpacer);

                //Cancel Link
                //<asp:LinkButton 
                //    ID="CancelLinkButton" 
                //    CausesValidation="false" 
                //    CommandName="Cancel"
                //    runat="server"> Cancel </asp:LinkButton>
                var lbCancel = new LinkButton()
                {
                    //ID = "UpdateLinkButton",
                    CommandName = "Cancel",
                    Text = "Cancel",
                };
                commandCell.Controls.Add(lbCancel);
                break;
            case TemplateMode.Insert:
                mode = DataBoundControlMode.Insert;
                validationGroup = "ListView_Insert";

                //Insert Link
                //<asp:LinkButton 
                //    ID="InsertLinkButton" 
                //    ValidationGroup="ListView_Insert" 
                //    CommandName="Insert"
                //    runat="server"> Insert </asp:LinkButton>
                var lkbInsert = new LinkButton()
                {
                    //ID = "InsertLinkButton",
                    CommandName = "Insert",
                    Text = "Insert",
                    ValidationGroup = validationGroup,
                };
                commandCell.Controls.Add(lkbInsert);
                commandCell.Controls.Add(litSpacer);

                //Cancel Link
                //<asp:LinkButton 
                //    ID="CancelLinkButton" 
                //    CausesValidation="false" 
                //    CommandName="Cancel"
                //    runat="server"> Cancel </asp:LinkButton>
                var lkbCancel = new LinkButton()
                {
                    //ID = "CancelLinkButton",
                    CommandName = "Cancel",
                    Text = "Cancel",
                    CausesValidation = false,
                };
                commandCell.Controls.Add(lkbCancel);
                break;
            case TemplateMode.Selected:
                row.Attributes.Add("class", "selected");
                goto case TemplateMode.Normal;
            case TemplateMode.Alternate:
                row.Attributes.Add("class", "alternate");
                goto case TemplateMode.Normal;
            case TemplateMode.Normal:
                validationGroup = "";

                //Edit Link
                //<asp:LinkButton 
                //    ID="EditLinkButton" 
                //    CausesValidation="false" 
                //    CommandName="Edit" 
                //    runat="server"> Edit </asp:LinkButton>
                var lkbEdit = new LinkButton()
                {
                    //ID = "EditLinkButton",
                    CommandName = "Edit",
                    Text = "Edit",
                    CausesValidation = false,
                };
                commandCell.Controls.Add(lkbEdit);
                commandCell.Controls.Add(litSpacer);

                //Delete Link
                //<asp:LinkButton 
                //    ID="DeleteLinkButton" 
                //    CausesValidation="false" 
                //    CommandName="Delete"
                //    OnClientClick='return confirm("Are you sure you want to delete this item?");'
                //    runat="server"> Delete </asp:LinkButton>
                var lkbDelete = new LinkButton()
                {
                    //ID = "DeleteLinkButton",
                    CommandName = "Delete",
                    Text = "Delete",
                    CausesValidation = false,
                    OnClientClick = "return confirm(\"Are you sure you want to delete this item?\");",
                };
                commandCell.Controls.Add(lkbDelete);
                commandCell.Controls.Add(litSpacer);

                //Details Link - redirects to the details page
                //<asp:DynamicLink 
                //    ContextTypeName="NWDataContext" 
                //    TableName="Orders" 
                //    Action="Details"
                //    Text="Details"
                //    runat="server" />
                var listViewPagerPath = _table.Model.DynamicDataFolderVirtualPath + "Content/DynamicLinkControl.ascx";

                // NOTE: Need to cast 
                //       DynamicLinkControl.ascx to DynamicLinkControlInterface
                //       which is just a dummy class allowing access to the
                //       DynamicLinkControl's properties
                var dlcDetails = (DynamicLinkControlInterface)_page.LoadControl(listViewPagerPath);
                dlcDetails.ID = "DetailsLinkButton";
                dlcDetails.ContextTypeName = _table.DataContextType.Name;
                dlcDetails.TableName = _table.Name;
                dlcDetails.Action = "Details";
                dlcDetails.Text = "Details";

                commandCell.Controls.Add(dlcDetails);
                break;
            default:
                validationGroup = "";
                break;
        }

        // add a cell for each column in table
        foreach (ListViewColumn columnDetail in columnDetails)
        {
            // create new cell
            var cell = new HtmlTableCell();

            // add cell to row
            row.Cells.Add(cell);

            // instantiate a DynamicControl for this Children Column
            var lvColumn = new DynamicControl(mode)
            {
                ID = columnDetail.Column.Name,
                ValidationGroup = validationGroup,
                // set data field to column name
                DataField = columnDetail.Column.Name,
            };

            // add control to cell
            cell.Controls.Add(lvColumn);
        }
    }
    // if there are no children columns don't
    // bother to set the accessor to anything
}

Listing 4 – GetItemTemplate

The GetItemTemplate handles the following templates Normal, Edit, Insert and Alternate and Selected.

Note: It’s worth pointing out that the command column is added to the header in the standard left position you could move it to the right by moving it to after the foreach loop.

The code in Listing 4 can be broken down into two sections the switch statement and the foreach loop.

The switch statement is used mainly to determine which command links to add to the command column/cell. The foreach loop is used to create the columns.

var dlcDetails = (DynamicLinkControlInterface)_page.LoadControl(listViewPagerPath);
dlcDetails.ID = "DetailsLinkButton";
dlcDetails.ContextTypeName = _table.DataContextType.Name;
dlcDetails.TableName = _table.Name;
dlcDetails.Action = "Details";
dlcDetails.Text = "Details";

See the above line of code where we cast the ListViewPager as a DynamicLinkControlInterface; here we needed to create a class that implements the properties of the DynamicLinkControl to allow us to set properties when the UserControl is loaded.

/// <summary>
/// This class is used like an interface
/// so that when the DynamicLinkControl control
/// is loaded it can be case as DynamicLinkControlInterface
/// to gain access to its properties
/// </summary>
public class DynamicLinkControlInterface : System.Web.UI.UserControl

Listing 5- DynamicLinkControlInterface class

/// <summary>
///  NOTE: Need to change 
///        System.Web.UI.UserControl to DynamicLinkControlInterface
///        which is just a dummy class allowing access to the
///        DynamicLinkControl's properties in ListViewColumnGenerator
/// </summary>
public partial class DynamicLinkControl : DynamicLinkControlInterface

Listing 6 - Modified DynamicLinkControl

Here you can see in Listing 5 and 6 the DynamicLinkControlInterface inherits UserControl and then DynamicLinkControl inherits DynamicLinkControlInterface thus allowing us to cast the DynamicLinkControl as DynamicLinkControlInterface allowing it’s properties to be set as runtime.

That’s the bones of the implementation.

Adding the facility to Load Custom Templates at Runtime

This was the simplest and hardest to get working:

protected void Page_Init(object sender, EventArgs e)
{
    DynamicDataManager1.RegisterControl(ListView1, true /*setSelectionFromUrl*/);

    // must get table before loading templates
    table = ListViewDataSource.GetTable();

    ListViewDataSource.EnableDelete = true;
    ListViewDataSource.EnableInsert = true;
    ListViewDataSource.EnableUpdate = true;

    // get tamplate path
    var listViewTemplatePath = table.Model.DynamicDataFolderVirtualPath + "Templates/ListView/" + table.Name + "/";

    // load layout template
    if (File.Exists(Server.MapPath(listViewTemplatePath + "LayoutTemplate.ascx")))
    {
        // set Item Placeholder ID
        ListView1.ItemPlaceholderID = layoutContainerId + "$" + itemPlaceHolderId;

        // add event handler to handle the loaded user control
        ListView1.LayoutTemplate = LoadTemplate(listViewTemplatePath + "LayoutTemplate.ascx");
    }
    else
        ListView1.LayoutTemplate = new ListViewColumnGenerator(table, Page, TemplateType.LayoutTemplate);

    // load item template
    if (File.Exists(Server.MapPath(listViewTemplatePath + "ItemTemplate.ascx")))
        ListView1.ItemTemplate = Page.LoadTemplate(listViewTemplatePath + "ItemTemplate.ascx");
    else
        ListView1.ItemTemplate = new ListViewColumnGenerator(table, Page, TemplateType.ItemTemplate);

    // load edit template
    if (File.Exists(Server.MapPath(listViewTemplatePath + "EditItemTemplate.ascx")))
        ListView1.EditItemTemplate = Page.LoadTemplate(listViewTemplatePath + "EditItemTemplate.ascx");
    else
        ListView1.EditItemTemplate = new ListViewColumnGenerator(table, Page, TemplateType.EditItemTemplate);

    // load insert template
    if (File.Exists(Server.MapPath(listViewTemplatePath + "InsertItemTemplate.ascx")))
        ListView1.InsertItemTemplate = Page.LoadTemplate(listViewTemplatePath + "InsertItemTemplate.ascx");
    else
        ListView1.InsertItemTemplate = new ListViewColumnGenerator(table, Page, TemplateType.InsertItemTemplate);

    // set the location of the insert row
    ListView1.InsertItemPosition = InsertItemPosition.LastItem;

    // load empty template
    ListView1.EmptyDataTemplate = new ListViewColumnGenerator(table, Page, TemplateType.EmptyDataTemplate);
}

Listing 7 – ListViewPages.aspx Page_Init

Listing 7 simply checks to see if a template exists in the ~/DynmaicData/Templates/FormView/<table> folder for the appropriate template and loads it, if not there it dynamically creates the template.

Note: If you create a custom template for the ListViewPage.aspx then you MUST create a template for all (Layout, Item, Edit and Insert) Templates.

Waht mde it the hardest was the one caveat that got me, which was the fact that a Template loaded from a UserControl, was that the UserControl becomes a NamingContainer, (this affects only the LayoutTemplate) you can find a workaround here on Mike Ormond's blog. However I found a more elegant way, all you need to do is set the UserControl’s ID in the Page_Init of the UserControl (see Listing 8) and then you can set the ListView1.ItemPlaceholderID to the UserControl ID plus the item placeholder ID (see Listing 9).

public partial class LayoutTemplate : System.Web.UI.UserControl
{
    protected void Page_Init(object sender, EventArgs e)
    {
        this.ID = "layoutTemplate";
    }
}

Listing 8 - LayoutTemplate code behind

// set Item Placeholder ID
ListView1.ItemPlaceholderID = "layoutTemplate$itemPlaceHolder";

Listing 9 – Excerpt from the Page_Init of the ListViewPage.aspx.cd page

In Listings 8 and 9 you can see that you can be certain of the NamingContainers ID and therefore set it with out messing about in code after loading the LayoutTemplate.

Project Download

The full project including the previous two articles in this series.