Sunday 7 December 2008

Dynamic Data – Registering Multiple Models

There are two way to get multiple model into your site:

  1. Register Multiple DataContexts with the default Model.
  2. Register each DataContext with it’s own Model.

My Models:

ScreenShot149

Register Multiple DataContexts with the default Model.

This is the simplest approach you have multiple EDMX or DBML files, all you need to do is lines like so in the Global.ascx file:

model.RegisterContext(typeof(Table1DataContext), 
    new ContextConfiguration() { ScaffoldAllTables = true });
model.RegisterContext(typeof(Table2DataContext), 
    new ContextConfiguration() { ScaffoldAllTables = true });

Listing 1 – Adding a Context to the Model

Note: you are adding the DataContext/ObjectContext to the existing model

ScreenShot148

Figure 1 – Both Contexts in one model.

Register each DataContext with it’s own Model.

This is slightly more work, you are basically duplicating each line of code for one model to two.

public static void RegisterRoutes(RouteCollection routes)
{
    // Model1 ======================================================
    MetaModel model = new MetaModel();

    model.RegisterContext(typeof(Table1DataContext),
         new ContextConfiguration() { ScaffoldAllTables = true });

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

    // Model2 ======================================================
    MetaModel model1 = new MetaModel();

    model1.RegisterContext(typeof(Table2DataContext),
        new ContextConfiguration() { ScaffoldAllTables = true });

    routes.Add(new DynamicDataRoute("Model1/{table}/{action}.aspx")
    {
        Constraints = new RouteValueDictionary(new { action = "List|Details|Edit|Insert" }),
        Model = model1
    });
}

Listing 2 – Creating multiple models

Note: See the DynamicDataRoute("Model1/{table}/{action}.aspx") it is important that you differentiate the route in some way especially if some of the tables are the same name.

ScreenShot150

Figure 2  - Model route

 ScreenShot151

Figure 3  - Model1 route

As you can see from Figures 1 & 2 just by adding a differentiating route you can guarantee that there will be no table name conflicts between you models.

That get your Models registered now how to access them:

<h2>My first set of tables</h2>

<br /><br />

<asp:GridView ID="Menu1" runat="server" AutoGenerateColumns="false"
    CssClass="gridview" AlternatingRowStyle-CssClass="even">
    <Columns>
        <asp:TemplateField HeaderText="Table Name" SortExpression="TableName">
            <ItemTemplate>
                <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%#Eval("ListActionPath") %>'><%#Eval("DisplayName") %></asp:HyperLink>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>
<br /><br />

<h2>My Second set of tables</h2>

<br /><br />

<asp:GridView ID="Menu2" runat="server" AutoGenerateColumns="false"
    CssClass="gridview" AlternatingRowStyle-CssClass="even">
    <Columns>
        <asp:TemplateField HeaderText="Table Name" SortExpression="TableName">
            <ItemTemplate>
                <asp:HyperLink ID="HyperLink1" runat="server" NavigateUrl='<%#Eval("ListActionPath") %>'><%#Eval("DisplayName") %></asp:HyperLink>
            </ItemTemplate>
        </asp:TemplateField>
    </Columns>
</asp:GridView>

Listing 3 – Add a second Menu to the Default.aspx

protected void Page_Load(object sender, EventArgs e)
{
    // Model 1
    System.Collections.IList visibleTables = 
MetaModel.Default.VisibleTables;
if (visibleTables.Count == 0) { throw new InvalidOperationException("There are no accessible tables."); } Menu1.DataSource = visibleTables; Menu1.DataBind(); // Model 2 System.Collections.IList visibleTables2 =
MetaModel.GetModel(typeof(Table2DataContext)).VisibleTables;
if (visibleTables.Count == 0) { throw new InvalidOperationException("There are no accessible tables."); } Menu2.DataSource = visibleTables2; Menu2.DataBind(); }

Listing 4 – Default.aspx.cs code behind

Model 1 is normal but Model 2 you are required to get the model using GetModel(typeof(DataContextName)) so what you should now see when you run the site is:

ScreenShot147

Figure 2 – Both Models shown


I know this is simple stuff and I know I have answered questions be for butI found I hadn’t an article on my blog smile_teeth

And here’s the download

Tuesday 2 December 2008

Dynamic Data - Updated URL FieldTemplate

Sorry I’ve been quiet for such a long time but towards the end of October I was helping out with a local charity and in early November I started some Freelance Web Development in DD, so from now on the posts will still come but will be a bit more infrequent (except when there is some new stuff to get our teeth into)

So improving the Url FieldTemplate, here’s what you see if you use the URL FieldTemplate as is from DD Futures:

ScreenShot004

Figure 1 – Standard Url FieldTemplate

And here’s what I want to see

ScreenShot142

Figure 2 – Improved Url FieldTemplate

Here’s the code:

<%@ Control 
    Language="C#" 
    CodeFile="Url.ascx.cs" 
    Inherits="Url" %>

<asp:HyperLink 
    ID="HyperLinkUrl" 
    runat="server" 
    Target="_blank" />

Listing 1 – Url.ascx file

public partial class Url : System.Web.DynamicData.FieldTemplateUserControl
{
    protected override void OnDataBinding(EventArgs e)
    {
        string url = FieldValueString;
        if (!(url.StartsWith("http://", StringComparison.OrdinalIgnoreCase) || 
url.StartsWith("https://", StringComparison.OrdinalIgnoreCase))) { url = "http://" + url; } HyperLinkUrl.NavigateUrl = url; // set display text of the url HyperLinkUrl.Text = String.IsNullOrEmpty(Column.GetUrl())?
FieldValueString : Column.GetUrl(); } public override Control DataControl { get { return HyperLinkUrl; } } }

Listing 2 – Url.ascx.cs file

public class UrlAttribute : Attribute
{
    public String Text { get; private set; }

    public UrlAttribute(string text)
    {
        Text = text;
    }
    public static UrlAttribute Default = new UrlAttribute(String.Empty);
}

public static partial class HelperExtansionMethods
{
    public static String GetUrl(this MetaColumn column)
    {
        return column.Attributes.OfType<UrlAttribute>().DefaultIfEmpty(UrlAttribute.Default).First().Text;
    }
}

Listing 3 – UrlAttribute and Helper method.

[Url("Insert New Products")]
public Object InsertProducts

Listing 4 – Sample use of attributes

Now if there’s no UrlAttribute then you get the standard format but when there is a UrlAttribute present then you get the display text of  the HyperLink as that of the UrlAttribute.

I though in a future article I could assign the display text of the Url FieldTemplate to another field thus making it a bit more dynamic, but that’s for another time.

Wednesday 26 November 2008

DynamicData - Automatic Column Update For Entity Framework

Update to DynamicData - Automatic Column Update

See also the MSDN referance here:

How to: Execute Business Logic During Property Changes (Entity Framework)
How to: Execute Business Logic When Saving Changes (Entity Framework)
How to: Change Relationships Between Objects (Entity Framework)

namespace NorthwindModel
{

    public partial class NorthwindEntities
    {
        partial void OnContextCreated()
        {
            this.SavingChanges += new EventHandler(OnSavingChanges);
        }

        private static void OnSavingChanges(object sender, EventArgs e)
        {

            // This will populate the PasswordHash and PasswordSalt fields
            var stateManager = ((NorthwindEntities)sender).ObjectStateManager;
            var insertedEntities = stateManager.GetObjectStateEntries(EntityState.Added);

            foreach (ObjectStateEntry stateEntryEntity in insertedEntities)
            {
                if (stateEntryEntity.Entity is Customers)
                {
                    Customers cust = (Customers)stateEntryEntity.Entity;
                    cust.CreatedBy = HttpContext.Current.User.Identity.Name;
                    cust.CreatedOn = DateTime.Now;
                    cust.UpdatedBy = HttpContext.Current.User.Identity.Name; 
                    cust.UpdatedOn = DateTime.Now;
                }
            }

            var modifiedEntities = stateManager.GetObjectStateEntries(EntityState.Modified);
            foreach (ObjectStateEntry stateEntryEntity in modifiedEntities)
            {
                if (stateEntryEntity.Entity is Customers)
                {
                    Customers cust = (Customers)stateEntryEntity.Entity;
                    cust.UpdatedBy = HttpContext.Current.User.Identity.Name; 
                    cust.UpdatedOn = DateTime.Now;
                }
            }
        }
    }
}

In the above code the CreatedBy, CreatedOn, UpdateBy and UpdatedOn properties are automatically updated every time a record is modified or UpdateBy and UpdatedOn are modified when a record is updated.

Originally posted on ASP.Net Forum by Rick Anderson here Re: Setting a scaffolded column value

Friday 24 October 2008

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

Limited Tables list from Northwind

Figure 1 - Limited Tables list from Northwind

See how the Products column has a foreign key link

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

Note that the Category column has no 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.

Download Project

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

Monday 20 October 2008

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 smile_sad 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.

Download Project

Hope this helps smile_teeth

Steve

Sunday 12 October 2008

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. smile_teeth

Friday 10 October 2008

ASP.NET Dynamic Data Links

Some great posts by Matt Berseth

Wednesday 8 October 2008

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.

FormViewPage in action

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