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:

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

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.

Figure 2  - Model route

 

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:

Figure 2 – Both Models shown

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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

And here’s the download