Access to MVC Models from standard ASCX UserControl - asp.net

I've got a simple ASCX user control (non-MVC). The user control has a property on it (let's call it Title or something).
I've also got an MVC Partial View which contains the user control.
<%# Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<SomeModel>" %>
<%# Register TagPrefix="tag" TagName="Control" Src="~/path/to/ascx/control.ascx" %>
... snip ...
<tag:Control ID="myControl" runat="server" />
What I'd like to be able to do is something like this:
<tag:Control ID="myControl" runat="server" Title="<%= Model.Title %>" />
... so that I can access some property of the model inside my Control.
Unfortunately this method doesn't work, as I get a message saying "This is not scriptlet. Will be output as plain text".
Is what I'm trying to do even possible? If so, does anyone have any ideas how I can try and do it?
If it's relevant, this is a .Net 4 project, with MVC 2 components.
Thanks!
Neil

Is what I'm trying to do even possible?
Yes but it would be extremely ugly and it involves using a code behind (in an ASP.NET MVC view!!!):
<%# Page
Language="C#"
MasterPageFile="~/Views/Shared/Site.Master"
Inherits="AppName.Views.Home.Index"
CodeBehind="Index.aspx.cs"
%>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Home Page
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<asp:Label ID="Txt" runat="server" />
</asp:Content>
and in the corresponding code behind Index.aspx.cs (beurk..., I will vomit):
public partial class Index : System.Web.Mvc.ViewPage<AppName.Models.MyViewModel>
{
protected void Page_Load(object sender, EventArgs e)
{
Txt.Text = Model.Title;
}
}
which could be improved like this to avoid the code behind nonsense:
<%# Page
Language="C#"
MasterPageFile="~/Views/Shared/Site.Master"
Inherits="System.Web.Mvc.ViewPage<AppName.Models.MyViewModel>"
%>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Txt.Text = Model.Title;
}
</script>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Home Page
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<asp:Label ID="Txt" runat="server" />
</asp:Content>
I wouldn't recommend you doing something like this if you intend to migrate to ASP.NET MVC 3 and the Razor view engine one day.

I found a solution that's a little cleaner. Still not to my liking, but good enough to wash my hands of this annoying issue.
<% ViewBag.Item = item; %>
<gc:Ribbon runat="server">
<Content>
<strong><%= ViewBag.Item.DataItem.Name %></strong>
</Content>
</gc:Ribbon>
Instead of passing an object into the user control to use within, assign it to the ViewBag (for each iteration if you're looping), and use it globally. If memory serves me right, I believe MVC 2 uses ViewData["loosely typed name"] instead of the dynamic ViewBag.

Related

UpdatePanel not working in default document

My simple application has one page Default.aspx.
If I hit the page at /app/default the page loads and everything works. If i go to /app/ with no file name the page loads but my button does not work.
looking in fiddler I can see a working request starts like
1|#||4|219|updatePanel|MainContent_upDemo|
but a bad request returns the page starting with and the updatepanel javascript can't parse it.
Turning off friendly URLs has the same issue but I now have to go to /app/Default.aspx
<%# Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="CasualFrontEnd._Default" EnableEventValidation="true" %>
<%# Register TagPrefix="cc1" Namespace="EAV" Assembly="EAV" %>
<asp:Content ID="BodyContent" ContentPlaceHolderID="MainContent" runat="server">
<asp:UpdatePanel ID="upCasual" runat="server">
<ContentTemplate>
<asp:Label ID="lblTesting" runat="server" Text="Label"></asp:Label>
<asp:Button ID="BtnApply" CausesValidation="true" runat="server" Text="Apply" OnClick="BtnApply_Click" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
It looks like a bug in the way the default path is handled with no route.
my solution:
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapPageRoute("nofile", "", "~/Default.aspx");
//var settings = new FriendlyUrlSettings();
//settings.AutoRedirectMode = RedirectMode.Temporary;
//routes.EnableFriendlyUrls(settings);
}

My web control doesn't appear in my web page in a different folder

My web control doesn't appear in my web page in a different folder,
However it works in another web page in the same location.
My source code is like this :
..
<%Register src="~/UI/Human/HumanUserControl.wuc" TagPrefix="uc1"
TagName="HumanUserControl"/>
...
<uc1:HumanUserControl runat="Server" id="HumanUserControl"/>
...
Error:
Request is not available in this context
The syntax on your Register tag is incorrect. And I'm not sure why you're using a ".wuc" extension instead of the default ".ascx".
You need matching <% %> tags, like so:
<%# Register Src="~/UI/Human/HumanUserControl.wuc" TagPrefix="uc1" TagName="HumanUserControl" %>
If you delete the <%Register .../> and <uc1 .../> tags from your page completely, then in Visual Studio, drag-and-drop the user control from the Solution Explorer directly onto your page wherever you want the control to appear, it will automatically add the correct Register and user control tags for you.
If this doesn't clear things up, then provide more detailed error information, including the code where the exception is thrown.
The following works just fine:
~/UI/Human/HumanUserControl.ascx
<%# Control Language="C#" AutoEventWireup="true" CodeBehind="HumanUserControl.ascx.cs" Inherits="UserControlTest.UI.Human.HumanUserControl" %>
<asp:Label ID="lblTest" runat="server" />
~/UI/Human/HumanUserControl.ascx.cs
namespace UserControlTest.UI.Human
{
public partial class HumanUserControl : System.Web.UI.UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
lblTest.Text = Request.Browser.Browser;
}
}
}
~/Default.aspx
<%# Page Title="Home Page" Language="C#" MasterPageFile="~/Site.Master" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="UserControlTest._Default" %>
<%# Register Src="~/UI/Human/HumanUserControl.ascx" TagPrefix="uc1" TagName="HumanUserControl" %>
<asp:Content runat="server" ID="BodyContent" ContentPlaceHolderID="MainContent">
<uc1:HumanUserControl runat="server" id="HumanUserControl" />
</asp:Content>

Viewstate and TabPanel

I have been working on a asp.net project last ~6 months where that was one .aspx that was being loaded with different controls. This page and those controls had their own UpdatePanels, etc etc. In other words I had to deal with a bag of viewstate issues. It seems like whenever I think I get viewstate and its details completely I get something like what I am about to describe below. This might have to do with control state, which is from what I understand "necessary" viewstate you cannot turn off. Or this might have to do something with AJAX.
Anyway take a look at this example:
<%# Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" EnableViewState="false" Inherits="ControlDisabledViewStateTesting._Default" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title></title>
<script language="C#" runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (treeView.SelectedNode != null)
ContentPanel.Controls.Add(ContentPanel.TemplateControl.LoadControl("MyUserControl.ascx"));
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<ajx:ToolkitScriptManager runat="server" />
<asp:TreeView ID="treeView" runat="server">
<Nodes>
<asp:TreeNode Text="First Node" Value="111"/>
<asp:TreeNode Text="Second Node" Value="222"/>
</Nodes>
</asp:TreeView>
<Asp:Panel ID="ContentPanel" runat="server" />
</div>
</form>
</body>
</html>
And here is the user control mark up:
<%# Control Language="C#" AutoEventWireup="true" CodeBehind="MyUserControl.ascx.cs" Inherits="ControlDisabledViewStateTesting.MyUserControl" %>
<%# Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajx" %>
<ajx:TabContainer ID="tabContainer" ActiveTabIndex="0" runat="server">
<ajx:TabPanel ID="tab" HeaderText="Tab1" runat="server"/>
<ajx:TabPanel ID="tab2" HeaderText="Tab2" runat="server" />
</ajx:TabContainer>
As you have noticed, Viewstate is turned off on the page level, so none of the controls should be using viewstate.
Click on "First Node".
User control gets loaded with two tabs.
Select the second tab.
Click on "Second Node"
User controls get loaded again, with the "SECOND TAB" selected already.
Is this an issue with viewstate/controlstate or does it have something to do with AJAX part of the TabPanel?
I really appreciate if someone can shed some lights as to what is happening here and how I can turn off this functionality.
Thanks,
Mike
The value for the active tab isn't being stored in view state. It appears to have to do with the ASP.NET AJAX framework and the value is being loaded from the post data.
To change the behavior you could derive from the TabContainer and override the LoadClientState method so that the ActiveTabIndex isn't changed.
You can view the source code for the TabContainer on codeplex:
http://ajaxcontroltoolkit.codeplex.com/SourceControl/changeset/view/1014bf767f65#Server%2fAjaxControlToolkit%2fTabs%2fTabContainer.cs

Asp.net web forms control in asp.net mvc

I'm trying to inject an asp.net classic web control to my asp.net mvc application. This control doesn't use view state or post back so it works fine.
But I can't plug a real-time provided value in its attribute. This code
<my:Control runat="server" Tag="<%: Model.ID %>" />
ends up with the tag value just set explicitly to "<%: Model.ID %>".
Is there a way to make it work?
I believe the syntax is as follows:
<my:Control runat="server" Tag="<%# Model.ID %>" />
The other gotcha is you must call .DataBind() on the Control at some point after the Control has been initialized. This probably means taping into the Page_Load or OnInit events of the Page.
<%# Page Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage" %>
<script runat="server">
protected override void OnInit(EventArgs e)
{
this.Label1.DataBind();
base.OnInit(e);
}
</script>
<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Home Page
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">
<h2><%= Html.Encode(ViewData["Message"]) %></h2>
<asp:Label ID="Label1" runat="server" Text="<%# DateTime.Now %>" />
</asp:Content>
Or, if you have access to the source, you could add a call to .DataBind() somewhere before the final Render. You would have to experiment with that.
Hope this helps.
Well, seems like the only way to do this is injecting code the control renders to the page directly. In my case the control renders a silverlight object with some javascript so I put it at the page as is.

Content control not accessbile from content page?

My content page looks like this:
<%# Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Basket.aspx.cs" Inherits="Basket" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
</asp:Content>
Now, I would like to add some controls dynamically to the content when page loads, so I am trying the following code:
protected void Page_Load(object sender, EventArgs e)
{
Content2. // I want to add controls to it dynamically
}
The problem is that the Content2 control is not visible by the compiler and I am getting error about missing directive or assembly reference.
Any solution?
The reason you can't get a reference to that asp:Content control is because it does not stay around when the page is combined with the masterpage. Basically ASP takes all the controls from inside these asp:Content sections and makes them children of the ContentPlaceholder controls inside the masterpage.
As MSDN says: A Content control is not added to the control hierarchy at runtime. Instead, the contents within the Content control are directly merged into the corresponding ContentPlaceHolder control.
That means that if you want to add more controls to that section, you will have to get a reference to the ContentPlaceholder control in the masterpage and add them to it. Something like:
ContentPlaceHolder myContent = (ContentPlaceHolder)this.Master.FindControl("ContentPlaceHolder1");
myContent.Controls.Add(??);
Notice you are using the ContentPlaceHolderID value, NOT the ID of the asp:Content section.
I will recommend that you put a placeholder control in content and use it to add controls. For example,
<%# Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Basket.aspx.cs" Inherits="Basket" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
<asp:Placeholder runat="server" ID="Content1Controls" />
</asp:Content>
..
And
protected void Page_Load(object sender, EventArgs e)
{
Content1Controls.Controls.Add(...
}

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