Chapter 6

nudirection · May 25th, 2013, 04:50 PM

Hi,
I've been doing OK up until this point; able to find my own mistakes. I am stuck on what went wrong here. The browser page cookie only remembers the drop down selection and does not change the theme. I've enabled the AutoPostBack option and compared the code to the book numerous times.

Imar · May 26th, 2013, 04:07 AM

HI there,

Can you describe where you get stuck? The exercise is done in two parts, so maybe you simply haven't completed the part that assigns the theme in BasePage?

If you did write that code, can you then post the code for the master page (markup and code behind), the Basepage and the page you're testing this on? If you post code, can you please paste it in Notepad first to remove color coding and then use the forum editor's Code toolbar button to wrap your code in code tags. Otherwise, this forum messes up the code.

Cheers,

Imar

nudirection · May 26th, 2013, 10:54 AM

That's entirely possible. I've been following your exercises in order though. Here's the code from the requested pages.

Frontend.master

Code:

<%@ Master Language="VB" CodeFile="Frontend.master.vb" Inherits="MasterPages_Frontend" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Planet Wrox</title>
    <asp:ContentPlaceHolder id="head" runat="server">
    </asp:ContentPlaceHolder>
    <script src="/Scripts/modernizr-2.6.2.js"></script>
</head>
<body>
    <form id="form1" runat="server">
        <div id="PageWrapper">
            <header><a href="/"></a></header>
            <nav>Menu Goes Here</nav>
            <section id="MainContent">
                <asp:ContentPlaceHolder ID="cpMainContent" runat="server">
                </asp:ContentPlaceHolder>
            </section>
            <aside id="Sidebar">
                Select a Theme<br />
                <asp:DropDownList ID="ThemeList" runat="server" AutoPostBack="True">
                    <asp:ListItem>Monochrome</asp:ListItem>
                    <asp:ListItem>DarkGrey</asp:ListItem>
                </asp:DropDownList></aside>
            <footer>Footer Goes Here</footer>
        </div>
    </form>
</body>
</html>

Frontend.master.vb

Code:

Partial Class MasterPages_Frontend
    Inherits System.Web.UI.MasterPage

    Protected Sub ThemeList_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ThemeList.SelectedIndexChanged
        Dim preferredTheme As HttpCookie = New HttpCookie("PreferredTheme")
        preferredTheme.Expires = DateTime.Now.AddMonths(3)
        preferredTheme.Value = ThemeList.SelectedValue
        Response.Cookies.Add(preferredTheme)
        Response.Redirect(Request.Url.ToString())
    End Sub

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
        If Not Page.IsPostBack Then
            Dim selectedTheme As String = Page.Theme
            Dim preferredTheme As HttpCookie = Request.Cookies.Get("PreferredTheme")
            If preferredTheme IsNot Nothing Then
                selectedTheme = preferredTheme.Value
            End If
            If Not String.IsNullOrEmpty(selectedTheme) Then
                Dim item As ListItem = ThemeList.Items.FindByValue(selectedTheme)
                If item IsNot Nothing Then
                    item.Selected = True
                End If
            End If
        End If
    End Sub
End Class

BasePage.vb

Code:

Public Class BasePage
    Inherits System.Web.UI.Page

    Private Sub Page_PreRender(sender As Object, e As EventArgs) Handles Me.PreRender
        If String.IsNullOrEmpty(Me.Title) OrElse Me.Title.Equals("Untitled Page",
                    StringComparison.CurrentCultureIgnoreCase) Then
            Throw New Exception(
              "Page title cannot be ""Untitled Page"" or an empty string.")
        End If
    End Sub
End Class

Default.aspx

Code:

<%@ Page Title="Welcome to Planet Wrox" Language="VB" MasterPageFile="~/MasterPages/Frontend.master" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="cpMainContent" Runat="Server">
    <h1>Hi there visitor and welcome to Planet Wrox</h1>
            <p>We're glad you're paying a visit to <a href="http://www.PlanetWrox.com">www.PlanetWrox.com</a>, the coolest music community site on the Internet.</p>
            <p class="Introduction">Feel free to have a <a href="Default.aspx">look around</a>, there are lots of interesting <strong>reviews and concert pictures</strong> to be found here.</p>
    <p>You can <a href="Login.aspx">log in</a> here.</p>
</asp:Content>

err, I think I may see what you mean about the two-part exercise. I have not completed the 'Applying the User-Selected Theme' exercise yet. I'll continue with that and see what happens.

Thanks Imar.

Regards, Mark

Imar · May 26th, 2013, 11:29 AM

>> I have not completed the 'Applying the User-Selected Theme' exercise yet

I was just going to refer to that ;-) Following that exercise should do the trick.

Cheers,

Imar

nudirection · May 26th, 2013, 02:18 PM

Still getting the same result; defaults to Monochrome theme. Here's my base page file.

BasePage.vb

Code:

Public Class BasePage
    Inherits System.Web.UI.Page

    Private Sub Page_PreRender(sender As Object, e As EventArgs) Handles Me.PreRender
        If String.IsNullOrEmpty(Me.Title) OrElse Me.Title.Equals("Untitled Page",
                    StringComparison.CurrentCultureIgnoreCase) Then
            Throw New Exception(
              "Page title cannot be ""Untitled Page"" or an empty string.")
        End If
    End Sub
    Private Sub Page_PreInit(sender As Object, e As EventArgs) Handles Me.PreInit
        Dim preferredTheme As HttpCookie = Request.Cookies.Get("PreferredTheme")
        If preferredTheme IsNot Nothing Then
            Dim folder As String = Server.MapPath("-/App_Themes/" & preferredTheme.Value)
            If System.IO.Directory.Exists(folder) Then
                Page.Theme = preferredTheme.Value
            End If
        End If
    End Sub
End Class

and Web.Config

Code:

<?xml version="1.0"?>

<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->

<configuration>
    <system.web>
      <pages theme="Monochrome"/>
      <compilation debug="false" strict="false" explicit="true" targetFramework="4.5" />
      <httpRuntime targetFramework="4.5" />
    </system.web>

</configuration>

Imar · May 26th, 2013, 02:34 PM

Take a look at this:

Quote:

Dim folder As String = Server.MapPath("-/App_Themes/" & preferredTheme.Value)

You're using a dash (-) instead of a tilde (~) in front of the App_Themes folder....

Hope this helps,
Imar

nudirection · May 26th, 2013, 02:41 PM

That was it!

Thanks much!