I recently installed YSlow, a handy web development tool for Firefox. In it there is an option that tells you whether your CSS or JavaScript files are cached on the client’s computer allowing for a quicker page load. I noticed my files were not cached so I looked a little into how to go about caching them so the browser won’t download the same file over and over when going from page to page. So I went about conducting my own tests to see how to make this happen. The only way of making it happen other than setting an expire date/time on the WHOLE page (or on the .htaccess file in Linux servers) was to create a server-side file that would output the expiration, content type headers as well as the actual styles/code in your web application. Below is a clearer picture of how I made it happen.

PHP- Step 1.

Make a dynamically generated CSS file that includes expiration and content headers (code below). Save it as ‘dynamic_css.php’. The actual CSS styling can be typed in the same way you would do in a regular stylesheet, we are only after getting those expiration and content type headers sent out.

<?php
header("Expires: Thu, 31 Dec 2020 20:00:00 GMT");
header('Content-type: text/css');
?>
h1 { color: Red; }

PHP- Step 2.

Add ‘dynamic_css.php’ as the CSS href of you document. This should make YSlow happy and increase the speed at which the user navigates through pages that use the same CSS file. Use the same method to add expiration tags to JavaScript.

<link rel="stylesheet" type="text/css" href="dynamic_css.php"/>

ASP- Step 1.

The way I added expire tags to my CSS code in ASP is very similar to PHP’s. First you make a server-side CSS file and save it as ‘dynamic_css.aspx’. Since it is important the headers hit the server first we use server-side code  to send those out first. We type in the actual CSS code like we would in a regular CSS file after that. Besides would you really want to Response.Write() all of your CSS code? I think not.

<%
    Response.Expires = 3600
    Response.ContentType = "text/css"
%>
    h1 { color: Blue; }

ASP- Step 2.

Add ‘dynamic_css.aspx’ as the CSS source of you document. This should make YSlow happy since the expiration headers are now being sent increasing the speed at which the user navigates through the pages that share the same CSS file. Use this same header method to add expiration tags to JavaScript files.

<link rel="stylesheet" type="text/css" href="dynamic_css.aspx"/>

if strVariable1 = “John”
Response.Write(”Welcome John!”)
elseif strVariable1 = “Bob”
Response.Write(”Welcome Bob!”)
else
Response.Write(”Welcome…you.”)

Label1.Text.Request.QueryString(”qtext”)

Dim objConn As OleDbConnection
Dim objRDR As OleDbDataReader
Dim objCmd As OleDbCommand
objConn = New OleDbConnection( _
“Provider=Microsoft.ACE.OLEDB.12.0;Data Source=” & _
“E:Documentsdatabasestest.accdb”)
objCmd = New OleDbCommand(”SELECT [first], [last] FROM [names]“, objConn)
objConn.Open()
objRdr = objCmd.ExecuteReader()
GridView1.DataSource = objRdr
GridView1.DataBind()

<configuration>
<appSettings/>
<connectionStrings configSource=”conns.config”></connectionStrings>
<system.web>
</system.web>
</configuration>

The conns.config file will then only contain a single section element and nothing else. Yes it is that simple.

<connectionStrings>
<add name=”myConnectionString”
connectionString=”Provider=Microsoft.Jet.OLEDB.4.0;
Data Source=C:My Database Foldermydatabase.mdb;
Jet OLEDB:Database Password=mypassword” providerName=”SQLOLEDB”/>
</connectionStrings>

Dim strThemesFolder As String = Server.MapPath("~contentthemes")
'Notice the Array below, a regular string wouldn't be able to hold all those values

Dim strThemeFolders As String() = Directory.GetDirectories(strThemesFolder)
Dim strFolderName As String
For Each strFolderName In strThemeFolders
      Response.Write(strFolderName)
Next

I added this code to my admin files to enable me to change masterfilepages on the fly. I tried with global variables and with properties but my masterpagefile would always default back the hardcoded file somehow.

Private Function changeTheme(ByVal strNewThemePath As String) As String
        If File.Exists(Server.MapPath(strNewThemePath)) Then
            Application.Set("theme", strNewThemePath)
            Return String.Format("Theme changed successfully to: ""{0}""", strNewThemePath)
        Else
            Return String.Format("The file: ""{0}"" does not exist. Theme not changed.", strNewThemePath)
        End If
End Function

Snippet-Global.asax

I also added this to the global.asax file since the code above did not specify a default theme.

    Sub Session_Start(ByVal sender As Object, ByVal e As EventArgs)
        'If no other theme is chosen then load the default
        If Application("theme") Is Nothing Then
            Dim Config As New Config
            Application("theme") = Config.strDefaultTheme
        End If
    End Sub

Sub readFile()
        Dim rdr As StreamReader = New StreamReader(Server.MapPath("test.htm"))
        Me.textAreaControl.InnerText = rdr.ReadToEnd
End Sub

Private mstrName As String
Public Property Name() As String
        Get
            Name = mstrName
           ' Returns default value if nothing has changed it
        End Get
        Set(ByVal pstrName As String)
            mstrName  = pstrName
           'Sets the name to be the newly entered value
        End Set
 End Property

The information can then be retrieved or set as follows:

Dim settingsClass As New 'yourClassName'

Response.Write(settingsClass.Name)
'Returns Cesar
settingsClass.Name = "John"
'Assigns 'John' to the name property
Response.Write(settingsClass.Name)
'Returns John