The spying of users activity is good for you business !

Web analytics are an important part for a website; it allows the site owner to understand what users are looking for and to enhance his site in order to grab more users.

Web Analytics systems.

One of the most popular system is google analytics, if you have a google account, you can use this system for your sites.
You just have to create an entry for your website on www.google.com/analytics.
It generates for you a piece of code with a specific ID that you have to paste just before the closing head tag of each of the pages you want to monitor.

An alternative is Piwik, which is open source.
This web application has to be installed on a web server (with php/mysql).
This app also generates for you a piece of javascript code that you have to paste right before the closing body tag.

With ASP.NET Webforms.

In ASP.NET Webform you can copy this tracking code on your main Master page and it’s included in all pages using this master page.
But it requires modifying the page and redeploying the web site.

You can also use the Global.asax to add code to each page which is generated. It also requires redeployment.

Another alternative are the httpmodules.
It allows you to add functionalities to a website with just copying a dll file in the bin directory of your application and reference it in your main web.config file.

It’s the solution I choose in order to add analytics functionality to a website already running.

SAHM for Simple Analytics HttpModule.

My first implementation added only google tracking code, but I added piwik just in case and because I was testing this system.

I made it public, so you can download it from codeplex at the address : http://sahm.codeplex.com/

To use it:

1.) Copy the SAHM.dll file in the bin folder of your application

2.) Edit your Web.Config application file.

2.1) Locate <configSections> and add

<sectionGroup name="SAHM">
 <section name="google" type="SAHM.GoogleConfig, SAHM" allowLocation="true" allowDefinition="Everywhere"/>
 <section name="piwik" type="SAHM.PiwikConfig, SAHM" allowLocation="true" allowDefinition="Everywhere"/>
</sectionGroup>

2.1) Add a SAHM section

<SAHM>
 <google Code="UA-XXXXXX-X"/>
 <piwik Server="www.yourpiwikserver/" IDSite="1"/>
</SAHM>

Set your identifiers.

For the piwik : be sure to set the Server value without the “http://”

2.3) Add the module in the <module>

<httpModules>
 <add name="SAHM" type="SAHM.AnalyticsModule, SAHM"/>
 </httpModules>

or if you use II7

<system.webServer>
 <modules runAllManagedModulesForAllRequests="true"/>
 </system.webServer>

2.4) Save your web.config file and test if your tracking code is in your page code.

2.5) That’s it

If you enjoy this module, please let me know!
Happy web traffic analyses.

Download link : http://sahm.codeplex.com/

When we are developping with databound controls, a common action is to retreive controls (like dropdownlists) in an objectdatasource’s “Inserting” event.

Here is a specific example :

In the InsertItemTemplate of a ListView:

<asp:ObjectDataSource runat="server" ID="MyDataSource"
 // ... />

<asp:DropDownList runat="server"
       ID="MyDDL"
       DataSourceID="MyDataSource"
       DataTextField="TheText"
       DataValueField="TheValue"/>

Do:

protected void TheDataSource_Inserting(object sender, ObjectDataSourceMethodEventArgs e)
{
    if (MyListView.InsertItem == null)
       return;

     DropDownList myDDL= MyListView.InsertItem.FindControl("MyDDL") as DropDownList;
     if (myDDL== null)
         return;
     if (string.IsNullOrEmpty(myDDL.SelectedValue))
         return;

    e.InputParameters["TheWantedValue"] = myDDL.SelectedValue;
 }

Don’t:

protected void TheDataSource_Inserting(object sender, ObjectDataSourceMethodEventArgs e)
{
    e.InputParameters.Add("TheWantedValue", ((DropDownList)MyListView.InsertItem.FindControl("MyDDL")).SelectedValue);
}

This for an obvious reason : you can’t always be sure that a problem won’t pop up.

A random problem can occur anywhere, whether the dropdownlist population or something else

So, be safe and protect yourself !

This post is relative to the first episode of the “ASP.NET do and don’ts serie”

ASP.NET contains several validation controls. Be sure to use the good ones for your needs.

Imagine you have the following dropdownlist

<asp:DropDownList runat="server" ID="MyDDL"
      // datasource params
     AppendDataBoundItems="true">
     <asp:ListItem Text="select a value" Value="-1" Selected="True" />
</asp:DropDownList>

Do:

<asp:RequiredFieldValidator runat="server" ID="MyDDLValidator" ControlToValidate="MyDDL" ErrorMessage="Selection required" InitialValue="-1" />

Don’t:

<asp:CompareValidator runat="server" ID="MyDDLValidator"
 ValueToCompare="-1" ControlToValidate="MyDDL"
 Operator="NotEqual" ErrorMessage="Selection required" />

There are many controls you can use for the navigation in ASP.NET.

Be sure that you use the good ones for the good uses.

Let say we want a link on a page to redirect on an other page

Do:

in the aspx markup

<asp:HyperLink runat="server" ID="NavigateToOtherPage" NavigateUrl="~/otherpage.aspx" Text="Go to the other page" />

or even better if you just want to redirect on a page

<a href="otherpage.aspx">Go to the other page</a>

Don”t:

in the aspx markup

<asp:LinkButton runat="server" ID="NavigateToOtherPage" Text="Go to the other page" onclick="RedirectToOtherPage" />

and in the code behind

protected void RedirectToOtherPage(object sender, EventArgs e)
{
     Response.Redirect("~/otherpage.aspx");
}

This is the first post of a serie on the ASP.NET practices.

For this serie, I get inspiration from what I see in my daily work or on the web

Don’t use custom validator when you can use an other control !

Do:

in the aspx markup

<asp:TextBox runat="server" ID="FeedURLTbx"  />

<asp:RegularExpressionValidator runat="server"
     ID="URLFormatValidator"
     ControlToValidate="FeedURLTbx"
     ValidationExpression="(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&amp;:/~\+#]*[\w\-\@?^=%&amp;/~\+#])?"
     Text="!"
     ErrorMessage="The URL format is not valid." />

Don’t:

in the aspx markup

<asp:TextBox runat="server" ID="FeedURLTbx"  />

 <asp:CustomValidator runat="server" ID="URLFormatValidator"
 ControlToValidate="FeedURLTbx"
 ErrorMessage="The URL format is not valid."
 OnServerValidate="ValidateURL" />

and in the aspx code behind

protected void ValidateURL(object source, ServerValidateEventArgs args)
{

System.Text.RegularExpressions.Regex myRegExp = new  System.Text.RegularExpressions.Regex(@"(http|ftp|https):\/\/[\w\-_]+(\.[\w\-_]+)+([\w\-\.,@?^=%&:/~\+#]*[\w\-\@?^=%&/~\+#])?");

args.IsValid = myRegExp.IsMatch(args.Value);
}

Why??

First because the RegularExpressionValidator is designed for string validations and it’s a non sense to do the same with another control !

Second because the CustomValidator used like here will cause a postback while the RegularExpressionValidator will generate the validation javascript and don’t cause postback.

With the RegularExpressionValidator :

With the CustomValidator :

I think the first reason is enough to not discuss the point !