Add a MicroSummary to any ASP.NET page

Published Oct 4, 2006

Scott Hanselman showed us how to add MicroSummaries to a website using an .ashx file. It was clean and simple, but it would be really cool if we could use the description meta tag instead so we don’t have to maintain two separate files.

I played with the thought and came up with a very simple solution that uses regular expressions to extract the description meta tag from the rendered page and outputs it in the response stream. It works by listening for a querystring called microsummary, and it even outputs the correct link tag to the head section of the page.

The only thing you need is a <head runat=”server”> on your ASP.NET 2.0 page. Keep in mind that this solution only works if you have a description meta tag on you page, otherwise it will just output the title of the page. It consist of two methods – one that generates the link tag and one that outputs the description as a MicroSummary. Then just call these methods from the Page_Load or preferably as soon as possible in the page life cycle such as Page_PreInit. It depends on when you set the description meta tag.

protected void Page_Load(object sender, EventArgs e)

{

if (!Page.IsPostBack && !Page.IsCallback)

{

if (Request.QueryString["microsummary"] != null)

{

WriteMicroSummary();

}

else

{

SetMicroSummaryLinkInHeader();

}

private void WriteMicroSummary()

{

using (StringWriter sw = new StringWriter())

{

Page.Header.RenderControl(new HtmlTextWriter(sw));

string html = sw.ToString();

string lookFor = "<meta name=\"description\" content=\"";

Match match = Regex.Match(html, lookFor + @"[^""]*""", RegexOptions.IgnoreCase);

if (match.Success)

{

string description = match.Captures[0].Value.ToLower().Replace(lookFor, string.Empty);

Response.Write(description.Substring(0, description.Length - 1));

}

else

{

Response.Write(Page.Title);

}

Response.End();

}

} >

private void SetMicroSummaryLinkInHeader()

{

HtmlLink ms = new HtmlLink();

ms.Attributes["rel"] = "microsummary";

ms.Attributes["type"] = "application/x.microsummary+xml";

string url = Request.RawUrl + "{0}microsummary=1";

if (Request.RawUrl.Contains("?"))

ms.Href = string.Format(url, "&");

else

ms.Href = string.Format(url, "?");

Page.Header.Controls.Add(ms);

}

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