ASP.NET Parsing raw HTML into Controls

Question

Is it possible in ASP.NET to take a string containing some HTML and make ASP.NET to parse it and create a Control for me? For example:

string rawHTML = "<table><td><td>Cell</td></tr></table>";
HTMLTable table = MagicClass.ParseTable(rawHTML);

I know that this is a bad thing to do but I am in the unfortunate situation that this is really the only way I can achieve what I need (as I cannot modify this particular coworker's code).

Also, I know that LiteralControl allows you to have a control with arbitrary HTML in it, but unfortunately I need to have them converted to proper control.

Unfortunately, HTMLTable does not support the InnerHTML property. I need to preserve the HTML tree exactly as it is, so I cannot put it into a <div> tag.

Thanks.

Mark Brackett · Accepted Answer · 2008-10-29 21:43:47Z

7

The closest I think you'll get is Page.ParseControl, which is the ASP.NET parser. The downside is that the text you have is a LiteralControl, since it doesn't have runat="server" on it - so you 'll do a very tiny bit of string manipulation beforehand.

In otherwords:

this.ParseControl("<table><tr><td>Cell</td></tr></table>")

will produce:

Control
 LiteralControl

whereas:

this.ParseControl("<table runat=\"server\"><tr><td>Cell</td></tr></table>")

will produce:

Control
 HtmlTable
  HtmlTableRow
   HtmlTableCell
    LiteralControl

answered Oct 29, 2008 at 21:43

Mark Brackett

85.9k17 gold badges113 silver badges156 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

trnelson Over a year ago

This seems super weird to me but I have to say, I'm kind of in love with it. Never heard of it, but just happens to be exactly what I need right now.

Mike Over a year ago

One tip for anyone using this approach in a library - ParseControl will fail unless you provide a value for the AppRelativeVirtualPath attribute on the Page object. For example in VB: Dim pg As New Web.UI.Page pg.AppRelativeVirtualPath = "~\\"

Stephen Wrighton · Accepted Answer · 2008-10-29 21:20:20Z

0

You could traverse the HTML string a token at a time (token defined here as HTML Element or HTML InnerText), and determine which control needs to be instantiated, and what attributes it needs. But, that would be something highly... evil in the writing.

Why exactly do you need it to be a "proper" control as opposed to a text inside of a Literal control?

answered Oct 29, 2008 at 21:20

Stephen Wrighton

38.1k6 gold badges72 silver badges88 bronze badges

1 Comment

Mkkt Bkkt Over a year ago

The code I have to use (and unfortunately cannot modify) is meant to populate a PlaceHolder with some HTMLControl objects and later on it inspects these elements and does some stuff based on that. Unfortunately I only have the raw HTML contents of the PlaceHolder so I need to recreate it.

Collectives™ on Stack Overflow

ASP.NET Parsing raw HTML into Controls

2 Answers 2

2 Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related