Paulo Morgado : JavaScript

More On ASP.NET Validators And Validation Summary Rendering of Properties

Paulo Morgado — Mon, 23 Jun 2008 00:47:00 GMT

On previous posts [^][^] I mentioned the size of ASP.NET validators and validation summary rendering and the fact that expando attributes are being used to add properties. Mohamed also mentions this issue.

Besides the fact that custom attributes aren't XHTML conformant, Firefox differs from Internet Explorer in the way it handles these attributes.

On Internet Explorer, these attributes are converted in string properties of the HTML element. On Firefox, on the other hand, these attributes are only accessible through the attributes collection.

I wonder why I don’t like client-side JavaScript development.

Rendering ASP.NET Validators And Validation Summary Property As HTML Attributes

Paulo Morgado — Tue, 13 May 2008 00:34:00 GMT

Yesterday I blogged about the cause of ASP.NET validators and validation summary slowness.

At that point I wasn't aware of the existence of the XHTML conformance configuration (thanks Nuno).

With the XHTML conformance configuration set to Legacy, the rendering of controls works like it worked in ASP.NET 1.1.

The Cause Of ASP.NET Validators And Validation Summary Slowness

Paulo Morgado — Sun, 11 May 2008 23:17:00 GMT

When building ASP.NET pages, if you use too many validators and validation summaries your pages can become very slow. Have you ever wondered why?

Lets build a simple page web page with a few validators. Something like this:

The page is composed of:

2 TextBoxes
1 RequiredFieldValidator for each TextBox
1 RangeValidator for each TextBox
1 CompareValidator
1 ValidationSummary
1 Button

ASP.NET renders the ValidationSummary as a DIV and each validator as a SPAN and uses expando attributes to add properties to those elements.

According to the documentation, expando attributes are set dynamically from JavaScript to preserve XHTML compatibility for the rendered control's markup.

The problem is that all that JavaScript makes the HTML document larger and slower to execute than if the properties were rendered in HTML as attributes of the elements.

For such a small page, the difference in size approaches 2k bytes. If you add a few dozen validators to he page, the slowness is noticeable.

I'm all in favor of strict standards and standards compliance, but in this case, I wish XHTML would allow arbitrary attributes.

JSMock on CodePlex

Paulo Morgado — Thu, 27 Dec 2007 21:57:09 GMT

Bruno has set up a project at CodePlex for his testing framework for JavaScript.

How To Close Browser Windows In Windows Internet Explorer 7

Paulo Morgado — Fri, 02 Nov 2007 01:38:39 GMT

When a web page uses scripting to close a browser window that was opened by the user and not opened by some action on another page, Internet Explorer pops up a question to the user warning that "The webpage you are viewing is trying to close the tab." (in this case, Internet Explorer 7) and asking the user for permission to close the tab.

Before Internet Explorer 7, all that was needed to do was setting the window.opener property to a non null value:

window.opener = self;
window.close();

Unfortunately, Internet Explorer 7 isn't fooled by this. Internet Explorer 7 knows if the window was opened by the user or not, regardless the value of the window.opener property.

Fortunately, Internet Explorer can still be fooled:

window.open("","_self");
window.close();

Going one step further, if you want all your calls to the window.close method to work this way, you can change the method implementation like in the following example:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Untitled Page</title>
    <script type="text/javascript">
    // Save a reference to the original method.
    var windowClose = window.close;

    // Re-implement window.open
    window.close = function ()
    {
        window.open("","_self");
        windowClose();
    }
    </script>
</head>
<body>
<input type="button" value="Close Me!" onclick="window.close()" />
<input type="button" value="Close Me!" onclick="windowClose()" />
</body>
</html>