Mastering jQuery now available at TekPub

AJAX, ASP.NET, JavaScript, jQuery By . Updated September 1, 2010

Mastering jQuery

If you haven’t been following the progress of Rob Conery and James Avery’s new venture, TekPub, you’ve been missing out on some great instructional videos. I especially like that they trend slightly Alt.NET, giving you more balanced information than is sometimes available from “official” .NET screencasts.

For the past few weeks, I’ve been working with James to record a series of episodes for TekPub myself: Mastering jQuery.

Mastering jQuery walks through the basics of using jQuery, the revolutionary JavaScript framework that makes writing client-side code fun and easy, and then dives into the details of writing AJAX enabled ASP.NET MVC and ASP.NET Web Forms applications. We will also cover popular plugins and extending jQuery in future episodes.

Today, the first video in that series is available: Getting Started with jQuery.

In this episode we cover the basics of getting started with jQuery. We start with a basic HTML page and show how to include jQuery, how to write your first code, and explain all of the moving pieces and how they work.

If you’ve been following my site and working with jQuery already, the first episode may sound elementary, but there’s going to be something for everyone before the series is finished. By the third episode, we’re already into topics like making AJAX calls to MVC controller actions and progressively enhancing an entry form with the jQuery form plugin.

I hope you’ll head over to TekPub, and have a look for yourself.

Emulate ASP.NET validation groups with jQuery validation

AJAX, ASP.NET, JavaScript, jQuery, UI By . Updated August 5, 2011

In my most recent post, I demonstrated a workaround to allow using the jQuery validation plugin with WebForms pages. The basic idea was to trigger validation only on submissions that occurred within a single logical form, instead of catching submissions anywhere on WebForms’ all-encompassing physical form.

This approach worked fine for a single logical form, but wasn’t robust enough when handling validation for multiple logical forms on a single page. Additionally, it did not properly handle the enter key, allowing users to (perhaps accidentally) slip past validation if they simply hit the enter key within a TextBox.

In this post, we will continue by refining the solution from last time. So, if you haven’t read the previous post, familiarize yourself with it first. Specifically, this post will cover how to implement an analogue of WebForms’ ValidationGroup, use that to independently validate multiple form regions, handle the enter key, and refactor the final solution to minimize duplicated code.

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Using jQuery validation with ASP.NET WebForms

AJAX, ASP.NET, jQuery, UI By . Updated November 24, 2009

Validation Sticker

You’ve probably noticed that Jörn Zaefferer’s jQuery validation plugin has been gaining momentum in the ASP.NET community lately. Between Microsoft’s implied endorsement via ASP.NET MVC 2.0 integration and the plugin’s recent inclusion on the Microsoft AJAX CDN, adoption is only increasing. Unfortunately for those who don’t or can’t use ASP.NET MVC yet, using the validation plugin within WebForms applications can be tricky.

Because the WebForms Postback model requires that the entire page be contained within a single form element, form submissions that shouldn’t trigger validation are likely. ASP.NET’s built-in validation controls solve this with ValidationGroups and the CausesValidation property, but that doesn’t help if you’d prefer to use the jQuery validation plugin.

However, there are a couple relatively easy workarounds that make it possible to use the jQuery validation plugin on WebForms pages, without re-architecting the page or its forms. In this post, I’ll show you why the WebForms page structure is a problem, how to make jQuery validation work with it, and an example of implementing those workarounds.

Note: I want to preface this by saying that you should never rely entirely on client-side validation. The jQuery validation plugin can be a great replacement for the client-side part of the ASP.NET Validators, but it is not a complete replacement on its own. Use responsibly!

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Highslide JS .NET v4.1.5

ASP.NET, Highslide, UI By . Posted August 25, 2009

Though the version number only inched up 0.0.1 with this release, it brings quite a few new features; most of them in response to your requests. I can’t include every request, but I will continue to improve the control based on your feedback, so keep them coming.

Changes in v4.1.5 include:

  • Updated the base Highslide JS library to v4.1.5.
  • Updated the embedded CSS to the latest version bundled with Highslide JS. This fixes the issue with the transparent/blank bar during enlargement if a caption is set.
  • A few internal improvements that should make it work more reliably in some situations.

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Get early access to ASP.NET AJAX in Action, Second Edition

AJAX, ASP.NET, JavaScript, Reading By . Updated August 21, 2009

The book cover of ASP.NET AJAX in Action, 2nd EditionIf you’ve been reading long, you might remember that I’ve been a fan of ASP.NET AJAX in Action since the original was published. By avoiding heavy reliance on drag ‘n drop methodologies, the Manning book leaves readers with a deeper understanding of the framework.

Without understanding the underlying mechanisms well, developing successful solutions is as much a function of luck as it is skill; especially when it comes to debugging and maintenance. So, I think a comprehensive book like this is absolutely essential.

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Simplify calling ASP.NET AJAX services from jQuery

AJAX, ASP.NET, JavaScript, jQuery By . Posted July 21, 2009

As jQuery’s popularity in the .NET community has risen over the past year, one recurring theme I’ve seen is the desire to refactor away the details of using it to call ASP.NET AJAX services. Whether through helper function or specialized jQuery plugin, I’ve seen numerous methods proposed and/or in use.

Personally, the syntax never bothered me. The contentType parameter is ugly, but I have a Visual Studio code snippet for the $.ajax call and rarely think about it.

That came to an end earlier this year, when I started using dataFilter. I needed to isolate my code from the “.d” issue, and wanted to take advantage of browser-native JSON parsing in Firefox 3.5 and IE8, which required a bulky dataFilter.

Repeating that entire callback function in every $.ajax call was not acceptable. So, I was happy to learn that jQuery provides an excellent solution for consolidating settings to be used in multiple instances of $.ajax.

In this post, I’ll show you how to use that consolidation feature, and exactly how I am now using that to more simply call ASP.NET AJAX services with jQuery.

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Improving jQuery’s JSON performance and security

AJAX, ASP.NET, JavaScript, jQuery By . Posted July 7, 2009

When you’re working with JSON, performance and security are often opposing, yet equally important concerns. One of these areas of contention is handling the JSON strings returned by a server. Most JavaScript libraries do a great job of abstracting away the details, but the underlying process has long been a frustrating exercise in compromise.

On one hand, eval() is the fastest widely available method, but it is not safe.

On the other hand, textual JSON parsers written in JavaScript may be much safer, but are dramatically slower. In client-side situations, where milliseconds count, such a large performance overhead is typically too prohibitive to accept.

Recently, an exciting new alternative has emerged: browser-native JSON parsing. Integrating JSON parsing as part of the browser’s implementation of JavaScript allows for using the more secure parsing method, and even provides performance faster than eval() offers.

To take advantage of that, this post will show you how to detect whether or not a browser supports native JSON parsing, and how to force jQuery to use browser-native parsing in its $.ajax calls when it is available.

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Never worry about ASP.NET AJAX’s .d again

AJAX, ASP.NET, JavaScript, jQuery By . Updated August 2, 2009

When I recently received this message from a frustrated reader:

After hours and hours of slamming my head into the desk it turns out it was the darn "d" in the response. My home computer is on .NET 2.0 and my work computer is on 3.5. Jimminie Christmas!

I realized that the “.d” introduced in ASP.NET AJAX 3.5’s JSON responses is still all too common a stumbling block when calling ASP.NET AJAX services through a library such as jQuery. In fact, with jQuery’s popularity among ASP.NET developers on the rise, this appears to have become an even more frequent problem.

Since a lot of people are having trouble with it, I want to share one method you can use to completely isolate your code from the problem. If you bake this into an $.ajax() code snippet or otherwise use it as a template for calling ASP.NET AJAX services in jQuery, you should never have to think or worry about the “.d” again.

In this post, I will show you how to detect the “.d” and how you can completely isolate your $.ajax success handler from it.

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Hear me talk about jQuery on the Polymorphic Podcast

ASP.NET, JavaScript, jQuery By . Posted June 20, 2009

As a longtime listener myself, I was eager when Craig asked me to come on the Polymorphic Podcast to talk about jQuery. I’ve always enjoyed how he doesn’t shy away from talking about HTML and JavaScript, which is still too uncommon in the .NET world.

With that in mind, I knew we’d be able to have a great conversation about jQuery and the concerns that ASP.NET developers run into when using it. I really enjoyed recording the show, and think it turned out pretty well. I hope you’ll enjoy it too:

Polymorphic Podcast: jQuery Secrets with Dave Ward

If you haven’t yet, I highly recommend subscribing to Craig’s podcast. There are some real gems in his previous shows too, so check those out as well.

11 keystrokes that made my jQuery selector run 10x faster

ASP.NET, CSS, JavaScript, jQuery, Performance By . Updated June 30, 2010

As an ASP.NET developer working on the client-side, one problem you’ll encounter is how to reference the HTML elements that ASP.NET web controls generate. All too often, you find yourself wasting time trying to reference TextBox1, when the element is actually rendered as ctl00_panel1_wizard1_TextBox1.

Much has been written about this, including a post of my own, so I won’t go into detail about many of the workarounds. Instead, I want to take a closer look at the performance drawbacks of one popular solution: the [attribute$=value] selector.

By specifying id as the attribute in this selector, you can avoid ASP.NET’s ClientID issues completely. No matter what the framework prefixes your rendered elements with, they still “end with” the ID you specify at design time. This makes the “ends with” selector a convenient alternative to injecting a control’s ClientID property via angle-brackets.

However, are we trading performance for this convenience? If so, how much?

When Craig Shoemaker asked that question while interviewing me for an upcoming episode of Polymorphic Podcast, I realized I didn’t know the answer as clearly as I’d like. So, I decided to do a bit of benchmarking.

In this post, I’ll share the results of that benchmarking, and show you one way to significantly improve the performance of this convenient selector.

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