I was debating whether to call this release version 1.1 or 2.0 because it contains quite a lot of new functionality. I’ve decided to stick with 1.1 since it also features a lot of fixes and tweaks to the current functionality. Download it at the VS Gallery. Now, let’s take a tour of the new features.

Option dialog

This was the top requested feature from the original Web Essentials for Visual Studio 2010. It finally made it in.


You can set the most important options through this dialog. If I forgot some options, please let me know so I can add them for the next release.

JSHint for JavaScript

JSHint is a really good way of making sure your JavaScript follows certain coding guidelines and best practices. The default settings are very relaxed, but you can turn on more rules through the new options dialog.


The error window updates as you type, so you don’t have to right-click the .js file to kick off JSHint. It happens as you write.

Better LESS and CoffeeScript

The LESS editor has been updated with the latest functionality that is needed to truly take advantage of LESS. This includes:

  • Support for @import directives
  • Intellisense across imported .less files for Mixins and variables
  • All the validation from the CSS editor now shows up in LESS
  • Both CoffeeScript and LESS now uses the official compilers
  • Compiles and creates a .css/.js file when a LESS/CoffeeScript file is saved in VS

JavaScript regions

Some people hate them, other people loves them. This is a feature that was in the original Web Essentials 2010 an by popular request now made it in the 2012 version.


Re-embed base64 dataURIs

The problem with embedding your images as base64 dataURI’s is to keep it up-to-date with the original image file as it changes. Now you can.


Vendor help for @-directives

Vendor specific validation and Smart Tags are now also available for @-directives.


New performance validation

Three new validators have been added that analyses the CSS for general performance issues. They validation the following:

  1. Small images should be inlined (base64 embedded)
  2. Don’t use the universal selector (the star)
  3. Don’t over qualify ID selectors

They can be turned on/off in the new options dialog.

Other small features

  • Simple-selector highlighting like C#’s identifier highlighting
  • Option to place validation messages in either Messages, Warnings or Errors
  • Diff any 2 files in Solution Explorer. Might be useful for diffing LESS and CSS
  • Collapse long base64 dataURI’s
  • Auto-insert closing curly with type-through support
  • New LESS and CoffeeScript item templates. More to come in next version

Bug fixes

Thank you so much for reporting bugs. That is really helpful and increases the quality of the extension in general. Here are some of the bugs reported by the users:

  • Invalid LESS and CoffeeScript would result in an ugly error message and crash VS sometimes
  • Intellisense for animation-name now also applies to animation
  • LESS formatting for negative units no longer inserts an invalid space
  • Dark theme now works for the browser support tooltip
  • Mustache/Handlebars no longer screws up JSON strings
  • Wrongly inserted color swatches for LESS variables


Visual Studio 2012 will alert you of this update if you already have the previous version of Web Essentials installed. If not or VS didn’t alert you yet, go download it at the VS Gallery.


The CSS editor in Visual Studio has unprecedented support for both W3C standards and vendor specific properties, pseudos and @-directives. See the full list here. However, not all vendor specific prefixes are supported, just the major ones: -moz-, -ms-, -o- and -webkit-. In case you have to target really old versions of Safari, it would be nice to have -khtml- as well. Visual Studio 2012 makes it very easy to add support for new properties or to augment existing ones with additional values.

An easy VS extension

Visual Studio extensions or VSIX packages as they are called, have a reputation of being notoriously difficult to write and the documentation is lacking. For adding your own custom schema to the CSS editor, this is most definitely not the case. In fact, it couldn’t be easier.

Step 1: Download and install the Visual Studio 2012 SDK

The SDK is needed for Visual Studio to know how to open extensibility project types.

Step 2: Download the CustomCssSchema project  and open it in VS2012

This project contains the custom -khtml- schema and the ability to compile into an extensibility package – a VSIX. The project is very small as shown below.


The only 2 files we care about for this scenario are the /Schemas/css-vendor-khtml.xml and KhtmlSchemaProvider.cs files. The rest of the files are used by the VSIX to display the right icons and descriptions in the Visual Studio Extension Manager as well as on the VS Gallery website. They are pretty self-explanatory once you open them and look at what they do.

The CSS schema

The css-vendor-khtml.xml schema file is not a complete KHTML schema. It is merely an examples to get you started. Check it out here. It makes it possible to create brand new properties, pseudos and @-directives. You can even inherit from properties already supported by VS and you can add additional property values to existing properties. It’s all explained in the XML file.

The schema provider class

The KhtmlSchemaProvider class is responsible for registering your XML schema file with the CSS editor. It is really simple as you can see below:


That’s all the class does.

Get started

After downloading the SDK and the CustomCssSchema project, just hit F5 in Visual Studio. That launches an instance of Visual Studio. This extensibility instance is called the Experimental instance. Now open a .css file in the Experimental instance and check to see if the -khtml- properties are present in Intellisense. If they are, you are ready to start customizing the css-vendor-khtml.xml file.

The different ways to extend the schema is all explained inside the css-vendor-khtml.xml file itself, so I won’t go in to details here.

You can add multiple XML schema files. As many as you like, actually. Just make sure to create corresponding SchemaProvider classes as well.

Publishing the extension

You are now done with your custom CSS schema extension and want to put it on the VS Gallery for everyone to download. First, you need to locate the .vsix file that is produced every time you build the CustomCssSchema project. It’s in the bin folder.


Now go to the VS Gallery website and sign in using your Live ID credentials. After signing in, this button becomes visible:


Click it. It takes you to the first step of the little upload wizard.


Choose “Tool” and click Next to show the next step where you are going to upload the .vsix file.


Step 3 is basically about adding some tags and descriptions.

That’s it. Your VSIX is now available for everybody to download!!

Extra benefits

When building custom schemas, you get some added benefits you might didn’t consider.

1. Snippets are automatically created to include your custom properties.

All the vendor specific snippets in VS2012 are auto-generated based on the schema files. That means that if you include -khtml-border-radius in your custom schema, that property will now be included in the regular border-radius snippet.


2. Works in LESS and SCSS too

Any editor that is built on top of the VS2012 CSS editor will get the same Intellisense for your custom schema. One such editor is the LESS editor included in Web Essentials 2012.

Happy coding!


Today is a big day for all ASP.NET web developers. Both Visual Studio 2012, Windows 8 and Windows Server 8 is being released to MSDN subscribers.

Web Essentials 2012 logoIt is also the day that the first version of Web Essentials for Visual Studio 2012 is being released, or simply Web Essentials 2012. Download it here

As we developed the brand new CSS editor in VS2012, we did it with extensibility in mind. The first Web Essentials for VS2010 already demonstrated what could be done with the old CSS editor, but we wanted to make sure we wouldn’t run into any shortcomings in the extensibility model for VS2012. So the development of Web Essentials 2012 started back in January and it helped shape the extensibility of both the HTML and CSS editors.

Here are some of the most interesting new features.

Browser compatibility checks

Did you remember to use all the vendor specific CSS properties? How would you know if you didn’t? Don’t worry, Web Essentials uses VS2012’s CSS schemas to find out for you. Those schema files are up-to-date with all the vendor specific properties.

You can do quick checks on any property, pseudo class/element or @-directive to get a overview of what browsers are supporting the particular thing your mouse is hovering over. In this case the border-radius property:


In case there are any issues with your CSS file’s browser compatibility, the Messages list will be used to display them.


I’ve build a website that shows you exactly what’s supported by the VS2012 CSS editor. Web Essentials for VS2010 also had this feature, but it has been approved immensely in the new version and is a lot more accurate and up-to-date.

Clicking one of the browser compatibility errors takes you directly to the place in your CSS file where the error occurred. You can now use a Smart Tag to add the missing vendor specific properties.


In a big CSS file, going through the errors one-by-one can be a little time consuming, so it would be nice if you could perform some of these actions for the entire file in just a single click.


See the numbers 1-4 in the context menu? They are numbered like that for a reason. To clean up your stylesheet, start clicking the first menu item. Then move to number 2, then 3 and lastly 4. This ensures that things are done in the right order.

I’ve tested this on really big CSS files up to 15,000 lines with hundreds of browser compatibility errors and it only took a few seconds to run the auto-fix.

LESS, CoffeeScript and Sass

Good news for any LESS or CoffeeScript fans and semi-good news for Sass fans. The LESS editor is the most evolved of the three and you get all the goodness that Web Essentials 2012 brings to CSS directly in your LESS files. CoffeeScript and Sass (only .sass files, not .scss yet!) are supported in terms of colorization, formatting and outlining/code-folding.


The LESS editor does a lot more than just colorize nicely as shown above. It gives you full Intellisense for variables and Mixin’s as well.


Also variables gets a first-class treatment in Intellisense. Hovering a variable will also show you its value.


For both LESS and CoffeeScript, a preview window is shown on the right side of the editor where the compiled CSS or JavaScript respectively, are displayed.


Every time the LESS or CoffeeScript document is saved, the preview window is updated to reflect the changes. Sass doesn’t have this ability in this first release of Web Essentials, but it’s coming. So is support for the new Sass syntax, often referred to as SCSS.

Paste JSON as classes

When you have to work with JSON and especially JSON REST API’s, it can be time consuming and cumbersome to create all your C# classes after what an API is returning. With Web Essentials 2012, that is now very easy.

Let’s say you copied this example JSON from the documentation of some JSON API out on the web.


You could construct the C# class manually based on this JSON string. But you could also just right-click in the C# editor.


Clicking Paste JSON As Classes will parse the copied JSON string from the clipboard and convert it into C# classes.


It uses JSON.NET behind the scenes, just like ASP.NET Web API does, so by using them together you will know that the serialization and deserialization is working as expected.

Improved color workflow

The color squares introduced in Web Essentials for VS2010 has been vastly improved. They now cover all types of colors, including all the new CSS 3 specific color formats.


The color converter has also been updated accordingly.


Let’s say you want to slightly darken or lighten a color in your stylesheet. That is now very easy using SHIFT+CTRL+ARROW UP/DOWN when the cursor is located on a hex color value. I don’t have a image demoing this, so you will have to imagine that the color changes its brightness. The color stays the same, but the brightness is adjusted.

The same shortcut key combination can be used to change any number values as well as move properties or whole rules up and down in the document.

Intellisense everywhere

A lot of work has been put into making Intellisense appear everywhere you might need it. Even as a URL auto-completer.


Animation names are also populated from the keyframes or any vendor specific keyframes implementation as well.


CSS 3 font embedding is of course also supported.


Even the more important ones are covered.


HTML elements, class names and ID’s? Yep, got that too.


And a whole lot more.

Download Web Essentials 2012

So that was a brief overview of just a few of the features that I like the most, but there is so much more. Head over to the VS Gallery and check out a list of all the other features available.

Download Web Essentials 2012


I’ve been asked this question so many times lately, that a blog-post-answer seemed appropriate. There will be a Web Essentials for Visual Studio 2012!

The original Web Essentials for Visual Studio 2010 quickly became popular amongst web developers in the fall of 2011, when it was first released. Primarily, I think, because it added a lot of missing functionality to the CSS editor. It made working with CSS less painful and more fun – like it should be.

It was flawed, it was slow and it didn’t always feel very accurate. Most of these issues were fixed, but some still remain. I had to parse all the CSS manually using regular expression and other techniques and that had a lot of side effects. In fact, everything was done manually. It wasn’t pretty, but it worked for the most part.

Web Essentials for VS2010

Web Essentials for VS2012

Web Essentials for VS2012 will be different. The performance is spectacular and it feels – and  is – very accurate. The reason for this is largely due to the vast amount of feedback people submitted from the original Web Essentials. Bug reports and feature request still keeps coming in every week.

image image image
Intellisense for HTML tags, class names and ID’s in CSS selectors. Web Essentials 2012

All that feedback also made a huge difference in our priorities when building the brand new CSS editor in VS2012. We basically threw the old editor out after shipping VS2010 and started completely from scratch.  We didn’t do a lot of specifications, instead we prototyped a bunch of different ideas, iterated on them and finally implemented them. The time it takes to write a good spec is about the same time it takes to build a prototype, so it was a perfect way to be creative and come up with solid solutions.

The CSS experience in VS2012 is so much better than it ever was and significantly raises the bar for CSS editors in the industry, IMHO. So what role would Web Essentials play and was it even needed in VS2012 and beyond? Well, not all prototypes made it in the product. Also, not all features from the original Web Essentials made it either.

Right-click in the CSS editor to perform document-wide fixes in Web Essentials 2012.

So, I’ve been slowly porting Web Essentials, piece by piece, to Visual Studio 2012 to test the CSS editor for the past 6 months. Combine that with all the prototypes and experiments that never made it into VS and you have a good starting point for the next version of Web Essentials. Oh, and throw in a more friendly and helpful version of CssCop into the mix too.

New message types helps identify browser compatibility problems and helps with best practices

The ultimate goal of Web Essentials have always been to increase developer happiness by exceeding the expectations of what you would think possible in a CSS editor. Providing big features that really make an impact is always fun and hopefully helpful as well. Smaller features and even smaller details can have an equally big impact and I think that is the theme of the new Web Essentials – details with a big impact.

Synchronizing values of vendor specific properties in Web Essentials 2012

Not everything in the original Web Essentials was about CSS. It contained features for both HTML and JavaScript. However, most of those features actually made it into VS2012. That’s great, but that doesn’t mean that there isn’t useful features to be added outside of CSS.

Mustache/Handlebar support in the HTML editor for JavaScript templating and data binding

This is the first post in a series about the upcoming Web Essentials 2012. Later I’ll go more into detail about the individual features (there’s a lot!) and show some code. This was a primer and an overdue answer to the question.

Web Essentials 2012 will be available when Visual Studio 2012 RTM is released.

Teaser: Check out the prototype in this Channel 9 video.


Not everybody is able to upgrade to Visual Studio 2012 RC due to company policy or other reasons, but that doesn’t mean you can’t get some of its CSS 3 support in Visual Studio 2010 today. Whether or not you’ve got Web Standards Update installed or not, this is for you.

We’ve been able to port some of the support from Visual Studio 2012 into a format that is understood by Visual Studio 2010, but a lot of it I’ve had to port manually. Before proceeding, you should know that this is completely unsupported and at your own risk.

Here’s how to patch your installation of VS2010.

1. Download the new CSS 3 schema file

2. Locate the current CSS schema files. Mine are located at C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\Packages\1033\schemas\CSS. If you customized your install directory, then it’s located somewhere else, but the path should be similar.

3. If you have a file called css30.xml (from Web Standards Update), then replace it with the new downloaded file. If you don’t have css30.xml, then replace css21.xml with the downloaded file. I recommend you backup the old file before overriding it – just in case.

4. Restart Visual Studio 2010.


Visual Studio 2010 doesn’t support some of the new CSS 3 constructs and unit types. This new schema file will not help with that. It can’t. What you do get is all the standard and vendor specific properties with Intellisense and validation to the degree Visual Studio 2010 supports it.

Because a portion of this new schema was edited manually by me, it is possible that it contains a few bugs. Please report them in the comments if you find any, so I can get it fixed.