Applications, both on native and on the web, generally fall into two categories. Most are utilitarian, with a lot of investment in functionality and little or no active involvement from graphic artists beyond the initial mock-ups. Then there are the ones that focus on appearance first, with full-fledged user interface designers working alongside the programmers every step of the way. These people are often expected to work directly with the HTML, MXML, or XAML.
The story of XAML is a mixed one. It takes a lot of effort by the programmers to ensure their code works correctly in Blend’s design-time environment. But if they do it, the user interface designers can see exactly what the finished product is going to look like just as if they were using an HTML/CSS tool.
For ASP.NET MVC, the picture is far worse. While it has made great strides in making development easier, Michael Taylor argues that the technology regressed in other ways.
But there is a problem in MVC land. We're building UIs so why can't I visually see what my page is going to look like within the designer? It brings back memories of the ASP/HTML days where you'd write your UI and then run IE to see what it looks like. From a UI designer perspective this is insane. One of the really big features of ASP.NET (and perhaps Visual Interdev) was that I could write my UI and then switch over and view it without leaving VS. I could even drag and drop controls onto the form and voila I could make changes until it is just right. No such ability in MVC.
Michael’s specific complaints are easy to understand. Without the ability to render the MVC blocks at design time, there is no way to see how changes to the CSS will affect the view in the designer. That said, there are workarounds available. One option would be to run the site and copy the generated HTML into a static file. From there the designer can play with the styling using whatever tools they prefer.
Another problem plaguing the industry is the inability to see browser-specific rendering issues. Like most tools, Visual Studio doesn’t warn developers when they use techniques that may not be compatible across browsers. So designers are left with the unenviable task on manually examining each browser to see if their CSS actually works.