How to suppress specific CSS 2.0 validation errors in Visual Studio 2008?

Tags: asp.net,visual-studio-2008,css

Problem :

A typical CSS property that I use often is overflow-x or overflow-y. Sometimes I use CSS 2.1 or later properties or selectors. These (correctly) raise a validation error:

Validation (CSS 2.0): 'overflow-y' is not a known CSS property name.

For years I ignored this, but it kinda feels wrong. It's possible to switch off warnings in C# and other languages for a particular line, block, file or project. Is something similar possible for CSS (or HTML) errors or warnings? Instead of switching it all off, I prefer a more granular solution.

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Solution :

If you're willing to muck around a bit you can get exactly what you want.

1. Go to Visual Studio folder \Common7\Packages\1033\schemas\CSS
2. Copy css21.xml to css21mod.xml

3. Find the section:

   <cssmd:property-def _locID="overflow" ...
   

4. After that section, insert:

   <cssmd:property-def 
       _locID="overflow-x" _locAttrData="description,syntax" 
       type="enum" 
       description="Visibility of content extending beyond element's dimensions in x"
       syntax="One of the overflow values | inherit" 
       enum="inherit auto hidden scroll visible"/>
   
   <cssmd:property-def 
       _locID="overflow-y" _locAttrData="description,syntax" type="enum" 
       description="Visibility of content extending beyond element's dimensions in y" 
       syntax="One of the overflow values | inherit" 
       enum="inherit auto hidden scroll visible"/>
   

5. Open regedit, go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\VisualStudio\9.0\Packages\{A764E895-518D-11d2-9A89-00C04F79EFC3}\Schemas

   If on 64-bit, you will have to go to SOFTWARE\Wow6432Node\Microsoft etc

6. Create a new key called Schema 5, and fill in the "File" and "Friendly Name" string values with css21mod.xml and CSS 2.1 (mod)

Should be all set!