How can I validate CSS on internal web pages?

Question

I want to check internal web pages, so I cannot use the W3C validation service directly. I managed to run the XHTML validator locally, however, I have some problems with the css-validator. I do not really want to setup Tomcat or Jigsaw in order to be able to run Java servlet, and the commandline option gives me an error message

Exception in thread "main" java.lang.NoClassDefFoundError: 
org.w3c.tools.resources.ProtocolException at 
org.w3c.css.css.CssValidator.main(CssValidator.java:164)

How can I validate local CSS on a Linux box?

Answer 1

That jar is runnable, but it needs some extra libraries.

Examine the MANIFEST.MF file:

$ unzip -p css-validator.jar META-INF/MANIFEST.MF
Manifest-Version: 1.0
Ant-Version: Apache Ant 1.8.0
Created-By: 1.6.0_26-b03 (Sun Microsystems Inc.)
Main-Class: org.w3c.css.css.CssValidator
Class-Path: . lib/commons-collections-3.2.1.jar lib/commons-lang-2.6.j
 ar lib/jigsaw.jar lib/tagsoup-1.2.jar lib/velocity-1.7.jar lib/xerces
 Impl.jar lib/xml-apis.jar lib/htmlparser-1.3.1.jar

You need all the jars mentioned in Class-Path. You can download them from the maven repository using this script:

#!/bin/bash

set -e

mkdir -p lib
curl -LO http://www.w3.org/QA/Tools/css-validator/css-validator.jar
echo "\
http://repo1.maven.org/maven2/commons-collections/commons-collections/3.2.1/commons-collections-3.2.1.jar
http://repo1.maven.org/maven2/commons-lang/commons-lang/2.6/commons-lang-2.6.jar
http://repo1.maven.org/maven2/org/w3c/jigsaw/jigsaw/2.2.6/jigsaw-2.2.6.jar jigsaw.jar
http://repo1.maven.org/maven2/org/ccil/cowan/tagsoup/tagsoup/1.2/tagsoup-1.2.jar
http://repo1.maven.org/maven2/org/apache/velocity/velocity/1.7/velocity-1.7.jar
http://repo1.maven.org/maven2/xerces/xercesImpl/2.11.0/xercesImpl-2.11.0.jar xercesImpl.jar
http://repo1.maven.org/maven2/nu/validator/htmlparser/htmlparser/1.2.1/htmlparser-1.2.1.jar\
" | while read url shortname; do
        if [ -z "$shortname" ]; then
            shortname="${url##*/}"
        fi
        curl -L -o "lib/${shortname}" "${url}"
    done

After doing that, it works:

$ java -jar css-validator.jar --output=soap12 file:badcss.html
{vextwarning=false, output=soap12, lang=en, warning=2, medium=all, profile=css3}
<?xml version='1.0' encoding="utf-8"?>
<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope">
    <env:Body>
        <m:cssvalidationresponse
            env:encodingStyle="http://www.w3.org/2003/05/soap-encoding"
            xmlns:m="http://www.w3.org/2005/07/css-validator">
            <m:uri>file:badcss.html</m:uri>
            <m:checkedby>http://jigsaw.w3.org/css-validator/</m:checkedby>
            <m:csslevel>css3</m:csslevel>
            <m:date>2013-03-12T06:40:09Z</m:date>
            <m:validity>false</m:validity>
            <m:result>
                <m:errors xml:lang="en">
                    <m:errorcount>1</m:errorcount>

                <m:errorlist>
                    <m:uri>file:badcss.html</m:uri>

                        <m:error>
                            <m:line>8</m:line>
                            <m:errortype>parse-error</m:errortype>
                            <m:context> h1 </m:context>        
                            <m:errorsubtype>
                                exp
                            </m:errorsubtype>
                            <m:skippedstring>
                                100%
                            </m:skippedstring>

                            <m:message>

                                Property fnt-size doesn&#39;t exist : 
                            </m:message>
                        </m:error>

                    </m:errorlist>

                </m:errors>
                <m:warnings xml:lang="en">
                    <m:warningcount>1</m:warningcount>

                    <m:warninglist>
                        <m:uri>file:badcss.html</m:uri>

                        <m:warning>
                            <m:line>5</m:line>
                            <m:level>0</m:level>
                            <m:message>You should add a &#39;type&#39; attribute with a value of &#39;text/css&#39; to the &#39;style&#39; element</m:message>
                        </m:warning>

                    </m:warninglist>
                    </m:warnings>
            </m:result>
        </m:cssvalidationresponse>
    </env:Body>
</env:Envelope>

Answer 2

You can invoke the W3C validator from the command line:

Command-Line use

Any computer with Java installed can also run the validator from the terminal/console as a commandline tool. Download the css-validator.jar jar archive (or build it with ant jar) and run it as :

java -jar css-validator.jar http://www.w3.org/

Note : the css-validator.jar file must be located at the exact same level as the lib/ folder to work properly.

Update: To get it to work, I checked out the full distribution from CVS and ran ant using the included build.xml. It downloaded all dependencies except for servlet.jar. To deal with that, I downloaded the binary distribution of Tomcat 6 and extracted it. Then, I edited the build.xml for css-validator to reflect the location of servlet.lib:

<property name="servlet.lib" 
 value="E:/Downloads/apache-tomcat-6.0.20/lib/servlet-api.jar"/>

Then ran ant again. This produced the css-validator.jar file in the top level of the directory checked out from CVS with the lib subdirectory containing the other jars it depends on. Then, I was able to run the validator successfully:

C:\Temp\validator\2002\css-validator> java -jar css-validator.jar http://www.unur.com/

Answer 3

For the lazy, here's a script I wrote to do what Sinan suggests:

#!/bin/sh
# W3C CSS Validator Install Script --------------
# installs W3C CSS Validator
# requires: ant, wget, javac
# see: http://jigsaw.w3.org/css-validator/DOWNLOAD.html
# see: http://esw.w3.org/CssValidator
# see: http://thecodetrain.co.uk/2009/02/running-the-w3c-css-validator-locally-from-the-command-line/
# see: http://stackoverflow.com/a/3303298/357774
##wget "http://www.w3.org/QA/Tools/css-validator/css-validator.jar"
#sudo aptitude install -y ant # uncomment if you don't have ant
CVSROOT=:pserver:anonymous:[email protected]:/sources/public cvs checkout 2002/css-validator 
mkdir 2002/css-validator/lib
TOMCAT6_VERSION='6.0.45'
wget "http://www.apache.org/dist/tomcat/tomcat-6/v$TOMCAT6_VERSION/bin/apache-tomcat-$TOMCAT6_VERSION.tar.gz"
tar xvf apache-tomcat-$TOMCAT6_VERSION.tar.gz
mv apache-tomcat-$TOMCAT6_VERSION/lib/servlet-api.jar 2002/css-validator/lib/servlet.jar
rm -rf apache-tomcat-$TOMCAT6_VERSION apache-tomcat-$TOMCAT6_VERSION.tar.gz
cd 2002/css-validator
ant jar
# usage example: java -jar css-validator.jar "http://csszengarden.com/"

That should work, at least until the next software dependency update breaks the ant build script (feel free to parameterize versions).

Hope this helps!