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?

Experimental

See my updated answer with build instructions. – Cure

...or see my updated answer that automates the whole thing! https://mcmap.net/q/641330/-how-can-i-validate-css-on-internal-web-pages – Richma

Why are people so narrow minded? There is no reason to close this question... but then who cares! – Experimental

is reported as an error since a short time: github.com/w3c/css-validator/issues/246 – Svetlana

Answer 1

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/

Plovdiv

Well.. I tried that, but I get above error message. I am not sure that I understand the meaning of the note. It does not work either if put into the /lib folder. Which lib folder is meant here? – Experimental

I think I get it. I downloaded the source code from CVS from dev.w3.org/cvsweb/2002/css-validator ... I have not built it yet, but it seems like running the validator from the command line still needs to be in the context of Jigsaw. I think that is the /lib directory the docs are referring to. – Cure

Apparently Jigsaw's servlet.jar is now included with the css-validator source: 2002/css-validator/tmp/Jigsaw/classes/servlet.jar – Waterlog

I added a simplified, scripted solution for the lazy below. Just copy-paste and wait! – Richma

Answer 2

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>

Essentialism

The download path for lib/xml-apis.jar seems to be missing? – Wu

@SlavenRezic That jar has the interfaces in the javax.xml package, but those are included with Java now. You should only need to add it for very old versions of Java that don’t include it. If you download the JAR it won’t even be used unless you use the endorsed standards override mechanism. – Essentialism

This script got me close, but the css-validator also requires the org directory from the CVS tree - @Noyo's answer contains the missing bit: env CVSROOT=:pserver:anonymous:[email protected]:/sources/public cvs checkout 2002/css-validator; mv 2002/css-validator/org/ . – Suazo

This should definitely be the accepted answer! It is ridiculous that these libraries aren't included in the downloadable JAR, and that it doesn't say in the documentation that they're absent! Thank you @andrewdotn! – Plumper

I had to adapt http: to https:, and because my version wants htmlparser-1.3.1, I use the line https://repo1.maven.org/maven2/org/htmlparser/htmlparser/1.6/htmlparser-1.6.jar htmlparser-1.3.1.jar – Svetlana

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: https://mcmap.net/q/641330/-how-can-i-validate-css-on-internal-web-pages
##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!

Richma

404 on the download link, here's the current one: newverhost.com/pub/tomcat/tomcat-6/v6.0.29/bin/… – Octodecimo

Thanks! I updated the script to grab $TOMCAT6_VERSION (easily updated by whomever wants to use the script) directly from apache. – Richma

I updated Tomcat version above however before running ant jar I needed to also change a version number using sed -i 's/commons-collections-3.2.1/commons-collections-3.2.2/g' build.xml. If someone can confirm this is correct we can update the script above. – Bonanno

Answer 4

You can now use the new Linux command line tool htmlval for checking HTML and CSS. It should definitely work for validating local CSS on a Linux box.

Note: I'm the developer.

Pleasurable