Cs-doclet
Cs-doclet is a doclet that generates the metadata files for CheckStyle checks and filters from 'doc tags' in the source files.
This tool is useful for developers of CheckStyle checks and filters, and their integration in eclipse-cs.
Extending CheckStyle
CheckStyle comes with an API to extend the standard set of checks and filters:
File "src/com/pany/cs/checks/ColorCheck.java":
package com.pany.cs.checks; import com.puppycrawl.tools.checkstyle.api.Check; import com.puppycrawl.tools.checkstyle.api.DetailAST; import com.puppycrawl.tools.checkstyle.api.TokenTypes; public class ColorCheck extends Check { public void setColor(String value) { this.color = value; } private String color = "Yellow"; @Override public int[] getDefaultTokens() { return new int[] { TokenTypes.ANNOTATION }; } @Override public void visitToken(DetailAST ast) { this.log(ast, "theColorIs", this.color); } }
This API supports internationalization be means of "messages.properties" files:
File "src/com/pany/cs/checks/messages.properties":
theColorIs = The color is {0}
File "src/com/pany/cs/checks/messages_de.properties":
theColorIs = Die Farbe ist {0}
Then you'd write a "CheckStyle configuration file", and execute CheckStyle on a target project, e.g. itself:
File "checkstyle-config.xml":
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE module PUBLIC "-//Puppy Crawl//DTD Check Configuration 1.3//EN" "http://www.puppycrawl.com/dtds/configuration_1_3.dtd"> <module name="Checker"> <property name="severity" value="warning" /> <module name="TreeWalker"> <module name="com.pany.cs.checks.ColorCheck"> <property name="color" value="blue" /> </module> </module> </module>
$ javac -d bin src/com/pany/cs/checks/ColorCheck.java $ java -classpath bin;path/to/checkstyle-6.1-all.jar \ > com.puppycrawl.tools.checkstyle.Main \ > -c checkstyle-config.xml \ > -r src Starting audit... C:\dev\EclipseWS\de.unkrig.cs-contrib\foo\src\com\pany\cs\checks\ColorCheck.java:33:5: warning: The color is 'blue' C:\dev\EclipseWS\de.unkrig.cs-contrib\foo\src\com\pany\cs\checks\ColorCheck.java:36:5: warning: The color is 'blue' Audit done. $
Obviously, the Java code and the "messages.properties" files must be kept in sync with the Java code at all times, which is naturally very error-prone.
Cs-doclet facilitates the task by generating the "messages.properties" file from doc tags in the source code:
File "src/com/pany/cs/checks/MyCheck.java":
package com.pany.cs.checks; import com.puppycrawl.tools.checkstyle.api.Check; import com.puppycrawl.tools.checkstyle.api.DetailAST; import com.puppycrawl.tools.checkstyle.api.TokenTypes; public class ColorCheck extends Check { /** @cs-message The color is {0} */ public static final String MESSAGE_KEY_THE_COLOR_IS = "theColorIs"; public void setColor(String value) { this.color = value; } private String color = "Yellow"; @Override public int[] getDefaultTokens() { return new int[] { TokenTypes.ANNOTATION }; } @Override public void visitToken(DetailAST ast) { this.log(ast, MESSAGE_KEY_THE_COLOR_IS, this.color); } }
To generate the "messages.properties" file, you'd run JAVADOC with the cs-doclet and the "-messages.properties-dir" command line option:
$ javadoc \ > -doclet de.unkrig.doclet.cs.CsDoclet \ > -docletpath path/to/cs-doclet.jar;bin;path/to/checkstyle-6.1-all.jar;path/to/net.sf.eclipsecs.core-6.1.jar > -messages.properties-dir src > -sourcepath src > -classpath ../net.sf.checkstyle-6.1/checkstyle-6.1/checkstyle-6.1-all.jar Loading source files for package com.pany.cs.checks... Constructing Javadoc information... $
Notice that both "checkstyle.jar" and "net.sf.eclipsecs-core.jar" must be on the "-docletpath".
The generated "messages.properties" file looks like this:
# This file was generated by the CS doclet; see http://cs-contrib.unkrig.de # Custom check messages, in alphabetical order. # --------------- com.pany.cs.ColorCheck --------------- theColorIs = The color is {0}
Now all the documentation of the check and its property "color" is where it belongs: In the source code.
Integrating with eclipse-cs
When you integrate your checks with eclipse-cs, then you learn that you have to write two more metadata files:
File "checkstyle-metadata.xml":
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE checkstyle-metadata PUBLIC "-//eclipse-cs//DTD Check Metadata 1.1//EN" "http://eclipse-cs.sourceforge.net/dtds/checkstyle-metadata_1_1.dtd"> <checkstyle-metadata> <rule-group-metadata name="%Whitespace.group" priority="999"> <rule-metadata internal-name="com.pany.cs.checks.ColorCheck" parent="TreeWalker" name="%com.pany.cs.checks.ColorCheck.name" > <alternative-name internal-name="com.pany.cs.checks.ColorCheck" /> <description>%com.pany.cs.checks.ColorCheck.desc</description> <property-metadata name="color" datatype="String" default-value="Yellow" > <description>%com.pany.cs.checks.ColorCheck.color</description> </property-metadata> <message-key key="theColorIs" /> </rule-metadata> </rule-group-metadata> </checkstyle-metadata>
File "checkstyle-metadata.properties":
Whitespace.group = Whitespace com.pany.cs.checks.ColorCheck.name = com.pany.cs.ColorCheck com.pany.cs.checks.ColorCheck.desc =\ A completely useless check which merely prints a (localizable) message each \ time it encounters an annotation. com.pany.cs.checks.ColorCheck.color = A completely useless check parameter.
Tedious, isn't it? Well, you can tell cs-doclet to also generate these files from doc comments:
File "src/com/pany/cs/checks/MyCheck.java":
// File "src/com/pany/cs/ColorCheck.java". package com.pany.cs.checks; import com.puppycrawl.tools.checkstyle.api.Check; import com.puppycrawl.tools.checkstyle.api.DetailAST; import com.puppycrawl.tools.checkstyle.api.TokenTypes; /** * A completely useless check which merely prints a (localizable) message each time it encounters an annotation. * * @cs-rule-group %Whitespace.group * @cs-rule-name com.pany.cs.ColorCheck * @cs-rule-parent TreeWalker */ public class ColorCheck extends Check { /** @cs-message The color is {0} */ public static final String MESSAGE_KEY_THE_COLOR_IS = "theColorIs"; /** * A completely useless check parameter. * * @cs-property-name color * @cs-property-datatype String * @cs-property-default-value Yellow */ public void setColor(String value) { this.color = value; } private String color = "Yellow"; @Override public int[] getDefaultTokens() { return new int[] { TokenTypes.ANNOTATION }; } @Override public void visitToken(DetailAST ast) { this.log(ast, MESSAGE_KEY_THE_COLOR_IS, this.color); } }
$ javadoc \ > -doclet de.unkrig.doclet.cs.CsDoclet \ > -docletpath path/to/cs-doclet.jar;bin;path/to/checkstyle-6.1-all.jar;path/to/net.sf.eclipsecs.core-6.1.jar > -checkstyle-metadata.properties-dir src > -checkstyle-metadata.xml-dir src > -messages.properties-dir src > -sourcepath src > -classpath ../net.sf.checkstyle-6.1/checkstyle-6.1/checkstyle-6.1-all.jar Loading source files for package com.pany.cs.checks... Constructing Javadoc information... $
And you'll get:
File "src/com/pany/cs/checks/checkstyle-metadata.properties":
# This file was generated by the CS doclet; see http://cs-contrib.unkrig.de. # Rule groups: Whitespace.group = Whitespace # Custom checks, in alphabetical order. # --------------- com.pany.cs.ColorCheck --------------- com.pany.cs.checks.ColorCheck.name = com.pany.cs.ColorCheck com.pany.cs.checks.ColorCheck.desc =\ A completely useless check which merely prints a (localizable) message each time it encounters an annotation. com.pany.cs.checks.ColorCheck.color = A completely useless check parameter.
File "src/com/pany/cs/checks/checkstyle-metadata.xml":
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE checkstyle-metadata PUBLIC "-//eclipse-cs//DTD Check Metadata 1.1//EN" "http://eclipse-cs.sourceforge.net/dtds/checkstyle-metadata_1_1.dtd"> <checkstyle-metadata> <rule-group-metadata name="%Whitespace.group" priority="999"> <rule-metadata internal-name="com.pany.cs.checks.ColorCheck" parent="TreeWalker" name="%com.pany.cs.checks.ColorCheck.name" > <alternative-name internal-name="com.pany.cs.checks.ColorCheck" /> <description>%com.pany.cs.checks.ColorCheck.desc</description> <property-metadata name="color" datatype="String" default-value="Yellow" > <description>%com.pany.cs.checks.ColorCheck.color</description> </property-metadata> <message-key key="theColorIs" /> </rule-metadata> </rule-group-metadata> </checkstyle-metadata>
MediaWiki markup documentation
Typically, you will also want to publish human-readable documentation for your checks and filters, which is more or less identical with the text in the eclipse-cs files. This is also possible with the "-mediawiki-dir" command line option:
$ javadoc \
> -doclet de.unkrig.doclet.cs.CsDoclet \
> -docletpath path/to/cs-doclet.jar;bin;path/to/checkstyle-6.1-all.jar;path/to/net.sf.eclipsecs.core-6.1.jar
> -checkstyle-metadata.properties-dir src
> -checkstyle-metadata.xml-dir src
> -messages.properties-dir src
> -mediawiki-dir mediawiki
> -sourcepath src
> -classpath ../net.sf.checkstyle-6.1/checkstyle-6.1/checkstyle-6.1-all.jar
Loading source files for package com.pany.cs.checks...
Constructing Javadoc information...
$
This will generate:
File "mediawiki/com.pany.cs.ColorCheck.mw":
A completely useless check which merely prints a (localizable) message each time it encounters an annotation.
== Properties == Default values appear underlined.
- color = "String" (optional; default value is Yellow)
- A completely useless check parameter.
Upload this text to a MediaWiki repository, and you'll see: