To understand how rules extension works in Sonar, please refer to the Extending Coding Rules documentation.

Extending PHP_Codesniffer Rules

PHP_CodeSniffer is built on an extensible architecture where you can define you own rules.

To do so, you just have to create your own rules.xml file following the below format:

<?xml version="1.0" encoding="ISO-8859-1"?>
<rules>
  <rule key="PEAR.Commenting.FileComment.TagIndent" priority="MAJOR">
    <category name="Maintainability" />
    <name>Tag comment incorrectly indented</name>
    <configKey>TAG_INDENT</configKey>
    <description>@category tag comment incorrectly indented</description>
  </rule>
</rules>

This file must be copied in the directory $SONAR_HOME/extensions/rules/php_codesniffer_rules/. You have to restart your Sonar server to make it available for PHP profiles.

The value of the "key" attribute is a combination of different elements: <standard_folder>.<sniff_subfolder>.<sniff_file_without_Sniff_suffix>.<error_name>.
For instance, for the given key above ("PEAR.Commenting.FileComment.TagIndent"):

• "PEAR" is the folder found in the "Standards" directory of PHPCodeSniffer install directory
• "Commenting" is the folder found in the "Sniffs" directory of the "PEAR" folder
• "FileComment" is the name of the PHP file "FileCommentSniff.php" for which "Sniff.php" was removed
• "TagIndent" is the name of the error that can be found in "FileCommentSniff.php" file

Extending PHPMD Rules

Extending PHPMD works the same way as PHP_CodeSniffer, except that you have to copy your file containing your custom violations in $SONAR_HOME/extensions/rules/phppmd_rules/

This XML file must look like the following example:

<?xml version="1.0" encoding="ISO-8859-1"?>
<rules>
  <rule key="Code Size Rules/CyclomaticComplexity" priority="CRITICAL">
    <name><![CDATA[Class cyclomatic complexity exceed maximum]]></name>
    <configKey>rulesets/codesize.xml/CyclomaticComplexity</configKey>
    <category name="Maintainability"/>
    <description><![CDATA[Class cyclomatic complexity exceed maximum]]></description>
    <param key="maximum" type="i">
      <description><![CDATA[The maximum cyclomatic complexity threshold. Default is 10.]]></description>
    </param>
  </rule>
<!-- other rules ... -->
</rules>