Package com.puppycrawl.tools.checkstyle.checks.coding

Class RequireThisCheck

  • All Implemented Interfaces:
    Configurable, Contextualizable
    public class RequireThisCheck
extends AbstractCheck

    Checks that code doesn't rely on the "this" default. That is references to instance variables and methods of the present object are explicitly of the form "this.varName" or "this.methodName(args)".

    Check has the following options:

    checkFields - whether to check references to fields. Default value is true.

    checkMethods - whether to check references to methods. Default value is true.

    validateOnlyOverlapping - whether to check only overlapping by variables or arguments. Default value is true.

    Warning: the Check is very controversial if 'validateOnlyOverlapping' option is set to 'false' and not that actual nowadays.

    Examples of use: 

     <module name="RequireThis"/>
    An example of how to configure to check this qualifier for methods only: 
     <module name="RequireThis">
   <property name="checkFields" value="false"/>
   <property name="checkMethods" value="true"/>
 </module>

    Rationale:

    1. The same notation/habit for C++ and Java (C++ have global methods, so having "this." do make sense in it to distinguish call of method of class instead of global).
    2. Non-IDE development (ease of refactoring, some clearness to distinguish static and non-static methods).

    Limitations: Nothing is currently done about static variables or catch-blocks. Static methods invoked on a class name seem to be OK; both the class name and the method name have a DOT parent. Non-static methods invoked on either this or a variable name seem to be OK, likewise.

    • Field Detail

      • MSG_METHOD

        public static final java.lang.String MSG_METHOD
        A key is pointing to the warning message text in "messages.properties" file.
        See Also:
        Constant Field Values

      • MSG_VARIABLE

        public static final java.lang.String MSG_VARIABLE
        A key is pointing to the warning message text in "messages.properties" file.
        See Also:
        Constant Field Values

    • Constructor Detail

      • RequireThisCheck

        public RequireThisCheck()

    • Method Detail

      • setCheckFields

        public void setCheckFields​(boolean checkFields)
        Setter for checkFields property.
        Parameters:
        checkFields - should we check fields usage or not.

      • setCheckMethods

        public void setCheckMethods​(boolean checkMethods)
        Setter for checkMethods property.
        Parameters:
        checkMethods - should we check methods usage or not.

      • setValidateOnlyOverlapping

        public void setValidateOnlyOverlapping​(boolean validateOnlyOverlapping)
        Setter for validateOnlyOverlapping property.
        Parameters:
        validateOnlyOverlapping - should we check only overlapping by variables or arguments.

      • getDefaultTokens

        public int[] getDefaultTokens()
        Description copied from class: AbstractCheck
        Returns the default token a check is interested in. Only used if the configuration for a check does not define the tokens.
        Specified by:
        getDefaultTokens in class AbstractCheck
        Returns:
        the default tokens
        See Also:
        TokenTypes

      • getRequiredTokens

        public int[] getRequiredTokens()
        Description copied from class: AbstractCheck
        The tokens that this check must be registered for.
        Specified by:
        getRequiredTokens in class AbstractCheck
        Returns:
        the token set this must be registered for.
        See Also:
        TokenTypes

      • getAcceptableTokens

        public int[] getAcceptableTokens()
        Description copied from class: AbstractCheck
        The configurable token set. Used to protect Checks against malicious users who specify an unacceptable token set in the configuration file. The default implementation returns the check's default tokens.
        Specified by:
        getAcceptableTokens in class AbstractCheck
        Returns:
        the token set this check is designed for.
        See Also:
        TokenTypes

      • beginTree

        public void beginTree​(DetailAST rootAST)
        Description copied from class: AbstractCheck
        Called before the starting to process a tree. Ideal place to initialize information that is to be collected whilst processing a tree.
        Overrides:
        beginTree in class AbstractCheck
        Parameters:
        rootAST - the root of the tree

      • leaveToken

        public void leaveToken​(DetailAST ast)
        Description copied from class: AbstractCheck
        Called after all the child nodes have been process.
        Overrides:
        leaveToken in class AbstractCheck
        Parameters:
        ast - the token leaving