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NAME

Perl::Critic::Config - Find and load Perl::Critic user-preferences

DESCRIPTION

Perl::Critic::Config takes care of finding and processing user-preferences for Perl::Critic. The Config object defines which Policy modules will be loaded into the Perl::Critic engine and how they should be configured. You should never really need to instantiate Perl::Critic::Config directly because the Perl::Critic constructor will do it for you.

CONSTRUCTOR

new( [ -profile => $FILE, -severity => $N, -theme => $string, -include => \@PATTERNS, -exclude => \@PATTERNS, -single-policy => $PATTERN, -top => $N, -only => $B, -strict-profile => $B, -force => $B, -verbose => $N, -color => $B ] )
new()

Returns a reference to a new Perl::Critic::Config object. The default value for all arguments can be defined in your .perlcriticrc file. See the "CONFIGURATION" section for more information about that. All arguments are optional key-value pairs as follows:

-profile is a path to a configuration file. If $FILE is not defined, Perl::Critic::Config attempts to find a .perlcriticrc configuration file in the current directory, and then in your home directory. Alternatively, you can set the PERLCRITIC environment variable to point to a file in another location. If a configuration file can't be found, or if $FILE is an empty string, then all Policies will be loaded with their default configuration. See "CONFIGURATION" for more information.

-severity is the minimum severity level. Only Policy modules that have a severity greater than $N will be loaded into this Config. Severity values are integers ranging from 1 (least severe) to 5 (most severe). The default is 5. For a given -profile, decreasing the -severity will usually result in more Policy violations. Users can redefine the severity level for any Policy in their .perlcriticrc file. See "CONFIGURATION" for more information.

-theme is special string that defines a set of Policies based on their respective themes. If -theme is given, only policies that are members of that set will be loaded. See the "POLICY THEMES" section for more information about themes. Unless the -severity option is explicitly given, setting -theme causes the -severity to be set to 1.

-include is a reference to a list of string @PATTERNS. Policies that match at least one m/$PATTERN/imx will be loaded into this Config, irrespective of the severity settings. You can use it in conjunction with the -exclude option. Note that -exclude takes precedence over -include when a Policy matches both patterns.

-exclude is a reference to a list of string @PATTERNS. Polices that match at least one m/$PATTERN/imx will not be loaded into this Config, irrespective of the severity settings. You can use it in conjunction with the -include option. Note that -exclude takes precedence over -include when a Policy matches both patterns.

-single-policy is a string PATTERN. Only the policy that matches m/$PATTERN/imx will be used. This value overrides the -severity, -theme, -include, -exclude, and -only options.

-top is the maximum number of Violations to return when ranked by their severity levels. This must be a positive integer. Violations are still returned in the order that they occur within the file. Unless the -severity option is explicitly given, setting -top silently causes the -severity to be set to 1.

-only is a boolean value. If set to a true value, Perl::Critic will only choose from Policies that are mentioned in the user's profile. If set to a false value (which is the default), then Perl::Critic chooses from all the Policies that it finds at your site.

-strict-profile is a boolean value. If set to a true value, Perl::Critic will make certain warnings about problems found in a .perlcriticrc or file specified via the -profile option fatal. In particular, Perl::Critic normally only warns about profiles referring to non-existent Policies, but this option makes this situation fatal.

-force controls whether Perl::Critic observes the magical "## no critic" pseudo-pragmas in your code. If set to a true value, Perl::Critic will analyze all code. If set to a false value (which is the default) Perl::Critic will ignore code that is tagged with these comments. See "BENDING THE RULES" for more information.

-verbose can be a positive integer (from 1 to 10), or a literal format specification. See Perl::Critic::Violations for an explanation of format specifications.

-color is not used by Perl::Critic but is provided for the benefit of perlcritic.

METHODS

add_policy( -policy => $policy_name, -params => \%param_hash )

Creates a Policy object and loads it into this Config. If the object cannot be instantiated, it will throw a fatal exception. Otherwise, it returns a reference to this Critic.

-policy is the name of a Perl::Critic::Policy subclass module. The 'Perl::Critic::Policy' portion of the name can be omitted for brevity. This argument is required.

-params is an optional reference to a hash of Policy parameters. The contents of this hash reference will be passed into to the constructor of the Policy module. See the documentation in the relevant Policy module for a description of the arguments it supports.

policies()
Returns a list containing references to all the Policy objects that have been loaded into this Config. Objects will be in the order that they were loaded.
exclude()
Returns the value of the -exclude attribute for this Config.
include()
Returns the value of the -include attribute for this Config.
force()
Returns the value of the -force attribute for this Config.
only()
Returns the value of the -only attribute for this Config.
strict_profile()
Returns the value of the -strict-profile attribute for this Config.
severity()
Returns the value of the -severity attribute for this Config.
single_policy()
Returns the value of the -single-policy attribute for this Config.
theme()
Returns the Perl::Critic::Theme object that was created for this Config.
top()
Returns the value of the -top attribute for this Config.
verbose()
Returns the value of the -verbose attribute for this Config.
color()
Returns the value of the -color attribute for this Config.

SUBROUTINES

Perl::Critic::Config has a few static subroutines that are used internally, but may be useful to you in some way.

site_policy_names()
Returns a list of all the Policy modules that are currently installed in the Perl::Critic:Policy namespace. These will include modules that are distributed with Perl::Critic plus any third-party modules that have been installed.

CONFIGURATION

Most of the settings for Perl::Critic and each of the Policy modules can be controlled by a configuration file. The default configuration file is called .perlcriticrc. Perl::Critic::Config will look for this file in the current directory first, and then in your home directory. Alternatively, you can set the PERLCRITIC environment variable to explicitly point to a different file in another location. If none of these files exist, and the -profile option is not given to the constructor, then all Policies will be loaded with their default configuration.

The format of the configuration file is a series of INI-style blocks that contain key-value pairs separated by '='. Comments should start with '#' and can be placed on a separate line or after the name-value pairs if you desire.

Default settings for Perl::Critic itself can be set before the first named block. For example, putting any or all of these at the top of your configuration file will set the default value for the corresponding Perl::Critic constructor argument. 

    severity  = 3                                     #Integer from 1 to 5
    only      = 1                                     #Zero or One
    force     = 0                                     #Zero or One
    verbose   = 4                                     #Integer or format spec
    top       = 50                                    #A positive integer
    theme     = risky + (pbp * security) - cosmetic   #A theme expression
    include   = NamingConventions ClassHierarchies    #Space-delimited list
    exclude   = Variables  Modules::RequirePackage    #Space-delimited list
    color     = 1                                     #Zero or One

The remainder of the configuration file is a series of blocks like this: 

    [Perl::Critic::Policy::Category::PolicyName]
    severity = 1
    set_themes = foo bar
    add_themes = baz
    arg1 = value1
    arg2 = value2

Perl::Critic::Policy::Category::PolicyName is the full name of a module that implements the policy. The Policy modules distributed with Perl::Critic have been grouped into categories according to the table of contents in Damian Conway's book Perl Best Practices. For brevity, you can omit the 'Perl::Critic::Policy' part of the module name.

severity is the level of importance you wish to assign to the Policy. All Policy modules are defined with a default severity value ranging from 1 (least severe) to 5 (most severe). However, you may disagree with the default severity and choose to give it a higher or lower severity, based on your own coding philosophy.

The remaining key-value pairs are configuration parameters that will be passed into the constructor of that Policy. The constructors for most Policy modules do not support arguments, and those that do should have reasonable defaults. See the documentation on the appropriate Policy module for more details.

Instead of redefining the severity for a given Policy, you can completely disable a Policy by prepending a '-' to the name of the module in your configuration file. In this manner, the Policy will never be loaded, regardless of the -severity given to the Perl::Critic::Config constructor.

A simple configuration might look like this: 

    #--------------------------------------------------------------
    # I think these are really important, so always load them

    [TestingAndDebugging::RequireUseStrict]
    severity = 5

    [TestingAndDebugging::RequireUseWarnings]
    severity = 5

    #--------------------------------------------------------------
    # I think these are less important, so only load when asked

    [Variables::ProhibitPackageVars]
    severity = 2

    [ControlStructures::ProhibitPostfixControls]
    allow = if unless  #My custom configuration
    severity = 2

    #--------------------------------------------------------------
    # Give these policies a custom theme.  I can activate just
    # these policies by saying (-theme => 'larry + curly')

    [Modules::RequireFilenameMatchesPackage]
    add_themes = larry

    [TestingAndDebugging::RequireTestLables]
    add_themes = curly moe

    #--------------------------------------------------------------
    # I do not agree with these at all, so never load them

    [-NamingConventions::ProhibitMixedCaseVars]
    [-NamingConventions::ProhibitMixedCaseSubs]

    #--------------------------------------------------------------
    # For all other Policies, I accept the default severity, theme
    # and other parameters, so no additional configuration is
    # required for them.

For additional configuration examples, see the perlcriticrc file that is included in this t/examples directory of this distribution.

THE POLICIES

A large number of Policy modules are distributed with Perl::Critic. They are described briefly in the companion document Perl::Critic::PolicySummary and in more detail in the individual modules themselves.

POLICY THEMES

Each Policy is defined with one or more "themes". Themes can be used to create arbitrary groups of Policies. They are intended to provide an alternative mechanism for selecting your preferred set of Policies. For example, you may wish disable a certain subset of Policies when analyzing test scripts. Conversely, you may wish to enable only a specific subset of Policies when analyzing modules.

The Policies that ship with Perl::Critic are have been broken into the following themes. This is just our attempt to provide some basic logical groupings. You are free to invent new themes that suit your needs. 

    THEME             DESCRIPTION
    --------------------------------------------------------------------------
    core              All policies that ship with Perl::Critic
    pbp               Policies that come directly from "Perl Best Practices"
    bugs              Policies that that prevent or reveal bugs
    maintenance       Policies that affect the long-term health of the code
    cosmetic          Policies that only have a superficial effect
    complexity        Policies that specificaly relate to code complexity
    security          Policies that relate to security issues
    tests             Policies that are specific to test scripts

Say `perlcritic -list` to get a listing of all available policies and the themes that are associated with each one. You can also change the theme for any Policy in your .perlcriticrc file. See the "CONFIGURATION" section for more information about that.

Using the -theme option, you can combine theme names with mathematical and boolean operators to create an arbitrarily complex expression that represents a custom "set" of Policies. The following operators are supported 

   Operator       Alternative         Meaning
   ----------------------------------------------------------------------------
   *              and                 Intersection
   -              not                 Difference
   +              or                  Union

Operator precedence is the same as that of normal mathematics. You can also use parenthesis to enforce precedence. Here are some examples: 

   Expression                  Meaning
   ----------------------------------------------------------------------------
   pbp * bugs                  All policies that are "pbp" AND "bugs"
   pbp and bugs                Ditto

   bugs + cosmetic             All policies that are "bugs" OR "cosmetic"
   bugs or cosmetic            Ditto

   pbp - cosmetic              All policies that are "pbp" BUT NOT "cosmetic"
   pbp not cosmetic            Ditto

   -maintenance                All policies that are NOT "maintenance"
   not maintenance             Ditto

   (pbp - bugs) * complexity     All policies that are "pbp" BUT NOT "bugs",
                                    AND "complexity"
   (pbp not bugs) and complexity  Ditto

Theme names are case-insensitive. If -theme is set to an empty string, then it is equivalent to the set of all Policies. A theme name that doesn't exist is equivalent to an empty set. Please See http://en.wikipedia.org/wiki/Set for a discussion on set theory.

AUTHOR

Jeffrey Ryan Thalhammer <thaljef@cpan.org>

COPYRIGHT

Copyright (c) 2005-2007 Jeffrey Ryan Thalhammer. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.