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README.mkdn

NAME

Validation::Class - Low-Fat Full-Flavored Data Validation Construction Kit

VERSION

version 5.0.0_01

SYNOPSIS

use MyApp::Validation;


my $input = MyApp::Validation->new(params => $params);


unless ($input->validate('user', 'pass')){
    return $input->errors_to_string;
}


unless ($input->validate_profile('registration')) {
    return $input->errors_to_string;
}

DESCRIPTION

Validation::Class takes a different approach towards data validation, ... it attempts to simplify and centralize data validation rules to ensure DRY (don't repeat yourself) code. The primary intent of this module is to provide a simplistic data modeling/validation framework.

Your validation class can be thought of as your data input firewall which can be used anywhere and is flexible enough in an MVC environment to be used in the Controller and Model alike.

The benefits this approach provides might require you to change your perspective on parameter handling. Typically when designing an application we tend to name parameters arbitrarily with the only purpose being to identify incoming data within a script on a per use-case basis.

To get the most out of Validation::Class you should consider each parameter hitting your application (individually) as a transmission fitting a very specific criteria. Your validation rules will act as filters which will reject or accept and format the transmission for use within your application. Yes, .. almost exactly like a firewall.

A validation class is defined as follows:

package MyApp::Validation;


use Validation::Class;


# a mixin template
mxn 'basic'  => {
    required   => 1
};


# a validation rule
fld 'login'  => {
    label      => 'User Login',
    error      => 'Login invalid.',
    mixin      => 'basic',
    validation => sub {
        my ($self, $this_field, $all_params) = @_;
        return $this_field->{value} eq 'admin' ? 1 : 0;
    }
};


# a validation rule
fld 'password'  => {
    label         => 'User Password',
    error         => 'Password invalid.',
    mixin         => 'basic',
    validation    => sub {
        my ($self, $this_field, $all_params) = @_;
        return $this_field->{value} eq 'pass' ? 1 : 0;
    }
};


# a validation profile
pro 'registration'  => sub {
    my ($self, @args) = shift;
    return $self->validate(qw(
        +name
        +email
        -login
        +password
    ))
};


1;

The fields defined will be used to validate the specified input parameters. You specify the input parameters at instantiation, parameters should take the form of a hashref of key/value pairs. Multi-level (nested) hashrefs are allowed and are inflated/deflated in accordance with the rules of Hash::Flatten. The following is an example on using your validate class to validate input in various scenarios:

# web app
package MyApp;


use MyApp::Validation;
use Misc::WebAppFramework;


get '/auth' => sub {
    # get user input parameters
    my $params = shift;


    # initialize validation class and set input parameters
    my $rules = MyApp::Validation->new(params => $params);


    unless ($rules->validate('login', 'password')) {


        # print errors to browser unless validation is successful
        return $rules->errors_to_string;


    }


    return 'you have authenticated';
};

BUILDING A VALIDATION CLASS

package MyApp::Validation;


use Validation::Class;


# a validation rule template
mixin 'basic'  => {
    required   => 1,
    min_length => 1,
    max_length => 255,
    filters    => ['lowercase', 'alphanumeric']
};


# a validation rule
field 'user.login'  => {
    mixin      => 'basic',
    label      => 'user login',
    error      => 'login invalid',
    validation => sub {
        my ($self, $this, $fields) = @_;
        return $this->{value} eq 'admin' ? 1 : 0;
    }
};


# a validation rule
field 'user.password'  => {
    mixin         => 'basic',
    label         => 'user login',
    error         => 'login invalid',
    validation    => sub {
        my ($self, $this, $fields) = @_;
        return $this->{value} eq 'pass' ? 1 : 0;
    }
};


1;

THE MIXIN KEYWORD

The mixin keyword (or mxn) creates a validation rules template that can be applied to any field using the mixin directive.

package MyApp::Validation;
use Validation::Class;


mixin 'constrain' => {
    required   => 1,
    min_length => 1,
    max_length => 255,
    ...
};


# e.g.
field 'login' => {
    mixin => 'constrain',
    ...
};

THE FILTER KEYWORD

The filter keyword (or flt) creates custom filters to be used in your field definitions.

package MyApp::Validation;
use Validation::Class;


filter 'usa_telephone_number_converter' => sub {
    $_[0] =~ s/\D//g;
    my ($ac, $pre, $num) = $_[0] =~ /(\d{3})(\d{3})(\d{4})/;
    $_[0] = "($ac) $pre-$num";
};


# e.g.
field 'my_telephone' => {
    filter => ['trim', 'usa_telephone_number_converter'],
    ...
};

THE DIRECTIVE KEYWORD

The directive keyword (or dir) creates custom validator directives to be used in your field definitions. The routine is passed two parameters, the value of directive and the value of the field the validator is being processed against. The validator should return true or false.

package MyApp::Validation;
use Validation::Class;


directive 'between' => sub {
    my ($directive, $value, $field, $class) = @_;
    my ($min, $max) = split /\-/, $directive;
    unless ($value > $min && $value < $max) {
        my $handle = $field->{label} || $field->{name};
        $class->error($field, "$handle must be between $directive");
        return 0;
    }
    return 1;
};


# e.g.
field 'hours' => {
    between => '00-24',
    ...
};

THE FIELD KEYWORD

The field keyword (or fld) creates a validation block and defines validation rules for reuse in code. The field keyword should correspond with the parameter name expected to be passed to your validation class.

package MyApp::Validation;
use Validation::Class;


field 'login' => {
    required   => 1,
    min_length => 1,
    max_length => 255,
    ...
};

The field keyword takes two arguments, the field name and a hashref of key/values pairs.

THE PROFILE KEYWORD

The profile keyword (or pro) stores a validation profile (coderef) which as in the traditional use of the term is a sequence of validation routines that validate data relevant to a specific action. The profile keyword takes a name and coderef as arguments.

package MyApp::Validation;
use Validation::Class;


profile 'app_signup' => sub {


    my ($self, @args) = @_;


    return $self->validate(qw(
        +name
        +email
        +email_confirmation
        -login
        +password
        +password_confirmation
    ));


};


package main;


my $val = MyApp::Validation->new(params => $params);


unless ($val->validate_profile('app_signup')) {
    die $val->errors_to_string;
}

The field keyword takes two arguments, the field name and a hashref of key/values pairs.

FILTERING INCOMING DATA

Validation::Class supports pre/post filtering but is configured to pre-filter incoming data. This means that based upon the filtering options supplied within the individual fields, filtering will happen before validation (technically at instantiation and again just before validation). As expected, this is configurable via the filtering attribute.

A WORD OF CAUTION: Validation::Class is configured to pre-filter incoming data which boosts application security and is best used with passive filtering (e.g. converting character case - filtering which only alters the input in predictable ways), versus aggressive filtering (e.g. formatting a telephone number) which completely and permanently changes the incoming data ... so much so that if the validation still fails ... errors that are reported may not match the data that was submitted.

If you're sure you'd rather employ aggressive filtering, I suggest setting the filtering attribute to 'post' for post-filtering or setting it to null and applying the filters manually by calling the apply_filters() method.

AUTO-SERIALIZATION/DESERIALIZATION

Validation::Class supports automatic serialization and deserialization of parameters with complex data structures which means that you can set a parameter as an arrayref or hashref of nested data structures and validate against them, likewise you can set a parameters using parameter names which are serialized string representations of the keys within the complex structure you wish to set and validate against. The serialization rules are as documented in Hash::Flatten.

The following is an example of that:

my $params = {
    user => {
        login => 'admin',
        password => 'pass'
    }
};


my $rules = MyApp::Validation->new(params => $params);


# or


my $params = {
    'user.login' => 'admin',
    'user.password' => 'pass'
};


my $rules = MyApp::Validation->new(params => $params);


# field definition using field('user.login', ...)
# and field('user.password', ...) will match against the parameters above


# after filtering, validation, etc ... return your params as a hashref if
# needed


my $params = $rules->get_params_hash;

SEPARATION OF CONCERNS

For larger applications where a single validation class might become cluttered and inefficient, Validation::Class comes equipped to help you separate your validation rules into separate classes.

The idea is that you'll end up with a main validation class (most likely empty) that will simply serve as your point of entry into your relative (child) classes. The following is an example of this:

package MyVal::User;
use Validation::Class;


field name => { ... };
field email => { ... };
field login => { ... };
field password => { ... };


package MyVal::Profile;
use Validation::Class;


field age => { ... };
field sex => { ... };
field birthday => { ... };


package MyVal;
use Validation::Class;


load { classes => 1 };


package main;


my $rules = MyVal->new(params => $params);
my $user = $rules->class('user');
my $profile = $rules->class('profile');


...


1;

DEFAULT FIELD/MIXIN DIRECTIVES

package MyApp::Validation;
use Validation::Class;


# a validation template
mixin '...'  => {
    # mixin directives here
    ...
};


# a validation rule
field '...'  => {
    # field directives here
    ...
};


1;

When building a validation class, the first encountered and arguably two most important keyword functions are field() and mixin(), which are used to declare their respective properties. A mixin() declares a validation template where its properties are intended to be copied within field() declarations which declares validation rules, filters and other properties.

Both the field() and mixin() declarations/functions require two parameters, the first being a name, used to identify the declaration and to be matched against incoming input parameters and the second being a hashref of key/value pairs. The key(s) within a declaration are commonly referred to as directives.

The following is a list of default directives which can be used in field/mixin declarations:

alias

The alias directive is useful when many different parameters with different names can be validated using a single rule. E.g. The paging parameters in a webapp may take on different names but require the same validation.

# the alias directive
field 'pager'  => {
    alias => ['page_user_list', 'page_other_list']
    ...
};

default

The default directive is used as a default value for a field to be used when a matching parameter is not present.

# the default directive
field 'quantity'  => {
    default => 1,
    ...
};

error/errors

The error/errors directive is used to replace the system generated error messages when a particular field doesn't validate. If a field fails multiple directives, multiple errors will be generated for the same field. This may not be desirable, the error directive overrides this behavior and only the specified error is registered and displayed.

# the error(s) directive
field 'foobar'  => {
    errors => 'Foobar failed processing, Wtf?',
    ...
};

filtering

The filtering directive is used to control when field filters are applied. The default recognized values are pre/post. A value of 'pre' instructs the validation class to apply the field's filters at instantiation and before validation whereas a value of 'post' instructs the validation class to apply the field's filters after validation. Alternatively, a value of undef or '' will bypass filtering altogether.

# the filtering directive
field 'foobar'  => {
    filtering => 'post',
    ...
};

label

The label directive is used as a user-friendly reference when the field name is a serialized hash key or just plain ugly.

# the label directive
field 'hashref.foo.bar'  => {
    label => 'Foo Bar',
    ...
};

mixin

The mixin directive is used to create a template of directives to be applied to other fields.

mixin 'ID' => {
    required => 1,
    min_length => 1,
    max_length => 11
};

# the mixin directive
field 'user.id'  => {
    mixin => 'ID',
    ...
};

mixin_field

The mixin directive is used to copy all directives from an existing field except for the name, label, and validation directives.

# the mixin_field directive
field 'foobar'  => {
    label => 'Foo Bar',
    required => 1
};


field 'barbaz'  => {
    mixin_field => 'foobar',
    label => 'Bar Baz',
    ...
};

name

The name directive is used internally and cannot be changed.

# the name directive
field 'thename'  => {
    ...
};

required

The required directive is an important directive but can be misunderstood. The required directive is used to ensure the submitted parameter exists and has a value. If the parameter is never submitted, the directive is effectively skipped. This directive can be thought of as the "must-have-a-value-if-exists" directive.

# the required directive
field 'foobar'  => {
    required => 1,
    ...
};


# fail
my $rules = MyApp::Validation->new(params => {  });
$rules->validate('foobar');


# fail
my $rules = MyApp::Validation->new(params => { foobar => '' });
$rules->validate('foobar');


# pass
my $rules = MyApp::Validation->new(params => {  foobar => 'Nice' });
$rules->validate('foobar');

See the toggle functionality within the validate() method. This method allows you to temporarily alter whether a field is required or not.

validation

The validation directive is a coderef used add additional custom validation to the field. The coderef must return true (to pass) or false (to fail). Custom error messages can be set from within the coderef so make sure they are set based on appropriate logic as the registration of error message are not contingent on the success or failure of the routine.

# the validation directive
field 'login'  => {
    validation => sub {
        my ($self, $this_field, $all_params) = @_;
        return 0 unless $this_field->{value};
        return $this_field->{value} eq 'admin' ? 1 : 0;
    },
    ...
};

value

The value directive is used internally to store the field's matching parameter's value. This value can be set in the definition but SHOULD NOT be used as a default value unless you're sure no parameter will overwrite it during run-time. If you need to set a default value, see the default directive.

# the value directive
field 'quantity'  => {
    value => 1,
    ...
};

DEFAULT FIELD/MIXIN FILTER DIRECTIVES

filters

The filters directive is used to correct, alter and/or format the values of the matching input parameter. Note: Filtering is applied before validation. The filter directive can have multiple filters (even a coderef) in the form of an arrayref of values.

# the filter(s) directive
field 'text'  => {
    filters => [qw/trim strip/ => sub {
        $_[0] =~ s/\D//g;
    }],
    ...
};

The following is a list of default filters that may be used with the filter directive:

alpha

The alpha filter removes all non-Alphabetic characters from the field's value.

field 'foobar'  => {
    filter => 'alpha',
};

alphanumeric

The alpha filter removes all non-Alphabetic and non-Numeric characters from the field's value.

field 'foobar'  => {
    filter => 'alphanumeric',
};

capitalize

The capitalize filter attempts to capitalize the first word in each sentence, where sentences are separated by a period and space, within the field's value.

field 'foobar'  => {
    filter => 'capitalize',
};

decimal

The decimal filter removes all non-decimal-based characters from the field's value. Allows only: decimal, comma, and numbers.

field 'foobar'  => {
    filter => 'decimal',
};

numeric

The numeric filter removes all non-numeric characters from the field's value.

field 'foobar'  => {
    filter => 'numeric',
};

strip

As with the trim filter the strip filter removes leading and trailing whitespaces from the field's value and additionally removes multiple whitespaces from between the values characters.

field 'foobar'  => {
    filter => 'strip',
};

titlecase

The titlecase filter converts the field's value to titlecase by capitalizing the first letter of each word.

field 'foobar'  => {
    filter => 'titlecase',
};

trim

The trim filter removes leading and trailing whitespace from the field's value.

field 'foobar'  => {
    filter => 'trim',
};

uppercase

The uppercase filter converts the field's value to uppercase.

field 'foobar'  => {
    filter => 'uppercase',
};

DEFAULT FIELD/MIXIN VALIDATOR DIRECTIVES

package MyApp::Validation;


use Validation::Class;


# a validation rule with validator directives
field 'telephone_number'  => {
    length => 14,
    pattern => '(###) ###-####',
    ...
};


1;

Validator directives are special directives with associated validation code that is used to validate common use cases such as "checking the length of a parameter", etc.

The following is a list of the default validators which can be used in field/mixin declarations:

between

# the between directive
field 'foobar'  => {
    between => '1-5',
    ...
};

depends_on

# the depends_on directive
field 'change_password'  => {
    depends_on => ['password', 'password_confirm'],
    ...
};

length

# the length directive
field 'foobar'  => {
    length => 20,
    ...
};

matches

# the matches directive
field 'this_field'  => {
    matches => 'another_field',
    ...
};

max_alpha

# the max_alpha directive
field 'password'  => {
    max_alpha => 30,
    ...
};

max_digits

# the max_digits directive
field 'password'  => {
    max_digits => 5,
    ...
};

max_length

# the max_length directive
field 'foobar'  => {
    max_length => '...',
    ...
};

max_sum

# the max_sum directive
field 'vacation_days'  => {
    max_sum => 5,
    ...
};

max_symbols

# the max_symbols directive
field 'password'  => {
    max_symbols => 1,
    ...
};

min_alpha

# the min_alpha directive
field 'password'  => {
    min_alpha => 2,
    ...
};

min_digits

# the min_digits directive
field 'password'  => {
    min_digits => 1,
    ...
};

min_length

# the min_length directive
field 'foobar'  => {
    min_length => '...',
    ...
};

min_sum

# the min_sum directive
field 'vacation_days'  => {
    min_sum => 0,
    ...
};

min_symbols

# the min_symbols directive
field 'password'  => {
    min_symbols => 0,
    ...
};

options

# the options directive
field 'status'  => {
    options => 'Active, Inactive',
    ...
};

pattern

# the pattern directive
field 'telephone'  => {
    # simple pattern
    pattern => '### ###-####',
    ...
};


field 'country_code'  => {
    # simple pattern
    pattern => 'XX',
    filter  => 'uppercase'
    ...
};


field 'complex'  => {
    # regex pattern
    pattern => qr/[0-9]+\,\s\.\.\./,
    ...
};

THE VALIDATION CLASS

The following is an example of how to use your constructed validation class in other code, .e.g. Web App Controller, etc.

use MyApp::Validation;


my $input = MyApp::Validation->new(params => $params);
unless ($input->validate('field1','field2')){
    return $input->errors_to_string;
}

Feeling lazy? Have your validation class automatically find the appropriate fields to validate against (params must match field names).

use MyApp::Validation;


my $input = MyApp::Validation->new(params => $params);
unless ($input->validate){
    return $input->errors_to_string;
}

You can define an alias to automatically map a parameter to a validation field whereby a field definition will have an alias attribute containing an arrayref of alternate parameters that can be matched against passed-in parameters.

package MyApp::Validation;


field 'foo.bar' => {
    ...,
    alias => [
        'foo',
        'bar',
        'baz',
        'bax'
    ]
};

use MyApp::Validation;


my  $input = MyApp::Validation->new(params => { foo => 1 });
unless ($input->validate(){
    return $input->errors_to_string;
}

new

The new method instantiates and returns an instance of your validation class.

use MyApp::Validation;


my $input = MyApp::Validation->new;
$input->params($params);
...


my $input = MyApp::Validation->new(params => $params);
...

VALIDATION CLASS ATTRIBUTES

ignore_unknown

The ignore_unknown boolean determines whether your application will live or die upon encountering unregistered field directives during validation. This is off (0) by default, attempts to validate unknown fields WILL cause the program to die.

my $self = MyApp::Validation->new(params => $params, ignore_unknown => 1);
$self->ignore_unknown(1);
...

fields

The fields attribute returns a hashref of defined fields, filtered and merged with their parameter counterparts.

my $self = MyApp::Validation->new(fields => $fields);
my $fields = $self->fields();
...

filtering

The filtering attribute (by default set to 'pre') controls when incoming data is filtered. Setting this attribute to 'post' will defer filtering until after validation which allows any errors messages to report errors based on the unaltered data. Alternatively, setting the filtering attribute to '' or undef will bypass all filtering unless explicitly defined at the field-level.

my $self = MyApp::Validation->new(filtering => 'post');
$self->validate();
...

filters

The filters attribute returns a hashref of pre-defined filter definitions.

my $filters = $self->filters();
...

hash_inflator

The hash_inflator value determines how the hash serializer (inflation/deflation) behaves. The value must be a hashref of "OPTIONS" in Hash::Flatten options. Purely for the sake of consistency, you can use lowercase keys (with underscores) which will be converted to camel-cased keys before passed to the serializer.

my $self = MyApp::Validation->new(
    hash_inflator => {
        hash_delimiter => '/',
        array_delimiter => '//'
    }
);
...

mixins

The mixins attribute returns a hashref of defined validation templates.

my $mixins = $self->mixins();
...

params

The params attribute gets/sets the parameters to be validated.

my $input = {
    ...
};


my $self = MyApp::Validation->new(params => $input);


$self->params($input);
my $params = $self->params();


...

report_unknown

The report_unknown boolean determines whether your application will report unregistered fields as class-level errors upon encountering unregistered field directives during validation. This is off (0) by default, attempts to validate unknown fields will NOT be registered as class-level variables.

my $self = MyApp::Validation->new(params => $params,
ignore_unknown => 1, report_unknown => 1);
$self->report_unknown(1);
...

stashed

The stashed attribute represents a list of field names stored to be used in validation later. If the stashed attribute contains a list you can omit arguments to the validate method.

$self->stashed([qw/this that .../]);

VALIDATION CLASS METHODS

apply_filters

The apply_filters method (usually called automatically based on the filtering attribute) can be used to run the currently defined parameters through the filters defined in the fields.

my $rules = MyVal->new(filtering => '', params => $params);


if ($rules->validate) {
    $rules->apply_filters;
}
else {
    print $rules->errors_to_string;
    # print errors on unaltered parameters
}

class

The class method returns a new initialize child validation class under the namespace of the calling class that issued the load_classes() method call. Existing parameters and configuration options are passed to the child class's constructor. All attributes can be easily overwritten using the attribute's accessors on the child class. Also, you may prevent/override arguments from being copy to the new child class object by supplying the them as arguments to this method.

The class method is also quite handy in that it will detect parameters that are prefixed with the name of the class being fetched, and adjust the matching rule (if any) to allow validation to occur.

package MyVal;
use Validation::Class;


load {
    classes => 1 # load child classes e.g. MyVal::*
};


package main;


my $rules = MyVal->new(params => $params);


my $kid1 = $rules->class('Child'); # loads MyVal::Child;
my $kid2 = $rules->class('StepChild'); # loads MyVal::StepChild;


my $kid3 = $rules->class('child'); # loads MyVal::Child;
my $kid4 = $rules->class('step_child'); # loads MyVal::StepChild;


# WITHOUT COPYING PARAMS FROM MyVal
my $kid5 = $rules->class('child', params => {}); # .. etc


1;

clear_queue

The clear_queue method resets the queue container, see the queue method for more information on queuing fields to be validated. The clear_queue method has yet another useful behavior in that it can assign the values of the queued parameters to the list it is passed, where the values are assigned in the same order queued.

my $rules = MyVal->new(params => $params);


$rules->queue(qw(name +email +login +password));


unless ($rules->validate) {
    return $rules->errors_to_string;
}


$rules->clear_queue(my($name, $email));


1;

clone

The clone method is used to create new fields (rules) from existing fields on-the-fly. This is useful when you have a variable number of parameters being validated that can share existing validation rules. E.g., a web-form on a user's profile page may have dynamically created input boxes for the person's phone numbers allowing the user to add additional parameters to the web-form as needed, in that case as opposed to having multiple validation rules hardcoded for each parameter, you could hardcode one single rule and clone the rule at run-time.

package MyVal;
use Validation::Class;


field phone => { required => 1 };


package main;


my $rules = MyVal->new(params => $params);


# clone phone rule at run-time to validate dynamically created parameters
$rules->clone('phone', 'phone2', { label => 'Other Phone', required => 0 });
$rules->clone('phone', 'phone3', { label => 'Third Phone', required => 0 });
$rules->clone('phone', 'phone4', { label => 'Forth Phone', required => 0 });


$rules->validate(qw/phone phone2 phone3 phone4/);


1;

error

The error method is used to set and/or retrieve errors encountered during validation. The error method with no parameters returns the error message object which is an arrayref of error messages stored at class-level.

# return all errors encountered/set as an arrayref
return $self->error();


# return all errors specific to the specified field (at the field-level)
# as an arrayref
return $self->error('some_field_name');


# set an error specific to the specified field (at the field-level)
# using the field object (hashref not field name)
$self->error($field_object, "i am your error message");

unless ($self->validate) {
    my $fields = $self->error();
}

error_count

The error_count method returns the total number of error encountered from the last validation call.

return $self->error_count();


unless ($self->validate) {
    print "Found ". $self->error_count ." Errors";
}

error_fields

The error_fields method returns a hashref of fields whose value is an arrayref of error messages.

unless ($self->validate) {
    my $bad_fields = $self->error_fields();
}

errors_to_string

The errors_to_string method stringifies the error arrayref object using the specified delimiter or ', ' by default.

return $self->errors_to_string();
return $self->errors_to_string("<br/>\n");


unless ($self->validate) {
    return $self->errors_to_string;
}

get_errors

The get_errors method returns the list of class-level error set on the current class.

my @errors = $self->get_errors();

get_params

The get_params method returns the values (in list form) of the parameters specified.

if ($self->validate) {
    my $name_a = $self->get_params('name');
    my ($name_b, $email, $login, $password) =
        $self->get_params(qw/name email login password/);


    # you should note that if the params dont exist they will return undef
    # ... meaning you should check that it exists before checking its value
    # e.g.


    if (defined $name) {
        if ($name eq '') {
            print 'name parameter was passed but was empty';
        }
    }
    else {
        print 'name parameter was never submitted';
    }
}

get_params_hash

If your fields and parameters are designed with complex hash structures, the get_params_hash method returns the deserialized hashref of specified parameters based on the the default or custom configuration of the hash serializer Hash::Flatten.

my $params = {
    'user.login' => 'member',
    'user.password' => 'abc123456'
};


if ($self->validate(keys %$params)) {
    my $params = $self->get_params_hash;
    print $params->{user}->{login};
}

load

The load method provides a more structured and aesthetically pleasing interface for configuring the current class.

package MyVal;
use Validation::Class;


load {
    classes => 1, # same as above
    plugins => [
        ...
    ]
};


1;

load_classes

The load_classes method uses Module::Find to load child classes for convenient access through the class() method. Existing parameters and configuration options are passed to the child class's constructor. All attributes can be easily overwritten using the attribute's accessors on the child class.

package MyVal;
use Validation::Class;


__PACKAGE__->load_classes;


# or


load {
    classes => 1 # same as above
};


1;

load_plugins

The load_plugins method is used to load plugins that support Validation::Class. A Validation::Class plugin is little more than a Role (Moose::Role) that extends the Validation::Class core. As usual, an official Validation::Class plugin can be referred to using shorthand while custom plugins are called by prefixing a plus symbol to the fully-qualified plugin name. Learn more about plugins at Validation::Class::Plugins.

package MyVal;
use Validation::Class;


__PACKAGE__->load_plugins('SuperX');
# loads Validation::Class::Plugin::SuperX


__PACKAGE__->load_plugins('+MyApp::Validation::Plugin::SuperY');


# or


load {
    plugins => [
        'SuperX',
        '+MyApp::Validation::Plugin::SuperY'
    ]
}; # same as above


1;

param

The param method returns a single parameter by name.

if ($self->param('chng_pass')) {
    $self->validate('password_confirmation');
}

queue

The queue method is a convenience method used specifically to append the stashed attribute allowing you to queue field to be validated. This method also allows you to set fields that must always be validated.

# conditional validation flow WITHOUT the queue method
# imagine a user profile update action


my $rules = MyApp::Validation->new(params => $params);
my @fields = qw/name login/;


push @fields, 'email_confirm' if $rules->param('chg_email');
push @fields, 'password_confirm' if $rules->param('chg_pass');


... if $rules->validate(@fields);


# conditional validation WITH the queue method


my $rules = MyApp::Validation->new(params => $params);


$rules->queue(qw/name login/);
$rules->queue(qw/email_confirm/) if $rules->param('chg_email');
$rules->queue(qw/password_confirm/) if $rules->param('chg_pass');


... if $rules->validate();


# set fields that must ALWAYS be validated
# imagine a simple REST server


my $rules = MyApp::Validation->new(params => $params);


$rules->queue(qw/login password/);


if ($request eq '/resource/:id') {


    if ($rules->validate('id')) {


        # validated login, password and id
        ...
    }
}

reset

The reset method clears all errors, fields and stashed field names, both at the class and individual field levels.

$self->reset();

reset_errors

The reset_errors method clears all errors, both at the class and individual field levels. This method is called automatically every time the validate() method is triggered.

$self->reset_errors();

reset_fields

The reset_fields method clears all errors and field values, both at the class and individual field levels. This method is executed automatically at instantiation.

$self->reset_fields();

sanitize

The sanitize method executes a set of routines that reset the parameter environment filtering any parameters present. This method is executed automatically at instantiation and validation.

$self->sanitize();

set_errors

The set_errors method pushes its arguments (error messages) onto the class-level error stack of the current class.

my $count = $self->set_errors('Oops', 'OMG', 'WTF');

set_params_hash

Depending on how parameters are being input into your application, if your input parameters are already complex hash structures, The set_params_hash method will set and return the serialized version of your hashref based on the the default or custom configuration of the hash serializer Hash::Flatten.

my $params = {
    user => {
        login => 'member',
        password => 'abc123456'
    }
};


my $serialized_params = $self->set_params_hash($params);

stash

The stash method provides a container for context/instance specific information. The stash is particularly useful when custom validation routines require insight into context/instance specific operations.

package MyApp::Validation;


use Validation::Class;


fld 'email' => {
    validation => sub {
        my $db = shift->stash->{database};
        my $this = shift;


        return $db->find('email' => $this->{value}) ? 0 : 1 ; # email exists
    }
};


package main;


$self->stash( { database => $dbix_object } );
$self->stash( ftp => $net_ftp, database => $dbix_object );


...

validate

The validate method returns true/false depending on whether all specified fields passed validation checks.

use MyApp::Validation;


my $input = MyApp::Validation->new(params => $params);


# validate specific fields
unless ($input->validate('field1','field2')){
    return $input->errors_to_string;
}


# validate fields based on a regex pattern
unless ($input->validate(qr/^field(\d+)?/)){
    return $input->errors_to_string;
}


# validate existing parameters, if no parameters exist,
# validate all fields ... which will return true unless field(s) exist
# with a required directive
unless ($input->validate()){
    return $input->errors_to_string;
}


# validate all fields period, obviously
unless ($input->validate(keys %{$input->fields})){
    return $input->errors_to_string;
}


# validate specific parameters (by name) after mapping them to other fields
my $parameter_map = {
    user => 'hey_im_not_named_login',
    pass => 'password_is_that_really_you'
};
unless ($input->validate($parameter_map)){
    return $input->errors_to_string;
}

Another cool trick the validate() method can perform is the ability to temporarily alter whether a field is required or not during run-time. This functionality is often referred to as the toggle function.

This method is important when you define a field (or two or three) as required or non and want to change that per validation. This is done by calling the validate() method with a list of fields to be validated and prefixing the target fields with a plus or minus as follows:

use MyApp::Validation;


my $input = MyApp::Validation->new(params => $params);


# validate specific fields, force name, email and phone to be required
# regardless of the field definitions directives ... and force the age, sex
# and birthday to be optional


my @spec = qw(+name +email +phone -age -sex -birthday);


unless ($input->validate(@spec)){
    return $input->errors_to_string;
}

validate_profile

The validate_profile method executes a stored validation profile, it requires a profile name and can be passed additional parameters which get forwarded into the profile routine in the order received.

unless ($self->validate_profile('password_change')) {
    die $self->errors_to_string;
}


unless ($self->validate_profile('email_change', $dbi_handle)) {
    die $self->errors_to_string;
}

AUTHOR

Al Newkirk awncorp@cpan.org

COPYRIGHT AND LICENSE

This software is copyright (c) 2011 by awncorp.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

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