package HTML::FormFu::Constraint;
use strict;
our $VERSION = '2.03'; # VERSION
use Moose;
use MooseX::Attribute::FormFuChained;
extends 'HTML::FormFu::Processor';
use HTML::FormFu::Exception::Constraint;
use HTML::FormFu::Util qw(
DEBUG_CONSTRAINTS
DEBUG_CONSTRAINTS_WHEN
debug
);
use Clone ();
use List::MoreUtils qw( any );
use Scalar::Util qw( blessed );
use Carp qw( croak );
use List::MoreUtils qw( any all );
use List::Util qw( first );
use Scalar::Util qw( reftype blessed );
has not => ( is => 'rw', traits => ['FormFuChained'] );
has force_errors => ( is => 'rw', traits => ['FormFuChained'] );
has when => ( is => 'rw', traits => ['FormFuChained'] );
has only_on_reps => ( is => 'rw', traits => ['FormFuChained'] );
sub repeatable_repeat {
my ( $self, $repeatable, $new_block ) = @_;
my $block_fields = $new_block->get_fields;
# rename any 'when' fields
{
my $when = $self->when;
if ( my $name = $when->{field} ) {
my $field = $repeatable->get_field_with_original_name( $name,
$block_fields );
if ( defined $field ) {
DEBUG_CONSTRAINTS && debug(
sprintf
"Repeatable renaming constraint 'when{field}' '%s' to '%s'",
$name, $field->nested_name,
);
$when->{field} = $field->nested_name;
}
}
elsif ( my $names = $when->{fields} ) {
for my $name (@$names) {
my $field = $repeatable->get_field_with_original_name( $name,
$block_fields );
if ( defined $field ) {
$when->{field} = $field->nested_name;
}
}
}
}
}
sub pre_process { }
sub process {
my ( $self, $params ) = @_;
return unless $self->_run_this_rep;
my $value = $self->_find_field_value($params);
my @errors;
# check when condition
if ( !$self->_process_when($params) ) {
DEBUG_CONSTRAINTS && debug('fail when() check - skipping constraint');
return;
}
if ( ref $value eq 'ARRAY' ) {
push @errors, eval { $self->constrain_values( $value, $params ) };
if ($@) {
push @errors,
$self->mk_errors( {
pass => 0,
message => $@,
} );
}
}
else {
my $ok = eval { $self->constrain_value( $value, $params ) };
DEBUG_CONSTRAINTS && debug( 'CONSTRAINT RETURN VALUE' => $ok );
DEBUG_CONSTRAINTS && debug( '$@' => $@ );
push @errors,
$self->mk_errors( {
pass => ( $@ || !$ok ) ? 0 : 1,
message => $@,
} );
}
return @errors;
}
sub _run_this_rep {
my ($self) = @_;
my $only_on_reps = $self->only_on_reps
or return 1;
my $current_rep = $self->field->repeatable_count
or return 1;
$only_on_reps = [$only_on_reps]
if ( reftype($only_on_reps) || '' ) ne 'ARRAY';
return first { $current_rep == $_ } @$only_on_reps;
}
sub _find_field_value {
my ( $self, $params ) = @_;
my $value = $self->get_nested_hash_value( $params, $self->nested_name );
my @fields_with_this_name
= @{ $self->form->get_fields( { nested_name => $self->nested_name } ) };
if ( @fields_with_this_name > 1 ) {
my $field = $self->parent;
my $index;
for ( my $i = 0; $i <= $#fields_with_this_name; ++$i ) {
if ( $fields_with_this_name[$i] eq $field ) {
$index = $i;
last;
}
}
croak 'did not find ourself - how can this happen?'
if !defined $index;
if ( ( reftype($value) || '' ) eq 'ARRAY' ) {
$value = $value->[$index];
}
elsif ( $index == 0 ) {
# keep $value
}
else {
undef $value;
}
}
return $value;
}
sub constrain_values {
my ( $self, $values, $params ) = @_;
my @errors;
for my $value (@$values) {
my $ok = eval { $self->constrain_value( $value, $params ) };
DEBUG_CONSTRAINTS && debug( 'CONSTRAINT RETURN VALUE' => $ok );
DEBUG_CONSTRAINTS && debug( '$@' => $@ );
push @errors,
$self->mk_errors( {
pass => ( $@ || !$ok ) ? 0 : 1,
message => $@,
} );
}
return @errors;
}
sub constrain_value {
croak "constrain_value() should be overridden";
}
sub mk_errors {
my ( $self, $args ) = @_;
my $pass = $args->{pass};
my $message = $args->{message};
my @errors;
my $force = $self->force_errors || $self->parent->force_errors;
if ( !$pass || $force ) {
my $error = $self->mk_error($message);
$error->forced(1) if $pass;
push @errors, $error;
}
return @errors;
}
sub mk_error {
my ( $self, $err ) = @_;
if ( !blessed $err || !$err->isa('HTML::FormFu::Exception::Constraint') ) {
$err = HTML::FormFu::Exception::Constraint->new;
}
return $err;
}
sub _process_when {
my ( $self, $params ) = @_;
# returns 1 if when condition is fullfilled or not defined
# returns 0 if when condition is defined and not fullfilled
# If it's a callback, return callback's return value (so 'when'
# condition is met if callback returns a true value)
# get when condition
my $when = $self->when;
return 1 if !defined $when;
# check type of 'when'
croak "Parameter 'when' is not a hash ref" if ref $when ne 'HASH';
# field or callback must be defined
my $when_field = $when->{field};
my $when_fields = $when->{fields};
my $when_any_field = $when->{any_field};
my $when_callback = $when->{callback};
croak
"'field', 'fields', 'any_field' or 'callback' key must be defined in 'when'"
if all { !defined } $when_field, $when_fields, $when_any_field,
$when_callback;
# Callback will be the preferred thing
if ($when_callback) {
## no critic (ProhibitNoStrict);
no strict 'refs';
return $when_callback->( $params, $self );
}
my $any;
my @when_fields_value;
if ($when_any_field) {
croak "'any_field' is set to an empty list" if !@$when_any_field;
$any = 1;
@$when_fields = @$when_any_field;
}
if ($when_fields) {
croak "'fields' is set to an empty list" if !@$when_fields;
for my $name (@$when_fields) {
my $value = $self->get_nested_hash_value( $params, $name );
push @when_fields_value, $value
if defined $value;
}
}
else {
# nothing to constrain if field doesn't exist
my $value = $self->get_nested_hash_value( $params, $when_field );
push @when_fields_value, $value
if defined $value;
}
DEBUG_CONSTRAINTS_WHEN && debug( 'WHEN_FIELDS_VALUES' => \@when_fields_value );
if ( !@when_fields_value ) {
DEBUG_CONSTRAINTS_WHEN
&& debug("No 'when' fields values exist - returning false");
return 0;
}
my @values;
if ( defined( my $value = $when->{value} ) ) {
push @values, $value;
}
elsif ( defined( my $values = $when->{values} ) ) {
push @values, @$values;
}
# determine if condition is fulfilled
my @ok;
if (@values) {
for my $value (@when_fields_value) {
push @ok, any { $value eq $_ } @values;
}
}
else {
for my $value (@when_fields_value) {
push @ok, $value ? 1 : 0;
}
}
DEBUG_CONSTRAINTS_WHEN && debug( "'when' value matches" => \@ok );
my $return
= $any
? any { $when->{not} ? !$_ : $_ } @ok
: all { $when->{not} ? !$_ : $_ } @ok;
DEBUG_CONSTRAINTS_WHEN && debug( "'when' return value" => $return );
return $return;
}
sub fetch_error_message {
my ( $self ) = @_;
my $error = HTML::FormFu::Exception::Constraint->new({
form => $self->form,
parent => $self->parent,
processor => $self,
});
return $error->message;
}
sub clone {
my $self = shift;
my $clone = $self->SUPER::clone(@_);
if ( defined( my $when = $self->when ) ) {
$clone->when( Clone::clone $when );
}
return $clone;
}
__PACKAGE__->meta->make_immutable;
1;
__END__
=head1 NAME
HTML::FormFu::Constraint - Constrain User Input
=head1 VERSION
version 2.03
=head1 SYNOPSIS
---
elements:
- type: Text
name: foo
constraints:
- type: Length
min: 8
when:
field: bar
values: [ 1, 3, 5 ]
- type: Text
name: bar
constraints:
- Integer
- Required
constraints:
- SingleValue
=head1 DESCRIPTION
User input is processed in the following order:
=over
=item L<Filters|HTML::FormFu::Filter>
=item L<Constraints|HTML::FormFu::Constraint>
=item L<Inflators|HTML::FormFu::Inflator>
=item L<Validators|HTML::FormFu::Validator>
=item L<Transformers|HTML::FormFu::Transformer>
=back
See L<HTML::FormFu/"FORM LOGIC AND VALIDATION"> for further details.
L<HTML::FormFu/constraints> can be called on any L<form|HTML::FormFu>,
L<block element|HTML::FormFu::Element::Block> (includes fieldsets) or
L<field element|HTML::FormFu::Role::Element::Field>.
If called on a field element, no C<name> argument should be passed.
If called on a L<form|HTML::FormFu> or
L<block element|HTML::FormFu::Element::Block>, if no C<name> argument is
provided, a new constraint is created for and added to every field on that
form or block.
See L<HTML::FormFu/"FORM LOGIC AND VALIDATION"> for further details.
=head1 METHODS
=head2 type
Returns the C<type> argument originally used to create the constraint.
=head2 not
If true, inverts the results of the constraint - such that input that would
otherwise fail will pass, and vise-versa.
This value is ignored by some constraints - see the documentation for
individual constraints for details.
=head2 only_on_reps
Argument: \@repeatable_count
For constraints added to fields within a
L<Repeatable|HTML::FormFu::Element::Repeatable> element, if C<only_on_reps>
is set, the constraint will only be run for fields whose
L<repeatable_count|HTML::FormFu::Role::Element::Field/repeatable_count>
matches one of these set values.
Not available for the constraints listed in
L<HTML::FormFu::Element::Repeatable/"Unsupported Constraints">.
=head2 message
Arguments: $string
Set the message which will be displayed if the constraint fails.
=head2 message_xml
Arguments: $string
Variant of L</message> which ensures the value won't be XML-escaped.
=head2 message_loc
Arguments: $string
Variant of L</message> which uses L<localize|HTML::FormFu/localize> to
create the message.
=head2 localize_args
Provide arguments that should be passed to L<localize|HTML::FormFu/localize>
to replace C<[_1]>, C<[_2]>, etc. in the localized string.
=head2 force_errors
See L<HTML::FormFu/force_errors> for details.
=head2 parent
Returns the L<field|HTML::FormFu::Role::Element::Field> object that the constraint
is associated with.
=head2 form
Returns the L<HTML::FormFu> object that the constraint's field is attached
to.
=head2 name
Shorthand for C<< $constraint->parent->name >>
=head2 when
Defines a condition for the constraint. Only when the condition is fullfilled
the constraint will be applied.
This method expects a hashref.
The C<field> or C<callback> must be supplied, all other fields are optional.
If C<value> or C<values> is not supplied, the constraint will pass if the
named field's value is true.
The following keys are supported:
=over
=item field
Nested-name of form field that shall be checked against - if C<when->{value}>
is set, the C<when> condition passes if the named field's value matches that,
otherwise the C<when> condition passes if the named field's value is true.
=item fields
Array-ref of nested-names that shall be checked. The C<when> condition passes
if all named-fields' values pass, using the same rules as C<field> above.
=item any_field
Array-ref of nested-names that shall be checked. The C<when> condition passes
if any named-fields' values pass, using the same rules as C<field> above.
=item value
Expected value in the form field 'field'
=item values
Array of multiple values, one must match to fullfill the condition
=item not
Inverts the when condition - value(s) must not match
=item callback
A callback subroutine-reference or fully resolved subroutine name can be
supplied to perform complex checks. An hashref of all parameters is passed
to the callback sub. In this case all other keys are ignored, including not.
You need to return a true value for the constraint to be applied or a false
value to not apply it.
The callback subroutine receives 2 arguments:
=over 8
=item 1
C<$params> (hashref of all submitted parameters)
=item 2
C<$constraint> (the Constraint object)
=back
=back
=head1 EXPERIMENTAL METHODS
=head2 fetch_error_message
Return value: $string
Attempt to return the error message that would be used if this constraint
generated an error.
This will generally be correct for simple constraints with a fixed message or
which use a placeholder from a known value, such as
L<HTML::FormFu::Constraint::Min/min>.
This will generally C<not> return the correct message for constraints which
use L<HTML::FormFu::Role::Constraint::Others/others>, where the field with an
error is not known without actually fully processing a form submission.
=head1 CORE CONSTRAINTS
=over
=item L<HTML::FormFu::Constraint::AllOrNone>
=item L<HTML::FormFu::Constraint::ASCII>
=item L<HTML::FormFu::Constraint::AutoSet>
=item L<HTML::FormFu::Constraint::Bool>
=item L<HTML::FormFu::Constraint::Callback>
=item L<HTML::FormFu::Constraint::CallbackOnce>
=item L<HTML::FormFu::Constraint::DateTime>
=item L<HTML::FormFu::Constraint::DependOn>
=item L<HTML::FormFu::Constraint::Email>
=item L<HTML::FormFu::Constraint::Equal>
=item L<HTML::FormFu::Constraint::File>
=item L<HTML::FormFu::Constraint::File::MIME>
=item L<HTML::FormFu::Constraint::File::MaxSize>
=item L<HTML::FormFu::Constraint::File::MinSize>
=item L<HTML::FormFu::Constraint::File::Size>
=item L<HTML::FormFu::Constraint::Integer>
=item L<HTML::FormFu::Constraint::Length>
=item L<HTML::FormFu::Constraint::MaxLength>
=item L<HTML::FormFu::Constraint::MaxRange>
=item L<HTML::FormFu::Constraint::MinLength>
=item L<HTML::FormFu::Constraint::MinRange>
=item L<HTML::FormFu::Constraint::MinMaxFields>
=item L<HTML::FormFu::Constraint::Number>
=item L<HTML::FormFu::Constraint::Printable>
=item L<HTML::FormFu::Constraint::Range>
=item L<HTML::FormFu::Constraint::Regex>
=item L<HTML::FormFu::Constraint::Required>
=item L<HTML::FormFu::Constraint::Set>
=item L<HTML::FormFu::Constraint::SingleValue>
=item L<HTML::FormFu::Constraint::Word>
=back
=head1 NON-CORE CONSTRAINTS AVAILABLE ON CPAN
=over
=item L<HTML::FormFu::Constraint::reCAPTCHA>
=back
=head1 CAVEATS
See L<HTML::FormFu::Element::Repeatable/"Unsupported Constraints">
for a list of constraints that won't work within
L<HTML::FormFu::Element::Repeatable>.
=head1 AUTHOR
Carl Franks, C<cfranks@cpan.org>
Based on the original source code of L<HTML::Widget::Constraint>, by
Sebastian Riedel, C<sri@oook.de>.
=head1 LICENSE
This library is free software, you can redistribute it and/or modify it under
the same terms as Perl itself.
=cut