HTML::FormFu::Constraint - Constrain User Input
version 2.07
--- 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
User input is processed in the following order:
See "FORM LOGIC AND VALIDATION" in HTML::FormFu for further details.
"constraints" in HTML::FormFu can be called on any form, block element (includes fieldsets) or field element.
If called on a field element, no name argument should be passed.
name
If called on a form or block element, if no name argument is provided, a new constraint is created for and added to every field on that form or block.
Returns the type argument originally used to create the constraint.
type
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.
Argument: \@repeatable_count
For constraints added to fields within a Repeatable element, if only_on_reps is set, the constraint will only be run for fields whose repeatable_count matches one of these set values.
only_on_reps
Not available for the constraints listed in "Unsupported Constraints" in HTML::FormFu::Element::Repeatable.
Arguments: $string
Set the message which will be displayed if the constraint fails.
Variant of "message" which ensures the value won't be XML-escaped.
Variant of "message" which uses localize to create the message.
Provide arguments that should be passed to localize to replace [_1], [_2], etc. in the localized string.
[_1]
[_2]
See "force_errors" in HTML::FormFu for details.
Returns the field object that the constraint is associated with.
Returns the HTML::FormFu object that the constraint's field is attached to.
Shorthand for $constraint->parent->name
$constraint->parent->name
Defines a condition for the constraint. Only when the condition is fulfilled the constraint will be applied.
This method expects a hashref.
The field or callback must be supplied, all other fields are optional.
field
callback
If value or values is not supplied, the constraint will pass if the named field's value is true.
value
values
The following keys are supported:
Nested-name of form field that shall be checked against - if when->{value} is set, the when condition passes if the named field's value matches that, otherwise the when condition passes if the named field's value is true.
when->{value}
when
Array-ref of nested-names that shall be checked. The when condition passes if all named-fields' values pass, using the same rules as field above.
Array-ref of nested-names that shall be checked. The when condition passes if any named-fields' values pass, using the same rules as field above.
Expected value in the form field 'field'
Array of multiple values, one must match to fulfill the condition
Inverts the when condition - value(s) must not match
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.
not
The callback subroutine receives 2 arguments:
$params (hashref of all submitted parameters)
$params
$constraint (the Constraint object)
$constraint
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 "min" in HTML::FormFu::Constraint::Min. This will generally not return the correct message for constraints which use "others" in HTML::FormFu::Role::Constraint::Others, where the field with an error is not known without actually fully processing a form submission.
See "Unsupported Constraints" in HTML::FormFu::Element::Repeatable for a list of constraints that won't work within HTML::FormFu::Element::Repeatable.
Carl Franks, cfranks@cpan.org
cfranks@cpan.org
Based on the original source code of HTML::Widget::Constraint, by Sebastian Riedel, sri@oook.de.
sri@oook.de
This library is free software, you can redistribute it and/or modify it under the same terms as Perl itself.
Carl Franks <cpan@fireartist.com>
This software is copyright (c) 2018 by Carl Franks.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
To install HTML::FormFu, copy and paste the appropriate command in to your terminal.
cpanm
cpanm HTML::FormFu
CPAN shell
perl -MCPAN -e shell install HTML::FormFu
For more information on module installation, please visit the detailed CPAN module installation guide.