NAME¶
HTML::FormFu::Constraint - Constrain User Input
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
DESCRIPTION¶
User input is processed in the following order:
- Filters
- Constraints
- Inflators
- Validators
- Transformers
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.
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.
See "FORM LOGIC AND VALIDATION" in HTML::FormFu for further details.
METHODS¶
type¶
Returns the "type" argument originally used to create the constraint.
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.
only_on_reps¶
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.
Not available for the constraints listed in "Unsupported Constraints"
in HTML::FormFu::Element::Repeatable.
message¶
Arguments: $string
Set the message which will be displayed if the constraint fails.
message_xml¶
Arguments: $string
Variant of "message" which ensures the value won't be XML-escaped.
message_loc¶
Arguments: $string
Variant of "message" which uses localize to create the message.
localize_args¶
Provide arguments that should be passed to localize to replace "[_1]",
"[_2]", etc. in the localized string.
force_errors¶
See "force_errors" in HTML::FormFu for details.
parent¶
Returns the field object that the constraint is associated with.
Returns the HTML::FormFu object that the constraint's field is attached to.
name¶
Shorthand for "$constraint->parent->name"
when¶
Defines a condition for the constraint. Only when the condition is fullfilled
the constraint will be applied.
This method expects a hashref.
The "field" or "callback" must be supplied, all other fields
are optional.
If "value" or "values" is not supplied, the constraint will
pass if the named field's value is true.
The following keys are supported:
- field
- 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.
- fields
- 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.
- any_field
- 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.
- value
- Expected value in the form field 'field'
- values
- Array of multiple values, one must match to fullfill the condition
- not
- Inverts the when condition - value(s) must not match
- 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:
- 1.
- $params (hashref of all submitted parameters)
- 2.
- $constraint (the Constraint object)
EXPERIMENTAL METHODS¶
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 "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.
CORE CONSTRAINTS¶
- HTML::FormFu::Constraint::AllOrNone
- HTML::FormFu::Constraint::ASCII
- HTML::FormFu::Constraint::AutoSet
- HTML::FormFu::Constraint::Bool
- HTML::FormFu::Constraint::Callback
- HTML::FormFu::Constraint::CallbackOnce
- HTML::FormFu::Constraint::DateTime
- HTML::FormFu::Constraint::DependOn
- HTML::FormFu::Constraint::Email
- HTML::FormFu::Constraint::Equal
- HTML::FormFu::Constraint::File
- HTML::FormFu::Constraint::File::MIME
- HTML::FormFu::Constraint::File::MaxSize
- HTML::FormFu::Constraint::File::MinSize
- HTML::FormFu::Constraint::File::Size
- HTML::FormFu::Constraint::Integer
- HTML::FormFu::Constraint::Length
- HTML::FormFu::Constraint::MaxLength
- HTML::FormFu::Constraint::MaxRange
- HTML::FormFu::Constraint::MinLength
- HTML::FormFu::Constraint::MinRange
- HTML::FormFu::Constraint::MinMaxFields
- HTML::FormFu::Constraint::Number
- HTML::FormFu::Constraint::Printable
- HTML::FormFu::Constraint::Range
- HTML::FormFu::Constraint::Regex
- HTML::FormFu::Constraint::Required
- HTML::FormFu::Constraint::Set
- HTML::FormFu::Constraint::SingleValue
- HTML::FormFu::Constraint::Word
NON-CORE CONSTRAINTS AVAILABLE ON CPAN¶
- HTML::FormFu::Constraint::reCAPTCHA
CAVEATS¶
See "Unsupported Constraints" in HTML::FormFu::Element::Repeatable for
a list of constraints that won't work within
HTML::FormFu::Element::Repeatable.
AUTHOR¶
Carl Franks, "cfranks@cpan.org"
Based on the original source code of HTML::Widget::Constraint, by Sebastian
Riedel, "sri@oook.de".
LICENSE¶
This library is free software, you can redistribute it and/or modify it under
the same terms as Perl itself.