NAME

Dancer2::Plugin::FormValidator - neat and easy to start form validation plugin for Dancer2.

VERSION

version 0.31

SYNOPSIS

use Dancer2::Plugin::FormValidator;

post '/form' => sub {
    if (my $valid_hash_ref = validate_form 'form') {
        save_user_input($valid_hash_ref);
        redirect '/success_page';
    }

    redirect '/form';
};

DISCLAIMER

This is alpha version, not stable.

Interfaces may change in future:

  • Template tokens: errors.

  • Roles: Dancer2::Plugin::FormValidator::Role::Extension, Dancer2::Plugin::FormValidator::Role::Validator.

  • Validators.

Won't change:

  • Dsl keywords: validate_form, validator_language, errors.

  • Template tokens: old.

  • Roles: Dancer2::Plugin::FormValidator::Role::Profile, Dancer2::Plugin::FormValidator::Role::HasMessages, Dancer2::Plugin::FormValidator::Role::ProfileHasMessages.

If you like it - add it to your bookmarks. I intend to complete the development by the summer 2022.

Have any ideas? Find this project on github (repo ref is at the bottom). Help is always welcome!

DESCRIPTION

This is micro-framework that provides validation in your Dancer2 application. It consists of dsl's keywords and a set of agreements. It has a set of built-in validators that can be extended by compatible modules (extensions). Also proved runtime switching between languages, so you can show proper error messages to users.

Uses simple and declarative approach to validate forms:

Validator

First, you need to create class which will implements at least one main role: Dancer2::Plugin::FormValidator::Role::HasProfile.

This role requires profile method which should return a HashRef Data::FormValidator accepts:

package App::Http::Validators::RegisterForm {
    use Moo;
    with 'Dancer2::Plugin::FormValidator::Role::Profile';

    sub profile {
        return {
            name  => [qw(required length_min:4 length_max:32)]
            email => [qw(required email)],
        };
    };
}

Application

Then you need to set an form => validator association in config:

set plugins => {
       FormValidator => {
           session => {
               namespace => '_form_validator' # This is required field
           },
           forms   => {
               register_form => 'App::App::Http::Validators::RegisterForm',
           },
       },
   };

Now you can validate POST parameters in your controller:

use Dancer2::Plugin::FormValidator;

post '/register' => sub {
    if (my $valid_hash_ref = validate_form 'register_form') {
        if (login($valid_hash_ref)) {
            redirect '/success_page';
        }
    }

    redirect '/register';
};

get '/register' => sub {
    template 'app/register' => {
        title  => 'Register page',
    };
};

Template

In you template you have access to: $errors - this is HashRef with parameters names as keys and error messages as ArrayRef values and $old - contains old input values.

Template app/register:

<div class="w-3/4 max-w-md bg-white shadow-lg py-4 px-6">
    <form method="post" action="/register">
        <div class="py-2">
            <label class="block font-normal text-gray-400" for="name">
                Name
            </label>
            <input
                    type="text"
                    id="name"
                    name="name"
                    value="<: $old[name] :>"
                    class="border border-2 w-full h-5 px-4 py-5 mt-1 rounded-md
                    hover:outline-none focus:outline-none focus:ring-1 focus:ring-indigo-100"
            >
            <: for $errors[name] -> $error { :>
                <small class="pl-1 text-red-400"><: $error :></small>
            <: } :>
        </div>
        <div class="py-2">
            <label class="block font-normal text-gray-400" for="email">
                Name
            </label>
            <input
                    type="text"
                    id="email"
                    name="email"
                    value="<: $old[email] :>"
                    class="border border-2 w-full h-5 px-4 py-5 mt-1 rounded-md
                    hover:outline-none focus:outline-none focus:ring-1 focus:ring-indigo-100"
            >
            <: for $errors[email] -> $error { :>
                <small class="pl-1 text-red-400"><: $error :></small>
            <: } :>
        </div>
        <button
                type="submit"
                class="mt-4 bg-sky-600 text-white py-2 px-6 rounded-md hover:bg-sky-700"
        >
            Register
        </button>
    </form>
</div>

CONFIGURATION

...
plugins:
    FormValidator:
        session:
            namespace: '_form_validator' # this is required
        messages:
            language: en                 # this is default
            ucfirst: 1                   # this is default
            validators:
                required:
                    en: %s is needed from config
                    de: %s ist erforderlich
                ...
        forms:
            login_form: 'App::Http::Validators::LoginForm'
            support_form: 'App::Http::Validators::SupportForm'
            ...
        extensions:
            upload:
                provider: ...
                ...
...

DSL KEYWORDS

validate

my $valid_hash_ref = validate_form $form

Returns $valid_hash_ref if validation succeed, otherwise returns undef.

validator_language

validator_language $lang

errors

my $errors_hash_multi = errors

Returns HashRef[ArrayRef] if validation failed.

Validators

accepted

alpha

Validate that string only contain of alphabetic utf8 symbols, i.e. /^[[:alpha:]]+$/.

alpha_ascii

Validate that string only contain of latin alphabetic ascii symbols, i.e. /^[[:alpha:]]+$/a.

alpha_num

Validate that string only contain of alphabetic utf8 symbols, underscore and numbers 0-9, i.e. /^\w+$/.

alpha_num_ascii

Validate that string only contain of latin alphabetic ascii symbols, underscore and numbers 0-9, i.e. /^\w+$/a.

email

email_dns

enum

integer

length_max

length_min

max

min

numeric

required

Validate that field exists and not empty string.

same

TODO

  • Configuration details: list all fields and describe them.

  • Document with example and descriptions DSL's.

  • Document with example all validators.

  • Document all config field with explanation.

  • Document all Roles and HashRef structures.

  • Extensions docs.

  • Contribution and help details.

BUGS AND LIMITATIONS

If you find one, please let me know.

SOURCE CODE REPOSITORY

https://github.com/AlexP007/dancer2-plugin-formvalidator.

AUTHOR

Alexander Panteleev <alexpan at cpan dot org>.

LICENSE AND COPYRIGHT

This software is copyright (c) 2022 by Alexander Panteleev. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.