NAME

LIVR - Lightweight validator supporting Language Independent Validation Rules Specification (LIVR)

SYNOPSIS

Common usage:

    require 'LIVR'
    LIVR.default_auto_trim('is_auto_trim')

    validator = LIVR.new({
      'name'      => 'required',
      'email'     => [ 'required', 'email' ],
      'gender'    => { 'one_of' => ['male', 'female'] },
      'phone'     => { 'max_length' => 10 },
      'password'  => [ 'required', {'min_length' => 10} ],
      'password2' => { 'equal_to_field' => 'password' }
    })

    valid_data = validator.validate(user_data)

    if valid_data
      save_user(valid_data)
    else
      errors = validator.get_errors
    end

You can use modifiers separately or can combine them with validation:

    validator = LIVR.new({
      'email' => [ 'required', 'trim', 'email', 'to_lc' ]
    })

Feel free to register your own rules:

You can use aliases(prefferable, syntax covered by the specification) for a lot of cases:

    validator = LIVR.new({
      'password' => ['required', 'strong_password']
    })

    validator.register_aliased_rule({
      'name'  => 'strong_password',
      'rules' => {'min_length' => 6},
      'error' => 'WEAK_PASSWORD'
    })

Or you can write more sophisticated rules directly:

    validator = LIVR.new({
      'password' => ['required', 'strong_password']
    })

    validator.register_rules({
      'strong_password' => lambda do |args|
        lambda do |value, params, output|
          return if value.nil? or value.eql?('')
          return 'WEAK_PASSWORD' if value.to_s.length < 6
        end
      end
    })

DESCRIPTION

See 'LIVR Specification' for detailed documentation and list of supported rules.

Features:

• Rules are declarative and language independent
• Any number of rules for each field
• Return together errors for all fields
• Excludes all fields that do not have validation rules described
• Has possibility to validatate complex hierarchical structures
• Easy to describe and undersand rules
• Returns understandable error codes(not error messages)
• Easy to add own rules
• Rules are be able to change results output (trim, nested_object, for example)
• Multipurpose (user input validation, configs validation, contracts programming etc)

INSTALL

Install LIVR from RubyGems using gem::

    gem install livr

CLASS METHODS

LIVR.new(livr, is_auto_trim)

Contructor creates validator objects. livr - validations rules. Rules description is available here - LIVR

is_auto_trim - asks validator to trim all values before validation. Output will be also trimmed. if is_auto_trim is nil than default_auto_trim value will be used.

LIVR.register_aliased_default_rule(alias)

alias - is a hash that contains: name, rules, error (optional).

    LIVR.register_aliased_default_rule({
      'name'  => 'valid_address',
      'rules' => { 'nested_object' => {
        'country' => 'required',
        'city' => 'required',
        'zip' => 'positive_integer'
      }}
    })

Then you can use valid_address for validation:

    {
      'address' => 'valid_address'
    }

You can register aliases with own errors:

    LIVR.register_aliased_default_rule({
      'name' => 'adult_age',
      'rules' => [ 'positive_integer', { 'min_number' => 18 } ],
      'error' => 'WRONG_AGE'
    })

All rules/aliases for the validator are equal. The validator does not distinguish required, list_of_different_objects and trim rules. So, you can extend validator with any rules/alias you like.

LIVR.register_default_rules({"rule_name" => rule_builder })

rule_builder - is a lambda function which will be called for building single rule validator.

    LIVR.register_default_rules({
      'my_rule' => lambda do |args|
        rule_builders = args.pop
        # rule_builders - are rules from original validator
        # to allow you create new validator with all supported rules
        # validator = LIVR.new(livr).register_rules(rule_builders).prepare

        lambda do |value, params, output|
          return "SOME_ERROR_CODE" if notValid
        end
      end
    })

Then you can use my_rule for validation:

    {
      'name1' => 'my_rule', # Call without parameters
      'name2' => { 'my_rule': arg1 }, # Call with one parameter.
      'name3' => { 'my_rule': [arg1] }, # Call with one parameter.
      'name4' => { 'my_rule': [ arg1, arg2, arg3 ] } # Call with many parameters.
    }

Here is max_number implemenation:

    max_number = lambda do |args|
      max_number = args.shift
      lambda do |value, params, output|
        # We do not validate empty fields. We have "required" rule for this purpose
        return if value.nil? or value.eql?('')
        # return error message
        return 'TOO_HIGH' if value.to_f > max_number
      end
    end
    LIVR.register_default_rules({'max_number' => max_number})

All rules for the validator are equal. The validator does not distinguish required, list_of_different_objects and trim rules. So, you can extend validator with any rules you like.

LIVR.get_default_rules

returns object containing all default rule_builders for the validator. You can register new rule or update existing one with register_rules method.

LIVR.default_auto_trim(is_auto_trim)

Enables or disables automatic trim for input data. If is on then every new validator instance will have auto trim option enabled

OBJECT METHODS

validator.validate(input)

Validates user input. On success returns valid_data (contains only data that has described validation rules). On error return false.

    my valid_data = validator.validate(input)

    if valid_data
      # use valid_data
    else
      errors = validator.get_errors
    end

validator.get_errors

Returns errors object.

   {
      "field1" => "ERROR_CODE",
      "field2" => "ERROR_CODE",
        ...
    }

For example:

    {
      "country"  => "NOT_ALLOWED_VALUE",
      "zip"      => "NOT_POSITIVE_INTEGER",
      "street"   => "REQUIRED",
      "building" => "NOT_POSITIVE_INTEGER"
    }

validator.register_rules({"rule_name": rule_builder})

rule_builder - is a lambda function which will be called for building single rule validator.

See LIVR.register_default_rules for rules examples.

validator.register_aliased_rule(alias)

alias - is a composite validation rule.

See LIVR.register_aliased_default_rule for rules examples.

validator.get_rules

returns object containing all rule_builders for the validator. You can register new rule or update existing one with register_rules method.

AUTHOR

koorchik (Viktor Turskyi), maktwin (Maksym Panchokha)

BUGS

Please report any bugs or feature requests to Github ruby-validator-livr

LICENSE AND COPYRIGHT

Copyright 2012 Viktor Turskyi.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

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