Class: DenylistValidator

Inherits:
ActiveModel::EachValidator
  • Object
show all
Defined in:
lib/calagator/denylist_validator.rb

Overview

DenylistValidator

A naively simple mixin used to ban words in ActiveModel objects.

Usage

Let's say that your applications lets people post messages, but don't want them using the word “viagra” in posts as a naively simple way of preventing spam.

You'd first create a config/denylist.txt file with a line like:

\bviagrab\b

And then you'd include the denylisting feature into your Message class like:

class Message < ApplicationRecord
  validates :title, :content, denylist: true
end

Now including the word “viagra” in your record's values will fail:

message = Message.new(title: "foo viagra bar")
message.valid? # => false

Available validator options:

* patterns: Array of regular expressions that will be matched
  against the given attribute contents and any matches will cause the
  record to be marked invalid.
* denylist: Reads an array of denylisted regular expressions from
  a filename.
* message: Error message to use on invalid records.

If no :patterns or :denylist is given, patterns are read from:

* config/denylist.txt
* config/denylist-local.txt

Constant Summary collapse

DENYLIST_DEFAULT_MESSAGE = 
'contains denylisted content'

Instance Method Summary collapse

Instance Method Details

#validate_each(record, attribute, value) ⇒ Object 



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# File 'lib/calagator/denylist_validator.rb', line 42

def validate_each(record, attribute, value)
  if value.present? && patterns.any? { |pattern| value.match(pattern) }
    record.errors.add attribute, message
  end
end