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Diffstat (limited to 'guides/source/active_record_validations.md')
| -rw-r--r-- | guides/source/active_record_validations.md | 59 |
1 files changed, 37 insertions, 22 deletions
diff --git a/guides/source/active_record_validations.md b/guides/source/active_record_validations.md index efa826e8df..c9af70934a 100644 --- a/guides/source/active_record_validations.md +++ b/guides/source/active_record_validations.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** + Active Record Validations ========================= @@ -85,7 +87,7 @@ end We can see how it works by looking at some `rails console` output: ```ruby -$ rails console +$ bin/rails console >> p = Person.new(name: "John Doe") => #<Person id: nil, name: "John Doe", created_at: nil, updated_at: nil> >> p.new_record? @@ -361,6 +363,8 @@ class Product < ActiveRecord::Base end ``` +Alternatively, you can require that the specified attribute does _not_ match the regular expression by using the `:without` option. + The default error message is _"is invalid"_. ### `inclusion` @@ -425,7 +429,7 @@ class Essay < ActiveRecord::Base validates :content, length: { minimum: 300, maximum: 400, - tokenizer: lambda { |str| str.scan(/\w+/) }, + tokenizer: lambda { |str| str.split(/\s+/) }, too_short: "must have at least %{count} words", too_long: "must have at most %{count} words" } @@ -485,6 +489,8 @@ constraints to acceptable values: * `:even` - Specifies the value must be an even number if set to true. The default error message for this option is _"must be even"_. +NOTE: By default, `numericality` doesn't allow `nil` values. You can use `allow_nil: true` option to permit it. + The default error message is _"is not a number"_. ### `presence` @@ -524,9 +530,16 @@ If you validate the presence of an object associated via a `has_one` or `marked_for_destruction?`. Since `false.blank?` is true, if you want to validate the presence of a boolean -field you should use `validates :field_name, inclusion: { in: [true, false] }`. +field you should use one of the following validations: + +```ruby +validates :boolean_field_name, presence: true +validates :boolean_field_name, inclusion: { in: [true, false] } +validates :boolean_field_name, exclusion: { in: [nil] } +``` -The default error message is _"can't be blank"_. +By using one of these validations, you will ensure the value will NOT be `nil` +which would result in a `NULL` value in most cases. ### `absence` @@ -575,7 +588,9 @@ This helper validates that the attribute's value is unique right before the object gets saved. It does not create a uniqueness constraint in the database, so it may happen that two different database connections create two records with the same value for a column that you intend to be unique. To avoid that, -you must create a unique index in your database. +you must create a unique index on both columns in your database. See +[the MySQL manual](http://dev.mysql.com/doc/refman/5.6/en/multiple-column-indexes.html) +for more details about multiple column indexes. ```ruby class Account < ActiveRecord::Base @@ -616,10 +631,6 @@ The default error message is _"has already been taken"_. This helper passes the record to a separate class for validation. ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if record.first_name == "Evil" @@ -627,6 +638,10 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator +end ``` NOTE: Errors added to `record.errors[:base]` relate to the state of the record @@ -644,10 +659,6 @@ Like all other validations, `validates_with` takes the `:if`, `:unless` and validator class as `options`: ```ruby -class Person < ActiveRecord::Base - validates_with GoodnessValidator, fields: [:first_name, :last_name] -end - class GoodnessValidator < ActiveModel::Validator def validate(record) if options[:fields].any?{|field| record.send(field) == "Evil" } @@ -655,6 +666,10 @@ class GoodnessValidator < ActiveModel::Validator end end end + +class Person < ActiveRecord::Base + validates_with GoodnessValidator, fields: [:first_name, :last_name] +end ``` Note that the validator will be initialized *only once* for the whole application @@ -696,7 +711,7 @@ we don't want names and surnames to begin with lower case. ```ruby class Person < ActiveRecord::Base validates_each :name, :surname do |record, attr, value| - record.errors.add(attr, 'must start with upper case') if value =~ /\A[a-z]/ + record.errors.add(attr, 'must start with upper case') if value =~ /\A[[:lower:]]/ end end ``` @@ -869,7 +884,7 @@ should happen, an `Array` can be used. Moreover, you can apply both `:if` and ```ruby class Computer < ActiveRecord::Base validates :mouse, presence: true, - if: ["market.retail?", :desktop?] + if: ["market.retail?", :desktop?], unless: Proc.new { |c| c.trackpad.present? } end ``` @@ -908,8 +923,8 @@ end The easiest way to add custom validators for validating individual attributes is with the convenient `ActiveModel::EachValidator`. In this case, the custom validator class must implement a `validate_each` method which takes three -arguments: record, attribute and value which correspond to the instance, the -attribute to be validated and the value of the attribute in the passed +arguments: record, attribute, and value. These correspond to the instance, the +attribute to be validated, and the value of the attribute in the passed instance. ```ruby @@ -1127,15 +1142,15 @@ generating a scaffold, Rails will put some ERB into the `_form.html.erb` that it generates that displays the full list of errors on that model. Assuming we have a model that's been saved in an instance variable named -`@post`, it looks like this: +`@article`, it looks like this: ```ruby -<% if @post.errors.any? %> +<% if @article.errors.any? %> <div id="error_explanation"> - <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2> + <h2><%= pluralize(@article.errors.count, "error") %> prohibited this article from being saved:</h2> <ul> - <% @post.errors.full_messages.each do |msg| %> + <% @article.errors.full_messages.each do |msg| %> <li><%= msg %></li> <% end %> </ul> @@ -1149,7 +1164,7 @@ the entry. ``` <div class="field_with_errors"> - <input id="post_title" name="post[title]" size="30" type="text" value=""> + <input id="article_title" name="article[title]" size="30" type="text" value=""> </div> ``` |