I am manually creating objects in the rails console using Model.new(<attributes here>). Is there an easy way to list out which attributes a model will require me to include in order for the .save call to succeed?
I am running rails 4.2.3
You can get an array of validators using Model.validators. You'll have to parse this in some way to extract those validations for presence, something like:
presence_validated_attributes = Model.validators.map do |validator|
validator.attributes if validator.is_a?(ActiveRecord::Validations::PresenceValidator)
end.compact.flatten
I found a simpler way to accomplish the same thing:
When you do a failed create you can check the error message on the object.
# app/models/price.rb
class Price < ActiveRecord::Base
validates_presence_of :value
end
# in console
p = Price.new()
=> #<Price id: nil, created_at: nil, updated_at: nil, value: nil>
p.save
=> false
p.errors.messages
=> {:value=>["can't be blank"]}
In case you the mandatory attributes with error messages
book = Book.new
book.valid?
book.errors.messages
In case you just want the name of attributes without an error message
book = Book.new
book.valid?
book.errors.messages.keys
Related
I've added ActionText into my Rails 5.2 app, according to this tutorial. I performed installation, migration and added action_text_rich_texts column. I also updated my model:
class LiveEvent < ApplicationRecord
has_rich_text :description_long
end
However has_rich_text helper seems to not working. When I try to initialize new record this way:
#live_event = LiveEvent.new(live_event_params)
description_long attribute returns nil because of this helper. Which crashes my app due to the validation constrains.
Strong param permission for description_long it's also not a case since that attribute was permitted before. This error occurs even if I want to add new record directly through the Rails console:
le = LiveEvent.new(description_long: 'test')
le[:description_long] // returns nil
Maybe there is no established binding between action_text_rich_texts and my LiveEvent model? I'm not sure what it the possible cause of this error. How can I fix it?
ActionText is providing polymorphic association with Model we mention has_rich_text.
So when we define has_rich_text is actually we are defining an association, like we do has_one, 'has_many', belongs_to.
So when you write
#live_event = LiveEvent.new(description_long: 'test')
It will create a new instance of ActionText::RichText model and assign the "text" in the body column as instance of ActionText::Content. So what ever value we assigned to description_long as rich text will automatically wrapped into into a div tag <div class="trix-content">.
Here is the example.
pry(main)> e = Email.new(content: "Asd")
=> #<Email:0x00007fd612746018
id: nil,
user_id: nil,
subject: nil,
created_at: nil,
updated_at: nil>
pry(main)> e.content
=> #<ActionText::RichText:0x00007fd612745c80
id: nil,
name: "content",
body: #<ActionText::Content "<div class=\"trix-conte...">,
record_type: "Email",
record_id: nil,
created_at: nil,
updated_at: nil>
pry(main)> e[:content]
=> nil
pry(main)> e.content.body.to_s
=> "<div class=\"trix-content\">\n Asd\n</div>\n"
so content in this example is not actually a column but it's a association. same way description_long in your example is an association not a column.
Please fine the note below "Note: you don't need to add a content field to your messages table." here in this guide https://edgeguides.rubyonrails.org/action_text_overview.html
In Ruby 1.9.2 on Rails 3.0.3, I'm attempting to test for object equality between two Friend (class inherits from ActiveRecord::Base) objects.
The objects are equal, but the test fails:
Failure/Error: Friend.new(name: 'Bob').should eql(Friend.new(name: 'Bob'))
expected #<Friend id: nil, event_id: nil, name: 'Bob', created_at: nil, updated_at: nil>
got #<Friend id: nil, event_id: nil, name: 'Bob', created_at: nil, updated_at: nil>
(compared using eql?)
Just for grins, I also test for object identity, which fails as I'd expect:
Failure/Error: Friend.new(name: 'Bob').should equal(Friend.new(name: 'Bob'))
expected #<Friend:2190028040> => #<Friend id: nil, event_id: nil, name: 'Bob', created_at: nil, updated_at: nil>
got #<Friend:2190195380> => #<Friend id: nil, event_id: nil, name: 'Bob', created_at: nil, updated_at: nil>
Compared using equal?, which compares object identity,
but expected and actual are not the same object. Use
'actual.should == expected' if you don't care about
object identity in this example.
Can someone explain to me why the first test for object equality fails, and how I can successfully assert those two objects are equal?
Rails deliberately delegates equality checks to the identity column. If you want to know if two AR objects contain the same stuff, compare the result of calling #attributes on both.
Take a look at the API docs on the == (alias eql?) operation for ActiveRecord::Base
Returns true if comparison_object is the same exact object, or comparison_object is of the same type and self has an ID and it is equal to comparison_object.id.
Note that new records are different from any other record by definition, unless the other record is the receiver itself. Besides, if you fetch existing records with select and leave the ID out, you’re on your own, this predicate will return false.
Note also that destroying a record preserves its ID in the model instance, so deleted models are still comparable.
If you want to compare two model instances based on their attributes, you will probably want to exclude certain irrelevant attributes from your comparison, such as: id, created_at, and updated_at. (I would consider those to be more metadata about the record than part of the record's data itself.)
This might not matter when you are comparing two new (unsaved) records (since id, created_at, and updated_at will all be nil until saved), but I sometimes find it necessary to compare a saved object with an unsaved one (in which case == would give you false since nil != 5). Or I want to compare two saved objects to find out if they contain the same data (so the ActiveRecord == operator doesn't work, because it returns false if they have different id's, even if they are otherwise identical).
My solution to this problem is to add something like this in the models that you want to be comparable using attributes:
def self.attributes_to_ignore_when_comparing
[:id, :created_at, :updated_at]
end
def identical?(other)
self. attributes.except(*self.class.attributes_to_ignore_when_comparing.map(&:to_s)) ==
other.attributes.except(*self.class.attributes_to_ignore_when_comparing.map(&:to_s))
end
Then in my specs I can write such readable and succinct things as this:
Address.last.should be_identical(Address.new({city: 'City', country: 'USA'}))
I'm planning on forking the active_record_attributes_equality gem and changing it to use this behavior so that this can be more easily reused.
Some questions I have, though, include:
Does such a gem already exist??
What should the method be called? I don't think overriding the existing == operator is a good idea, so for now I'm calling it identical?. But maybe something like practically_identical? or attributes_eql? would be more accurate, since it's not checking if they're strictly identical (some of the attributes are allowed to be different.)...
attributes_to_ignore_when_comparing is too verbose. Not that this will need to be explicitly added to each model if they want to use the gem's defaults. Maybe allow the default to be overridden with a class macro like ignore_for_attributes_eql :last_signed_in_at, :updated_at
Comments are welcome...
Update: Instead of forking the active_record_attributes_equality, I wrote a brand-new gem, active_record_ignored_attributes, available at http://github.com/TylerRick/active_record_ignored_attributes and http://rubygems.org/gems/active_record_ignored_attributes
META = [:id, :created_at, :updated_at, :interacted_at, :confirmed_at]
def eql_attributes?(original,new)
original = original.attributes.with_indifferent_access.except(*META)
new = new.attributes.symbolize_keys.with_indifferent_access.except(*META)
original == new
end
eql_attributes? attrs, attrs2
I created a matcher on RSpec just for this type of comparison, very simple, but effective.
Inside this file:
spec/support/matchers.rb
You can implement this matcher...
RSpec::Matchers.define :be_a_clone_of do |model1|
match do |model2|
ignored_columns = %w[id created_at updated_at]
model1.attributes.except(*ignored_columns) == model2.attributes.except(*ignored_columns)
end
end
After that, you can use it when writing a spec, by the following way...
item = create(:item) # FactoryBot gem
item2 = item.dup
expect(item).to be_a_clone_of(item2)
# True
Useful links:
https://relishapp.com/rspec/rspec-expectations/v/2-4/docs/custom-matchers/define-matcher
https://github.com/thoughtbot/factory_bot
If like me you're looking for a Minitest answer to this question then here's a custom method that asserts that the attributes of two objects are equal.
It assumes that you always want to exclude the id, created_at, and updated_at attributes, but you can override that behaviour if you wish.
I like to keep my test_helper.rb clean so created a test/shared/custom_assertions.rb file with the following content.
module CustomAssertions
def assert_attributes_equal(original, new, except: %i[id created_at updated_at])
extractor = proc { |record| record.attributes.with_indifferent_access.except(*except) }
assert_equal extractor.call(original), extractor.call(new)
end
end
Then alter your test_helper.rb to include it so you can access it within your tests.
require 'shared/custom_assertions'
class ActiveSupport::TestCase
include CustomAssertions
end
Basic usage:
test 'comments should be equal' do
assert_attributes_equal(Comment.first, Comment.second)
end
If you want to override the attributes it ignores then pass an array of strings or symbols with the except arg:
test 'comments should be equal' do
assert_attributes_equal(
Comment.first,
Comment.second,
except: %i[id created_at updated_at edited_at]
)
end
I have created a simple users model in rails 4.2. However I am unable to assign any attribute values in the rails console
2.1.5 :001 > u = User.new
=> #<User id: nil, name: nil, email: nil, auth_token: nil, created_at: nil, updated_at: nil, enabled: true>
2.1.5 :002 > u.name = 'sample'
=> "sample"
2.1.5 :003 > u.changed
=> []
2.1.5 :004 > u
=> #<User id: nil, name: nil, email: nil, auth_token: nil, created_at: nil, updated_at: nil, enabled: true>
As you can see despite setting name the value has not changed.
Here is the model file
class User < ActiveRecord::Base
self.primary_key = :id
include Tokenable
include Creatable
include Updatable
attr_accessor :name, :email, :auth_token, :created_at, :updated_at, :enabled
end
I know that this works fine in rails 3.2
One of the biggest "selling points" of ActiveRecord is that it automatically creates setters and getters in your models based on the DB schema.
These are not just your average accessors created by attr_accessor (which is plain Ruby), they cast values to the correct type and do dirty tracking among other things.
When you use attr_accessor you´re generating setters and getters that clobber those created by ActiveRecord - which means that AR will not track changes or persist the attributes.
This is what you really want:
class User < ActiveRecord::Base
include Tokenable
include Creatable
include Updatable
end
Only use attr_accessor in models when you need setters and getters for non-persisted ("virtual") attributes.
You need to save the record after assigning the new value. You can achieve that by calling update_attribute! or save! on your object. In your case:
u.name = "sample"
u.save!
or
u.update_attribute("name", "sample")
Note that update_attribute updates a single attribute and saves the record without going through the normal validation procedure
I'm new to Rails and am working on getting an application set up in Rails 4.2.4. I have a model called List that looks like the following in the database (PostgresQL):
List(id: integer, user_id: integer, name: string, created_at: datetime, updated_at: datetime, friendly_name: string)
and in List.rb:
class List < ActiveRecord::Base
attr_accessor :name, :friendly_name
belongs_to :user
has_many :items
end
I am trying to modify the name attribute from a controller action:
def save_name
...
list_to_edit = List.find(params[:id].to_i)
list_to_edit.name = params[:name]
list_to_edit.save!
...
end
But the changes are not being persisted. I have confirmed that params[:name] and list_to_edit are not nil. When I try to change the attribute in the Rails console like this:
> l = List.last
> l.name = 'TestName'
> l.save!
I don't see any errors. After executing the above commands and executing l.name I do see TestName. When I type l or List.last, however I still see
#<List id: 29, user_id: 17, name: nil, created_at: "2015-11-07 18:55:04", updated_at: "2015-11-07 18:55:04", friendly_name: nil>
What do I need to do to set the name attribute of a List? I can post any additional file content if it is helpful.
After trying a few more things it looks like all I needed to do was remove name from the array being passed to attr_accessor in List.rb. I believe when I was trying to change the list name with my_list.name = 'something' I was modifying the instance variable, not the attribute stored in the database.
I have a standard model with a few fields that are saved to a DB, and I need 1 field that doesn't have to be saved.
I tried attr_accessor but that doesn't cover it. Using Attr_accessor I can set and get the field, but it is not part of the model. If I add the models to an array and then see what is in the virtual field is not part of it. I also tried to add the field :headerfield to attr_accessible but that didn't change anything.
How can I get a field that is part of the model but not saved to the database?
The model
class Mapping < ActiveRecord::Base
attr_accessible :internalfield, :sourcefield
attr_accessor :headerfield
end
console output:
1.9.3-p194 :001 > m = Mapping.new
=> #<Mapping id: nil, internalfield: nil, sourcefield: nil, created_at: nil, updated_at: nil, data_set_id: nil>
1.9.3-p194 :002 > m.headerfield = "asef"
=> "asef"
1.9.3-p194 :003 > m
=> #<Mapping id: nil, internalfield: nil, sourcefield: nil, created_at: nil, updated_at: nil, data_set_id: nil>
Because ActiveRecord::Base has custom implementations for the standard serializiation methods (including to_s and as_json), you will never see your model attributes that do not have backing database columns unless you intervene in some way.
You can render it to JSON using the following:
render json: my_object, methods: [:virtual_attr1, :virtual_attr2]
Or you can use the as_json serializer directly:
my_object.as_json(methods: [:virtual_attr1, :virtual_attr2])
The return you see in the console is nothing else but the value of to_s. For this case, code should be better than natural language, take a look in the following code and see if you understand
class A
end
=> nil
A.new
=> #<A:0xb73d1528>
A.new.to_s
=> "#<A:0xb73d1528>"
class A
def to_s
"foobar"
end
end
=> nil
A.new
=> ble
A.new.to_s
=> "ble"
You can see this output because ActiveRecord::Base defines a method to_s that take into account only the attributes that are defined in the database, not the attr_accessor methods, maybe using the attributes call.