I load some models using custom SQL #find_by_sql because vanilla Rails relationships were too slow, and the models automatically have the extra attribute fields. Serializing works fine. However, when I deserialize, it complains that there is an unknown attribute. I tried without_protection but it didn't help. How do I deserialize my model and keep the extra attributes?
> Post.new(JSON.parse(json), without_protection: true)
ActiveRecord::UnknownAttributeError: unknown attribute: username
I tried to add attr_accessor fields, and that works for deserializing the models, but then it doesn't work for serializing!
> p.username
=> nil
> p.read_attribute :username
=> "test30"
> p.to_json
=> "{\"id\":129,\"user_id\":32,\"title\":\"The weird...\",\"username\":null}"
Ruby 2.0.0, Rails 4.0.3.
Ok I experimented with attr_writer, attr_reader, virtual fields from methods, and found a workaround but I still don't think this is the best way.
In the model:
attr_accessor :username
# override to_json
def to_json
hash = self.as_json
hash.merge!( {"username" => self.read_attribute(:username),
... other fields ...
} )
hash.to_json
end
However that causes nonsense like
> p = Post.loadFromDBviaFindBySQL.first
> p.username ### WTF?!
=> nil
> p.read_attribute :username
=> "starrychloe"
> json = p.to_json
=> "{\"id\":130,\"username\":\"starrychloe\" ... }"
> p1 = Post.new.from_json json
=> #<Post id: 130, ...>
> p1.username
=> "starrychloe"
> p1.read_attribute :username ### WTF?!
=> nil
I have to use nonsense like this in my views
post.username || post.read_attribute(:username) || post.user.username
Related
I have an ActiveRecord object and I would like to prevent it from being saved, without having permanent validations on the model. You used to be able to do something like this using errors.add but it doesn't look like it works anymore.
user = User.last
user.errors.add :name, "name doesn't rhyme with orange"
user.valid? # => true
user.save # => true
or
user = User.last
user.errors.add :base, "my unique error"
user.valid? # => true
user.save # => true
How can I prevent the user object from getting saved in Rails 3.2 without modifying it's model?
You can set errors, but do it within a validate method, e.g.:
validate :must_rhyme_with_orange
def must_rhyme_with_orange
unless rhymes_with_orange?
errors.add(:name, "doesn't rhyme with orange")
end
end
If you want to conditionally run the validation, one trick is to use attr_accessor and a guard condition:
attr_accessor :needs_rhyming
validate :must_rhyme_with_orange, :if => Proc.new {|o| o.needs_rhyming}
> u = User.last
> u.needs_rhyming = true
> u.valid? # false
Your issue is running valid? will rerun the validations.. resetting your errors.
pry(main)> u.errors[:base] << "This is some custom error message"
=> ["This is some custom error message"]
pry(main)> u.errors
=> {:base=>["This is some custom error message"]}
pry(main)> u.valid?
=> true
pry(main)> u.errors
=> {}
pry(main)>
Instead, just check if u.errors.blank?
This is a slight deviation from the original question, but I found this post after trying a few things. Rails has built in functionality to reject an object from saving if it has the _destroy attribute assigned as true. Quite helpful if you're handling model creation on the controller level.
I'm using attr_encrypted (v 1.2.0) in RoR 3.0.5 to encrypt credentials that I don't want appearing as plain text in my db. When I update the encrypted field, it appears that it's not getting saved into the db.
My model is essentially:
class Service << ActiveRecord::Base
attr_encrypted :credentials_aux, :key => KEY, :attribute => 'encrypted_credentials', :encode => true, :marshal => true
def credentials
credentials_aux
end
def credentials=(c)
h = {}.update(c) # coerce HashWithIndifferentAccess to a vanilla hash
credentials_aux = h
end
...
end
(Note that the 'credentials=' method exists simply to coerce a Rails-generated HashWithIndifferentAccess into a vanilla hash. It also gives me a place to interpose debugging printout to verify my data.)
But when I try updating credentials via the console, it doesn't take:
>> s = Service.find(19)
=> #<Service id: 19, encrypted_credentials: "10VfHU7IkdrFb4Q6Hj18YtY81rbRp3sIuoVUl8CHNj88cq1XFo2...",>
>> s.credentials
=> {"user_id"=>"fred.flintstone", "password"=>"supersecret"}
>> s.credentials = {"user_id" => "barney.rubble", "password" => "notsosecret"}
=> {"user_id" => "barney.rubble", "password" => "notsosecret"}
>> s.credentials
=> {"user_id"=>"fred.flintstone", "password"=>"supersecret"}
Why didn't s.credentials get updated to the new value?
I believe you're just setting a local variable called "credentials_aux" in your "credentials=" method, try explicitly using "self"
def credentials=(c)
h = {}.update(c) # coerce HashWithIndifferentAccess to a vanilla hash
self.credentials_aux = h
end
I'm actually the maintainer of that project, so if the fix above doesn't work then I'll open up a new ticket for this.
I want to use find_or_create_by, but this statement does NOT work. It does not "find" or "create" with the other attributes.
productproperty = ProductProperty.find_or_create_by_product_id(:product_id => product.id, :property_id => property.id, :value => d[descname])
There seems to be very little, or no, information on the use of dynamic finders in Rails 3. "and"-ing these together gives me a an unknown method error.
UPDATE:
Originally I couldn't get the following to work. Please assume I'm not an idiot and "product" is an instance of Product AR model.
product.product_properties.find_or_create_by_property_id_and_value(:property_id => 1, :value => "X")
The error methods was:
no such keys: property_id, value
I couldn't figure that out. Only this morning did I find the reference to passing the values like this instead:
product.product_properties.find_or_create_by_property_id_and_value(1, "X")
And voilá, it works fine. I would have expected a hash to work in the same situation but I guess not.
So I guess you get a down vote if you miss something on the internet?
If you want to search by multiple attributes, you can use "and" to append them. For example:
productproperty = ProductProperty.find_or_create_by_product_id_and_property_id_and_value(:product_id => product.id, :property_id => property.id, :value => d[descname])
There is one minor catch to be aware of. It will always return the object you've specified, even if that object can't be saved due to validation errors. So make sure you check to see if the returned object has an id (or is_valid?). Don't assume its in the database.
Alternatively, you can use the 'bang' version of the method to raise an error if the object cannot be saved:
http://guides.rubyonrails.org/active_record_querying.html#find-or-create-by-bang
This applies to Rails 3.
See http://api.rubyonrails.org/classes/ActiveRecord/Base.html:
With single query parameter:
productproperty = ProductProperty.find_or_create_by_product_id(product.id) { |u| u.property_id => property_id, u.value => d[descname] } )
or extended with multiple parameters:
productproperty = ProductProperty.find_or_create_by_product_id(:product_id => product.id, :property_id => property_id, :value => d[descname]) { |u| u.property_id => property_id, u.value => d[descname] } )
Would work with:
conditions = { :product_id => product.id,
:property_id => property.id,
:value => d[descname] }
pp = ProductProperty.find(:first, :conditions => conditions) || ProductProperty.create(conditions)
In Rails 4, you can use find_or_create_by(attr1: 1, attr2: 2) to find or create by multiple attributes.
You can also do something like:
User.create_with(
password: 'secret',
password_confirmation: 'secret',
confirmation_date: DateTime.now
).find_or_create_by(
email: 'admin#domain.com',
admin: true
)
If you need to create the user with some attributes, but cannot search by those attributes.
You could also use where(...).first_or_create - ActiveRecord::Relation#first_or_create.
product_property_attrs = { product_id: product.id,
property_id: property.id,
value: d[descname] }
product_property = ProductProperty.where(product_property_attrs).first_or_create
I've found in Rails 3.1 you do not need to pass the attributes in as a hash. You just pass the values themselves.
ProductProperty.find_or_create_by_product_id_and_property_id_and_value(
product.id, property.id, d[descname])
Here's some of my production code (I had to force line breaks):
task = Task.find_or_create_by_username_and_timestamp_and_des \
cription_and_driver_spec_and_driver_spec_origin(username,tim \
estamp,description,driver_spec,driver_spec_origin)
Yes, I'm trying to find or create a unique ActiveRecord::Base object. But in current form it's very ugly. Instead, I'd like to use something like this:
task = Task.SOME_METHOD :username => username, :timestamp => timestamp ...
I know about find_by_something key=>value, but it's not an option here. I need all values to be unique. Is there a method that'll do the same as find_or_create_by, but take a hash as an input? Or something else with similat semantics?
Rails 3.2 first introduced first_or_create to ActiveRecord. Not only does it have the requested functionality, but it also fits in the rest of the ActiveRecord relations:
Task.where(attributes).first_or_create
In Rails 3.0 and 3.1:
Task.where(attributes).first || Task.create(attributes)
In Rails 2.1 - 2.3:
Task.first(:conditions => attributes) || Task.create(attributes)
In the older versions, you could always write a method called find_or_create to encapsulate this if you'd like. Definitely done it myself in the past:
class Task
def self.find_or_create(attributes)
# add one of the implementations above
end
end
I also extend the #wuputah's method to take in an array of hashes, which is very useful when used inside db/seeds.rb
class ActiveRecord::Base
def self.find_or_create(attributes)
if attributes.is_a?(Array)
attributes.each do |attr|
self.find_or_create(attr)
end
else
self.first(:conditions => attributes) || self.create(attributes)
end
end
end
# Example
Country.find_or_create({:name => 'Aland Islands', :iso_code => 'AX'})
# take array of hashes
Country.find_or_create([
{:name => 'Aland Islands', :iso_code => 'AX'},
{:name => 'Albania', :iso_code => 'AL'},
{:name => 'Algeria', :iso_code => 'DZ'}
])
I have used globalize2 to add i18n to an old site. There is already a lot of content in spanish, however it isn't stored in globalize2 tables. Is there a way to convert this content to globalize2 with a migration in rails?
The problem is I can't access the stored content:
>> Panel.first
=> #<Panel id: 1, name: "RT", description: "asd", proje....
>> Panel.first.name
=> nil
>> I18n.locale = nil
=> nil
>> Panel.first.name
=> nil
Any ideas?
I'm sure you solved this one way or another but here goes. You should be able to use the read_attribute method to dig out what you're looking for.
I just used the following to migrate content from the main table into a globalize2 translations table.
Add the appropriate translates line to your model.
Place the following in config/initializers/globalize2_data_migration.rb:
require 'globalize'
module Globalize
module ActiveRecord
module Migration
def move_data_to_translation_table
klass = self.class_name.constantize
return unless klass.count > 0
translated_attribute_columns = klass.first.translated_attributes.keys
klass.all.each do |p|
attribs = {}
translated_attribute_columns.each { |c| attribs[c] = p.read_attribute(c) }
p.update_attributes(attribs)
end
end
def move_data_to_model_table
# Find all of the translated attributes for all records in the model.
klass = self.class_name.constantize
return unless klass.count > 0
all_translated_attributes = klass.all.collect{|m| m.attributes}
all_translated_attributes.each do |translated_record|
# Create a hash containing the translated column names and their values.
translated_attribute_names.inject(fields_to_update={}) do |f, name|
f.update({name.to_sym => translated_record[name.to_s]})
end
# Now, update the actual model's record with the hash.
klass.update_all(fields_to_update, {:id => translated_record['id']})
end
end
end
end
end
Created a migration with the following:
class TranslateAndMigratePages < ActiveRecord::Migration
def self.up
Page.create_translation_table!({
:title => :string,
:custom_title => :string,
:meta_keywords => :string,
:meta_description => :text,
:browser_title => :string
})
say_with_time('Migrating Page data to translation tables') do
Page.move_data_to_translation_table
end
end
def self.down
say_with_time('Moving Page translated values into main table') do
Page.move_data_to_model_table
end
Page.drop_translation_table!
end
end
Borrows heavily from Globalize 3 and refinerycms.