I'm using Mongoid on Rails, and added validates_uniqueness_of :quote on the model Quote.
But whenever there is a repeated record, the app crashes showing this message:
message: Validation of Quote failed. summary: The following errors
were found: Quote is already taken resolution: Try persisting the
document with valid data or remove the validations.
This is my model:
class Quote
include Mongoid::Document
field :quote, type: String
field :author, type: String
field :author_about, type: String
field :tags, type: String
validates_uniqueness_of :quote
end
And this is what I'm trying to do:
if #quotedb.save!
return true
else
return false
end
It should save if its unique, and ignore if its not, but never crash.
Your app didn't actually crash, it just throws an exception.
When you calls the save! method, the ! indicate it would trigger the validation, and when validation fails, it would raise an exception.
A better approach would be handle the exception using rescue, but if you don't care about the validation result, use save instead.
Related
I have a model that has
attr_accessible :name, :activity
validates :name, uniqueness: { scope: :activity }
It works and it doesn't allow the creation of duplicate entries. But with simple_form it only shows the error on the :name field. I'd like it to have errors on both fields saying that this 'name' and 'activity' combination has already been taken.
I'm thinking I need to create a custom validation method, but I'm hoping there's a more elegant solution that I've overlooked so far.
Is there a way to show errors on both these fields?
You can add another validation on :activity so that it will be marked as duplicate as well:
validates :activity, uniqueness: { scope: :name }
I'm not sure that's the most elegant solution but it will spare you the custom validation method.
I ended up doing
validates :name, uniqueness: { scope: :activity, message: 'This name and activity combination has already been taken.' }
I haven't decided if I'm going to have it validate both and put the message on both fields yet, but that opposite for the :activity field would be the same.
I would like to show some extra info in error messages resulting from a failed validation. For example suppose I have a class Book with the following validation
validates :name, presence: true, uniqueness: true
When someone tries to insert a book by the same name the following error message is returned
{"name":["has already been taken"]}
Instead I wanna show
{"name":["Book 'Great Expectaions' has already been taken at id:7"]}
Right now to make this happen I have to remove the uniqueness validation that I mentioned above and do the following
validate do |book|
existing_book = Book.find_by_name(book.name)
if existing_book
book.errors.add(:name, "#{existing_book.name} already exists at id: #{existing_book.id}")
end
end
Is there a way to get custom error messages like above without writing a custom uniqueness validation? I was thinking something along the lines of
validates :name, presence: true, uniqueness: {message: "#{self.name} already exists at id: #{Book.find_by_name(self.name).id}"
But this does not seem to work as self.name returns 'Book'. Is there a way to access the passed parameters in this context?
You'll have to do this as a custom validation. I would do it like so:
validate :name_is_unique
private
def name_is_unique
errors.add(:name, "#{other_book.name} already exists at id: #{other_book.id}") if other_book = Book.find_by_name(name)
end
The issue isn't really that you can't include the current model attributes in your validation, its that there's no 'one-liner' way to include another model. The good news is, that's what the validate method is for.
If it bothers you to have this in your model, just write a custom validator so it can be re-used application-wide.
I have a following code:
validates :name, :presence => true
Error message produced is "Name can't be blank"
Instead of using the actual attribute name (in this case "name") I want to
display message as "Registration name can't be blank".
How do I overwrite the default message on the validations? I tried appending :message
but it didn't work...
Thanks!
In en.yml file define custom keys as:
activerecord:
attributes:
model_name:
attribute_name1: key1
attribute_name2: key2
......
This key will be used automatically when errors are generated.
Reference: http://edgeguides.rubyonrails.org/i18n.html#translations-for-active-record-models
(5.1 Translations for Active Record Models)
This will do the trick:
validates :name, presence: { message: "Registration name can't be blank" }
or the old hash rocket syntax version:
validates :name, :presence => { :message => "Registration name can't be blank" }
Its a little late now (after about 35 days) to answer this. So, sorry for this. But just wanted to share that I had used a gem, more than a few months back, for custom error messages.
This plugin allows you to omit the attribute name for specific messages. All you have to do is begin the message with a ‘^’ character.
I just checked it at
https://github.com/nwise/custom_error_message
& it has not been updated since march. So, i probably used it at the right time.
ps : Your answer for defining the custom keys in the yml file is more appropriate though.
Is there a way to retrieve failed validations without checking the error message?
If I have a model with validates :name, :presence => true, :uniqueness => true, how can I check if determine what validation failed(was it uniqueness or was it presence?) without doing stuff like:
if error_message == "can't be blank"
# handle presence validation
elsif error_message = "has already been taken"
# handle uniqueness validation
end
There's a relatively new method that let you do just that, it's not documented anywhere as far as I know and I just stumbled on it while reading the source code, it's the #added? method:
person.errors.added? :name, :blank
Here's the original pull request: https://github.com/rails/rails/pull/3369
ActiveModel::Errors is nothing more than a dumb hash, mapping attributes names to human-readable error messages. The validations (eg. the presence one) directly add their messages to the errors object without specifying where they came from.
In short, there doesn't seem to be an official way of doing this.
You can Haz all your errors in the errors method. Try this on an saved unvalid record :
record.errors.map {|a| "#{a.first} => #{a.last}"}
Even though I'm pretty sure I know why this error gets raised, I don't seem to know why or how my session is exceeding the 4KB limit...
My app was working fine, but once I deliberately started adding bugs to see if my transactions were rolling back I started getting this error.
To give some background, I'm busy coding a tournament application that (in this section) will create the tournament and then add some tournament legs based on the number of teams as well as populate the the tournament with some 'ghost fixtures' once the legs have been created.
The flash[:tournament] was working correctly before; using a tournament object, I have access to any AR validation errors as well as data that has been entered on the previous page to create the tournament.
TournamentController.rb
begin
<other code>
Tournament.transaction do
tournament.save!
Tournament.generate_legs tournament
Tournament.generate_ghost_fixtures tournament
end
flash[:notice] = "Tournament created!"
redirect_to :action => :index
rescue Exception => e
flash[:tournament] = tournament
redirect_to :action => :new, :notice => "There was an error!"
end
Tournament.rb
self.generate_ghost_fixtures(tournament)
<other code>
#Generate the ghost fixtures
#tournament_legs is a has_many association
tournament_legs_array = tournament.tournament_legs
tournament_legs_array.each do |leg|
number_of_fixtures = matches[leg.leg_code]
#For the first round of a 32 team tournament, this block will run 16 times to create the matches
number_of_fixtures.times do |n|
Fixture.creatse!(:tournament_leg_id => leg.id, :match_code => "#{leg.leg_code}-#{n+1}")
end
end
end
I can do nothing but speculate as to why my session variable is exceeding 4KB??
Is it possible that the tournament object I pass through the flash variable contains all the associations as well?
Here is the dump of my session once I get the error.
Hope this is enough info to help me out :)
Thanks
Session Dump
_csrf_token: "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
flash: {:tournament=>#<Tournament id: nil, tournament_name: "asd", tournament_description: "asdasd", game_id: 1, number_of_teams: 16, start_date: "2011-04-30 00:00:00", tournament_style: "single elimination", tournament_status: "Drafting", active: true, created_at: "2011-04-30 10:07:28", updated_at: "2011-04-30 10:07:28">}
player_id: 1
session_id: "4e5119cbaee3d5d09111f49cf47aa8fa"
About dependencies, it is possible. Also save an ActiveRecord instance in the session is not a recommended aproach. You should save only the id. If you need it in all your requests use a before filter to retrieve it.
You can read more why is a bad idea at: http://asciicasts.com/episodes/13-dangers-of-model-in-session
The generally accepted and recommended approach is to not use a redirect on error, but a direct render instead. The standard "controller formula" is this:
def create
#tournament = Tournament.new(params[:tournament])
if #tournament.save
redirect ...
else
render 'new' # which will have access to the errors on the #tournament object and any other instance variable you may define
end
end
class Tournament < ActiveRecord::Base
before_create :set_up_legs
end
On successful saving, you can drop all instance variables (thereby wiping the in-memory state) and redirect to another page. On failure (or exception) you keep the object in memory and render a view template instead (typically the 'new' or 'edit' form page). If you're using standard Rails validation and error handling, then the object will have an errors array that you can just display.
I'd also recommend you use ActiveRecord associations which automatically give you transactions. If you push all this into the model, e.g. a "set_up_legs" method or something, then you can use ActiveRecord error handling. This is part of the "skinny controller, fat model" paradigm.
in session_store.rb, uncomment the last line with :active_record_store
Now restart the server
I would convert the exception to string before assigning it to flash[:tournament] with 'to_s'.
I had the same error and it seems assigning an exception object to a session variabla like flash means it takes the whole stack trace with it into the session. Try it, worked for me.