I'm developing a RESTful API using Sinatra and DataMapper. When my models fail validation, I want to return JSON to indicate what fields were in error. DataMapper adds an 'errors' attribute to my model of type DataMapper::Validations::ValidationErrors. I want to return a JSON representation of this attribute.
Here's a single file example (gotta love Ruby/Sinatra/DataMapper!):
require 'sinatra'
require 'data_mapper'
require 'json'
class Person
include DataMapper::Resource
property :id, Serial
property :first_name, String, :required => true
property :middle_name, String
property :last_name, String, :required => true
end
DataMapper.setup :default, 'sqlite::memory:'
DataMapper.auto_migrate!
get '/person' do
person = Person.new :first_name => 'Dave'
if person.save
person.to_json
else
# person.errors - what to do with this?
{ :errors => [:last_name => ['Last name must not be blank']] }.to_json
end
end
Sinatra::Application.run!
In my actual app, I'm handling a POST or PUT, but to make the problem easy to reproduce, I'm using GET so you can use curl http://example.com:4567/person or your browser.
So, what I have is person.errors and the JSON output I'm looking for is like what's produced by the hash:
{"errors":{"last_name":["Last name must not be blank"]}}
What do I have to do to get the DataMapper::Validations::ValidationErrors into the JSON format I want?
So, as I was typing this up, the answer came to me (of course!). I've burned several hours trying to figure this out, and I hope this will save others the pain and frustration I've experienced.
To get the JSON I'm looking for, I just had to create a hash like this:
{ :errors => person.errors.to_h }.to_json
So, now my Sinatra route looks like this:
get '/person' do
person = Person.new :first_name => 'Dave'
if person.save
person.to_json
else
{ :errors => person.errors.to_h }.to_json
end
end
Hope this helps others looking to solve this problem.
I know, I am answering this late, but, in case you are just looking for just validation error messages, you can use object.errors.full_messages.to_json. For example
person.errors.full_messages.to_json
will result in something like
"[\"Name must not be blank\",\"Code must not be blank\",
\"Code must be a number\",\"Jobtype must not be blank\"]"
This will rescue on client side from iterating over key value pair.
Related
I am just learning Ruby and datamapper, I have read the docs about associations from the official DataMapper site, but I still have two problems.
First whenever I add associated object, I can not see it when displaying all objects.
I have test class like:
class Test
include DataMapper::Resource
property :id, Serial
property :name, String
has 1, :phonen, :through => Resource
end
And then phonen class like:
class Phonen
include DataMapper::Resource
property :id, Serial
property :number, String
belongs_to :test
end
Then I am creating those 2 objects
#test = Test.create(
:name => "Name here"
)
#phone = Phonen.create(
:number => "Phone number"
)
#test.phonen = #phone
#test.save
And I want to display them like that (I want to return json)
get '/' do
Test.all.to_json
end
What am I doing wrong? maybe its something with the to_json...
I honestly don't know..
But I have one additional question to this topic, lets say I managed to connect those two classes, if I display JSON will I get Phonen { } or just inside class { }?
I know its probably very easy question, but I can't figure it out. That's why I decided to ask you guys. Thanks for help
Test.all
Is returning an active record association in array form, not a hash, when you try to convert to json it's failing.
You can try:
render json: Test.all
As asked in this question:
Ruby array to JSON and Rails JSON rendering
I am trying to take data from a path in Sinatra, and use it to look up a particular record using Datamapper. The Datamapper docs seem to indicate that.
get "/test/:test_path" do
test_get = Intake.get( params[:test_path] )
# Do stuff
erb :blah_blah_blah
end
should find any records associated with the symbol :test_path
This does not work. test_get gets nil.
Meanwhile, what does work is
get "/test/:test_path" do
test_all = Intake.all(:test_path => params[:test_path] )
# Do stuff
erb :blah_blah
end
My two questions are:
What am I doing wrong with the .get() call in Datamapper?
Is the .all(:name => value) method slower than .get(), or does it not matter which I use?
Here's a Sinatra script pared down to demonstrate the behavior.
#!/usr/bin/env ruby
require 'rubygems'
require 'sinatra'
require 'dm-core'
require 'dm-timestamps'
DataMapper.setup(:default, {:adapter => 'yaml', :path => 'db'})
class Intake
include DataMapper::Resource
property :id, Serial
property :created_at, DateTime
property :test_path, String
end
get "/test/:test_path" do
test_all = Intake.all(:test_path => params[:test_path] )
puts 'test_all:' test_all.inspect
test_get = Intake.get( params[:test_path] )
puts 'test_get:' test_get.inspect
"Hello World!"
end
#get only does a lookup based on primary key, with is the id. So
Intake.get(params[:test_path])
looks for something with id params[:test_path], which will fail. Use
Intake.first(test_path: params[:test_path])
I know the title is a bit vague, but I dont know what to put on there.
I'm developing an API with Sinatra for our backend in Ruby. The thing is that I need to be able to pass JSON to the service representing a User. The problem I'm facing is that when I run my tests it does not work, but doing it manually against the service it does work. I'm guessing there is an issue with the JSON format.
I've updated my User model to rely on the helpers from ActiveModel for the JSON serialization. I was running in too much problems with manual conversions. This is what the base User model looks like:
class User
include ActiveModel::Serializers::JSON
attr_accessor :login, :email, :birthday, :created_at, :updated_at, :password_sha, :password_salt
# Creates a new instance of the class using the information stored
# in the hash. If data is missing then nill will be assigned to the
# corresponding property.
def initialize(params = {})
return if params.nil?
self.login = params[:login] if params.key?("login")
self.email = params[:email] if params.key?("email")
self.birthday = Time.parse(params[:birthday]) rescue Time.now
if params.key?("password_salt") && params.key?("password_sha")
self.password_salt = params["password_salt"]
self.password_sha = params["password_sha"]
elsif params.key?("password")
self.set_password(params[:password])
end
self.created_at = Time.now
end
def attributes
{:login => self.login, :email => self.email, :birthday => self.birthday, :created_at => self.created_at, :updated_at => self.updated_at, :password_sha => self.password_sha, :password_salt => self.password_salt}
end
def attributes=(params = {})
self.login = params['login']
self.email = params['email']
self.birthday = params['birthday']
self.created_at = params['created_at']
self.updated_at = params['updated_at']
self.password_sha = params['password_sha']
self.password_salt = params['password_salt']
end
end
I'm using Cucumber, Rack::Test and Capybara to test my API implementation.
The code of the API application looks like this:
# This action will respond to POST request on the /users URI,
# and is responsible for creating a User in the various systems.
post '/users' do
begin
user = User.new.from_json(request.body.read)
201
rescue
400
end
end
In the above piece I expect the json representation in the request body. For some reason the params hash is empty here, don't know why
The test section that makes the actuall post looks like this:
When /^I send a POST request to "([^\"]*)" with the following:$/ do |path, body|
post path, User.new(body.hashes.first).to_json, "CONTENT_TYPE" => "application/json"
end
The example output JSON string generated by the User.rb file looks like this:
"{"user":{"birthday":"1985-02-14T00:00:00+01:00","created_at":"2012-03-23T12:54:11+01:00","email":"arne.de.herdt#gmail.com","login":"airslash","password_salt":"x9fOmBOt","password_sha":"2d3afc55aee8d97cc63b3d4c985040d35147a4a1d312e6450ebee05edcb8e037","updated_at":null}}"
The output is copied from the Rubymine IDE, but when I submit this to the application, I cannot parse it because:
The params hash is empty when using the tests
doing it manually gives me the error about needing at least 2 octets.
Update: I've switched to CarrierWave (finally got it to work), so although I still appreciate answers to this question I won't be able to try if they actually work since I've completely removed DM-Paperclip from my code.
Hi there,
I'm developing a Sinatra-webapp using DataMapper and are now looking to add some upload-functionality with S3 as storage. I've tried CarrierWave, but I couldn't get that to work so now I'm trying dm-paperclip. This is what I have right now:
Model:
class Article
include DataMapper::Resource
include Paperclip::Resource
property :id, Serial
property :created_at, DateTime
property :updated_at, DateTime
property :title, String
property :body, Text
has_attached_file :screenshot,
:storage => :s3,
:s3_credentials => {
:access_key_id => 'my-access-key-id',
:secret_access_key => 'my-secret_access-key',
:bucket => 'my-bucket'
},
:styles => {
:medium => "300x300>",
:thumb => "100x100>"
}
end
Controller:
post '/articles/create' do
#article = Article.new
#article.title = params[:title]
#article.body = params[:body]
#article.screenshot = params[:screenshot]
begin
#article.save
rescue DataMapper::SaveFailureError => e
puts "Error saving article: #{e.to_s} validation: #{#article.errors.values.join(', ')}"
rescue StandardError => e
puts "Got an error trying to save the article #{e.to_s}"
end
redirect '/articles'
end
Yet when I create a new article it doesn't save anything to my S3 bucket and I don't get any errors either.
Any ideas what I'm doing wrong?
Hey! Please try my fork: https://github.com/solnic/dm-paperclip it includes many patches which have fixed some issues with S3. Within a month or two I will be releasing it.
Apart from the solutions already posted, I would like to add a recomendation.
In my experience, using DataMapper's raise_on_save_failure feature is not of much help for debugging options. I recommend you disable that feature and use something like the following code:
if model.save then
return model
else
error = String.new
model.errors.each do |e|
error << "#{e[0]}\n"
end
raise ArgumentError, error
end
That way, you will get a full explanation of every issue DM encountered when trying to persist your model. I find it very useful not only for debugging but also for showing those messages to the consumers of my application.
Some time ago I did my fork especially for S3 in mind. My fork work with official AWS-SDK, instead of old aws-s3 which is mostly outdated.
If anybody will search for S3 solution for paperclip this is one that work (today)
https://github.com/krzak/dm-paperclip-s3
take a look at readme to get how to configure paperclip for S3
When using accepts_nested_attributes_for, I got stuck when having a validation which required the original to be present. The code will help clear up that sentence.
class Foo < ActiveRecord::Base
has_one :bar
accepts_nested_attributes :bar
end
class Bar < ActiveRecord::Base
#property name: string
belongs_to :foo
validates_presence_of :foo #trouble line!
end
#now when you do
foo = Foo.create! :bar_attributes => {:name => 'steve'}
#you get an error because the bar validation failed
I would like to write a validation that goes something like...
class Bar < ActiveRecord::Base
validates_presence_of :foo, :unless => :being_built_by_foo?
end
I am currently using rails3.beta4
Thank you
Alas I don't have an answer to this post, but the I came up with another way so I didn't need the validation.
Since bar should never be without a foo then any request to create a bar without a foo_id is an error. In the real example a foo is a project, and bar is a bid. It is a nested resource, but I wanted to give access to json apps to be able to query the info from the /bids location so the router looked like.
resources :bids
resources :projects do
resources: bids
end
and then I just had to make sure all html access used project_bids_path or form_for [:project,#bid] etc. This next part is largely untested but so far the desired behavior is there. I got the idea from Yehuda's post on generic actions http://yehudakatz.com/2009/12/20/generic-actions-in-rails-3/
#I'm sure there is a better way then map.connect
map.connect "projects/invalid_id", :controller => "projects", :action => "invalid_id"
resources :projects
resources :bids
end
#couple of changes from Yehuda
def redirect(*args, &block)
options = args.last.is_a?(Hash) ? args.pop : {}
path = args.shift || block
path_proc = path.is_a?(Proc) ? path : proc {|params| path % params }
status = options[:status] || 301
lambda do |env|
req = Rack::Request.new(env)
#Get both the query paramaters and url paramaters
params = env["action_dispatch.request.path_parameters"].merge req.params
url = path_proc.call(params.stringify_keys)
#Doesn't add the port back in!
#url = req.scheme + '://' + req.host + params
#content-type might be a bad idea, need to look into what happens for different requests
[status, {'Location' => url, 'Content-Type' => env['HTTP_ACCEPT'].split(',').first}, ['Moved Permanently']]
end
end
def bid_path
redirect do |params|
if params['project_id']
"/projects/#{params['project_id']}/bids/#{params['id']}"
else
'/projects/invalid_id'
end
end
end
match "bids", :to => bid_path
match "bids/:id", :to => bid_path
however, after doing all of this I most definitely don't think it worth it. I think nested_attributes breaks things and can be improved if that validation doesn't work, but after looking through the code for a little while I'm not sure exactly how to fix it or if it's worth it.
first of all, when using nested_attributes, you'll get the presence of the container. in the example: when you save Foo and there's also a nested form for Bar, then Bar is built by Foo.
I think there's no need to make this kind of validation if you're sure to use Bar only in contexts with Foo.
btw, try to write validation as follow (new preferred syntax for Rails3):
validates :foo, :presence => true
hope this helps,
a.