Rails Nil don't understand the error - ruby-on-rails

I have the following error
undefined method `[]' for nil:NilClass
app/controllers/events_controller.rb:60:in `create'
I am not sure what they mean by nil in this case. Here my controller and line 60 is where the arrow is
def create
#event = current_customer.events.build(params[:event])
#location = #event.locations.build(params[:location])
--->#location.longitude = params[:location][:longitude]
#location.latitude = params[:location][:latitude]
respond_to do |format|
if #location.save
if #event.save
format.html { redirect_to #event, notice: 'Event was successfully created.' }
format.json { render json: #event, status: :created, location: #event }
else
format.html { render action: "new" }
format.json { render json: #event.errors, status: :unprocessable_entity }
end
end
end
end
I have two models an event and a locations, I am create the two events at the same time and events has many locations. The longitude are attr_accesor longitude and latitude. hidden field type.

params[:location] is very likely to be nil. Additionally, you should consider using nested model form to have cleaner code. Refer to the RailsCast on Nested Model Forms and the docs for fields_for.
Theoretically, your model classes should look something like this:
class Customer < ActiveRecord::Base
...
has_many :events
accepts_nested_attributes_for :events
...
end
class Event < ActiveRecord::Base
...
has_one :location
accepts_nested_attributes_for :location
...
end
class Location < ActiveRecord::Base
...
belongs_to :event
...
end
your controller like this:
class EventsController < ApplicationController
def new
current_customer.events.build({}, {}) # instantiate 2 empty events
end
def create
current_customer.events.build(params[:event])
if current_customer.save # should save all events and their associated location
...
end
end
end
and your view like this:
<%= form_for #customer do |f| %>
...
<%= f.fields_for :events do |e| %>
...
<%= e.fields_for :location, (e.build_location || e.location) do |l| %>
<%= l.hidden_field :longitude %>
<%= l.hidden_field :latitude %>
<% end %>
...
<% end %>
...
<% end %>

Either params is nil, or, more likely, params[:location] is nil.
Imagine:
a = [[1,2], [3,4], [5,6], nil, [7,8]]
a[0][0]
=> 1
a[3][0]
undefined method `[]' for nil:NilClass
Because fourth element is nil, so we can't use the [] method on it..
The conclusion is that params[:location] is nil, such that when you're trying to access an element of what you think is an array, you get a method error, because NilClass doesn't have the [] method (whereas an Array does)

Write to your console:
logger.debug params[:location].class
logger.debug params[:location].inspect
I suspect the data coming is isn't what you expect it to be (i.e. [:longitude] is not part of the hash params[:location]).

Related

Rails - Send associated form only if condition is met

 I have two models: one for contacts ("Contatos") and one for users ("Usuarios"). Contatos has_one Usuario , as follows:
class Contato < ApplicationRecord
has_one :usuario, dependent: :destroy
accepts_nested_attributes_for :usuario,
allow_destroy: true
And
class Usuario < ApplicationRecord
has_secure_password
belongs_to :contato
validates_presence_of :login, :password
validates_uniqueness_of :login
end
 I want to use one form for creating and editing both models. The _form partial that I currently have is this:
<%= form_with(model: contato, local: true) do |contato_form| %>
<%= if contato.errors.any?
showferr contato
end %>
#Here are the inputs for contato, I cut them out so it wouldn't be too long to read.
 Bellow (same file as above) there is a check box for the Contato model that I left on, it sets a Boolean in the model(and DB) telling if the contact has a user on not, additionally I use some JavaScript (Coffee) to toggle the whole user (Usuario) form part based on the checkboxe's value .
<div class="form-group">
<%= contato_form.label :possui_usuario, :class => 'inline-checkbox' do %>
Possui usuário
<%= contato_form.check_box :possui_usuario, {id: "hasUser", checked: #contato.possui_usuario} %>
<% end %>
</div>
</div>
<div id="userPart" class="findMe" <% unless #contato.possui_usuario %> style="display:none;" <% end %> >
<h2> Usuário: </h2>
<div class="container">
<%= contato_form.fields_for :usuario, #contato.usuario do |usuario_form| %>
<%= render partial: 'usuarios/campos_usuario', locals: {form: usuario_form, object: #contato} %>
<% end %>
</div>
</div>
<br/>
<div class="container-fluid text-right">
<%= contato_form.submit 'Confirmar', :class => 'btn-lg btn-success' %>
</div>
<% end %>
 The partial form for the Usuario model is rendering ok, but what I want to do is to only create and/or validate the user part if the checkbox is selected (if I say that the contact does have a user).
 Here's what I attempted last (there were many attempts):
At Contato model:
attr_accessor(:has_user)
#has_user = 0
before_validation do |record|
#has_user = record.possui_usuario
end
def self.user?
#has_user == 1
end
validates_presence_of :nome
validates_length_of :nome, in: 1..45
validates_presence_of :email
validates_format_of :email, with: email_regex
validates_associated :usuario, if: user?
Controller for Contato:
class ContatosController < ApplicationController
before_action :set_contato, only: [:show, :edit, :update, :destroy]
# GET /contatos
# GET /contatos.json
def index
#contatos = Contato.all
#page_title = 'Contatos'
end
# GET /contatos/1
# GET /contatos/1.json
def show
#page_title = 'Ver contato: ' + #contato.nome
end
# GET /contatos/new
def new
#contato = Contato.new
#contato.build_usuario
#contato.ativo = true
#page_title = 'Novo contato'
end
# GET /contatos/1/edit
def edit
#page_title = 'Editar contato: ' + #contato.nome
unless #contato.possui_usuario
#contato.build_usuario
end
end
# POST /contatos
# POST /contatos.json
def create
#contato = Contato.new(contato_params)
respond_to do |format|
if #contato.save
flash[:notice] = 'Contato foi criado com sucesso.'
format.html {redirect_to #contato}
format.json {render :show, status: :created, location: #contato}
else
flash[:warn] = "Erro ao criar contato."
format.html {render :new}
format.json {render json: #contato.errors, status: :unprocessable_entity}
end
end
end
# PATCH/PUT /contatos/1
# PATCH/PUT /contatos/1.json
def update
respond_to do |format|
if #contato.update(contato_params)
format.html {redirect_to #contato, notice: 'Contato foi atualizado com sucesso.'}
format.json {render :show, status: :ok, location: #contato}
else
format.html {render :edit}
format.json {render json: #contato.errors, status: :unprocessable_entity}
end
end
end
# DELETE /contatos/1
# DELETE /contatos/1.json
def destroy
#contato.destroy
respond_to do |format|
format.html {redirect_to contatos_url, notice: 'Contato deletado com sucesso.'}
format.json {head :no_content}
end
end
private
# Use callbacks to share common setup or constraints between actions.
def set_contato
#contato = Contato.find(params[:id])
end
# Never trust parameters from the scary internet, only allow the white list through.
def contato_params
params.require(:contato).permit(:id, :empresa_id,
:ativo, :nome,
:cargo, :celular,
:email, :nascimento,
:observacoes, :mensagem_instantanea,
:tipo_msg_inst, :possui_usuario,
usuario_attributes: [:login, :password, :permissoes, :id, :contato_id, :_destroy])
end
end
Sorry for the long question and big code blocks.
I see two holes in the data presented currently ...
First, your controller action where create is called is where you should be testing to see if you are calling to the model / activerecord.
Something like ...
def create
if #contato && #contato.usuarios # might be able to just do last half
respond_to do |format|
if #contato = #contato.create!(contato_params) # note the bang or '!'
format.html { redirect_to #contato, notice: 'contato was successfully created.' }
else
format.html { render :new }
end
end
end
end
Without seeing your controller - I am going to guess you didn't nest your controller via Rails strong_param feature properly. Note here - these two won't run, I'm not quite sure what information is needed, but I wanted you to make sure if you are nesting your models and using a single controller - you are away you need to nest your models in strong_params (google search nested rails strong_params for thousands of help / hits).
params.require(:contato).permit(:login, :password, usuario: [id, ...] )
If that's not it - also tell us if all the functionality of create/read/update/destroy works normally & you are just looking to limit it to create in certain circumstances?
Update - based on the controller - just move your check for create from the model & move it to the controller at the start of the #create action ... maybe start with ...
def create
# Note - here you will have to inspect contato_params to find syntax
if contato_params[:usuario_attributes][:contato_id]
... rest of action wrapped in here ...
end
end
... once again ... you will need to work out exact syntax - but just like you did with the edit - this spot is where you control the creation - not in the model.
More specifically I see this #contato.possui_usuario in the form ... that's probably the variable you want to check against in your controller, but perhaps my suggestion is more important - I can't tell you that with certainty - I'm also not sure you need the has_user trick per say in model & might be tempted to do a controller version in the private method section ...
class ContatosController
private
def has_user?
... whatever ...
end
Clarification from comment:
If I move the control over the user form part to the controller (which
makes a lot of sense) how would I about canceling the
validates_associated part of the model in case the user decides that
this contact wont have any users?
You don't move the form control (defined as variable in the form), you move the model method that deals with the form control to the controller - then you can wrap it all in a transaction to rollback any other changes OR if you build your activerecord out with #build it will do it for you.

In Rails How to display errors in my comment form after I submit it?

I have a very straight-forward task to fulfil --- just to be able to write comments under posts and if the comments fail validation display error messages on the page.
My comment model uses a gem called Acts_as_commentable_with_threading, which creates a comment model after I installed.
On my post page, the logic goes like this:
Posts#show => display post and a form to enter comments => after the comment is entered, redisplay the Post#show page which has the new comment if it passes validation, otherwise display the error messages above the form.
However with my current code I can't display error messages if the comment validation fails. I think it is because when I redisplay the page it builds a new comment so the old one was erased. But I don't know how to make it work.
My codes are like this:
Comment.rb:
class Comment < ActiveRecord::Base
include Humanizer
require_human_on :create
acts_as_nested_set :scope => [:commentable_id, :commentable_type]
validates :body, :presence => true
validates :first_name, :presence => true
validates :last_name, :presence => true
# NOTE: install the acts_as_votable plugin if you
# want user to vote on the quality of comments.
#acts_as_votable
belongs_to :commentable, :polymorphic => true
# NOTE: Comments belong to a user
belongs_to :user
# Helper class method that allows you to build a comment
# by passing a commentable object, a user (could be nil), and comment text
# example in readme
def self.build_from(obj, user_id, comment, first_name, last_name)
new \
:commentable => obj,
:body => comment,
:user_id => user_id,
:first_name => first_name,
:last_name => last_name
end
end
PostController.rb:
class PostsController < ApplicationController
before_action :authenticate_user!, except: [:index, :show]
def show
#post = Post.friendly.find(params[:id])
#new_comment = Comment.build_from(#post, nil, "", "", "")
end
end
CommentsController:
class CommentsController < ApplicationController
def create
#comment = build_comment(comment_params)
respond_to do |format|
if #comment.save
make_child_comment
format.html
format.json { redirect_to(:back, :notice => 'Comment was successfully added.')}
else
format.html
format.json { redirect_to(:back, :flash => {:error => #comment.errors}) }
end
end
end
private
def comment_params
params.require(:comment).permit(:user, :first_name, :last_name, :body, :commentable_id, :commentable_type, :comment_id,
:humanizer_answer, :humanizer_question_id)
end
def commentable_type
comment_params[:commentable_type]
end
def commentable_id
comment_params[:commentable_id]
end
def comment_id
comment_params[:comment_id]
end
def body
comment_params[:body]
end
def make_child_comment
return "" if comment_id.blank?
parent_comment = Comment.find comment_id
#comment.move_to_child_of(parent_comment)
end
def build_comment(comment_params)
if current_user.nil?
user_id = nil
first_name = comment_params[:first_name]
last_name = comment_params[:last_name]
else
user_id = current_user.id
first_name = current_user.first_name
last_name = current_user.last_name
end
commentable = commentable_type.constantize.find(commentable_id)
Comment.build_from(commentable, user_id, comment_params[:body],
first_name, last_name)
end
end
comments/form: (this is on the Posts#show page)
<%= form_for #new_comment do |f| %>
<% if #new_comment.errors.any? %>
<div id="errors">
<h2><%= pluralize(#new_comment.errors.count, "error") %> encountered, please check your input.</h2>
<ul>
<% #new_comment.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<% end %>
I would instead use nested routes to create a more restful and less tangled setup:
concerns :commentable do
resources :comments, only: [:create]
end
resources :posts, concerns: :commentable
This will give you a route POST /posts/1/comments to create a comment.
In your controller the first thing you want to do is figure out what the parent of the comment is:
class CommentsController < ApplicationController
before_action :set_commentable
private
def set_commentable
if params[:post_id]
#commentable = Post.find(params[:post_id])
end
end
end
This means that we no longer need to pass the commentable as form parameters. Its also eliminates this unsafe construct:
commentable = commentable_type.constantize.find(commentable_id)
Where a malicous user could potentially pass any class name as commentable_type and you would let them find it in the DB... Never trust user input to the point where you use it to execute any kind of code!
With that we can start building our create action:
class CommentsController < ApplicationController
before_action :set_commentable
def create
#comment = #commentable.comments.new(comment_params) do |comment|
if current_user
comment.user = current_user
comment.first_name = current_user.first_name
comment.last_name = current_user.last_name
end
end
if #comment.save
respond_to do |format|
format.json { head :created, location: #comment }
format.html { redirect_to #commentable, success: 'Comment created' }
end
else
respond_to do |format|
format.html { render :new }
format.json { render json: #comment.errors, status: 422 }
end
end
end
private
# ...
def comment_params
params.require(:comment).permit(:first_name, :last_name, :body, :humanizer_answer, :humanizer_question_id)
end
end
In Rails when the user submits a form you do not redirect the user back to the form - instead you re-render the form and send it as a response.
While you could have your CommentsController render the show view of whatever the commentable is it will be quite brittle and may not even provide a good user experience since the user will see the top of the post they where commenting. Instead we would render app/views/comments/new.html.erb which should just contain the form.
Also pay attention to how we are responding. You should generally avoid using redirect_to :back since it relies on the client sending the HTTP_REFERRER header with the request. Many clients do not send this!
Instead use redirect_to #commentable or whatever resource you are creating.
In your original code you have totally mixed up JSON and HTML responses.
When responding with JSON you do not redirect or send flash messages.
If a JSON POST request is successful you would either:
Respond with HTTP 201 - CREATED and a location header which contains the url to the newly created resource. This is preferred when using SPA's like Ember or Angular.
Respond with HTTP 200 - OK and the resource as JSON in the response body. This is often done in legacy API's.
If it fails do to validations you should respond with 422 - Unprocessable Entity - usually the errors are rendered as JSON in the response body as well.
Added.
You can scrap your Comment.build_from method as well which does you no good at all and is very idiosyncratic Ruby.
class PostsController < ApplicationController
before_action :authenticate_user!, except: [:index, :show]
def show
#post = Post.friendly.find(params[:id])
#new_comment = #post.comments.new
end
end
Don't use line contiuation (\) syntax like that - use parens.
Don't:
new \
:commentable => obj,
:body => comment,
:user_id => user_id,
:first_name => first_name,
:last_name => last_name
Do:
new(
foo: a,
bar: b
)
Added 2
When using form_for with nested resources you pass it like this:
<%= form_for([commentable, comment]) do |f| %>
<% end %>
This will create the correct url for the action attribute and bind the form to the comment object. This uses locals to make it resuable so you would render the partial like so:
I'm assuming your form_for submits a POST request which triggers the HTML format in CommentsController#create:
def create
#comment = build_comment(comment_params)
respond_to do |format|
if #comment.save
make_child_comment
format.html
format.json { redirect_to(:back, :notice => 'Comment was successfully added.')}
else
format.html
format.json { redirect_to(:back, :flash => {:error => #comment.errors}) }
end
end
end
So, if #comment.save fails, and this is an HTML request, the #create method renders create.html. I think you want to render Posts#show instead.
Keep in mind that if validations fail on an object (Either by calling save/create, or validate/valid?), the #comment object will be populated with errors. In other words calling #comment.errors returns the relevant errors if validation fails. This is how your form is able to display the errors in #new_comment.errors.
For consistency, you'll need to rename #new_comment as #comment in the posts#show action, otherwise you'll get a NoMethodError on Nil::NilClass.
TL;DR: You're not rendering your form again with your failed #comment object if creation of that comment fails. Rename to #comment in posts, and render controller: :posts, action: :show if #comment.save fails from CommentsController#create
I have figured out the answer myself with the help of others here.
The reason is that I messed up with the JSON format and html format (typical noobie error)
To be able to display the errors using the code I need to change two places ( and change #comment to #new_comment as per #Anthony's advice).
1.
routes.rb:
resources :comments, defaults: { format: 'html' } # I set it as 'json' before
2.
CommentsController.rb:
def create
#new_comment = build_comment(comment_params)
respond_to do |format|
if #new_comment.save
make_child_comment
format.html { redirect_to(:back, :notice => 'Comment was successfully added.') }
else
commentable = commentable_type.constantize.find(commentable_id)
format.html { render template: 'posts/show', locals: {:#post => commentable} }
format.json { render json: #new_comment.errors }
end
end
end

Ruby on Rails nested attributes not saving into database?

I'm trying to create a list of items within a "Todo list", however, I'm not sure if I'm doing this correctly with nested attributes. I think using a nested attribute is the right attempt because there's going to be a large list of items, and it will be associated with the correct "Todo list" based on ids.
Example of what the tables might look like when records are populated
Todo table
id list
1 grocery shopping
2 health insurance
Item table
id todo_id name
1 1 buy milk
2 1 buy cereal
3 2 Blue Shield
4 2 Healthnet
5 1 buy cherries
Although, with my attempt below, my application is not saving any of the data into the Item database.
Todo Controller
class TodoController < ApplicationController
def new
#todo = Todo.new
#todo.items.build
end
end
Todo Model
class Todo < ActiveRecord::Base
belongs_to :user
has_many :items
accepts_nested_attributes_for :items
end
Item Model
class Item < ActiveRecord::Base
belongs_to :todo
end
Todo View
<%= simple_form_for(#todo) do |f| %>
<%= f.input :list %>
<%= f.simple_fields_for :items do |g| %>
<%= g.input :name %>
<% end%>
<%= f.button :submit %>
<% end %>
I was able to have the name field show up in my view, but when I save it, it doesn't save into the database, however, I'm able to save the list into the database, and then when I try to edit the record, the name field doesn't show up anymore to be able to edit.
EDIT: to show create method
This is my current Create Method in Todo Controller
def create
#todo = Todo.new(todo_params)
respond_to do |format|
if #todo.save
format.html { redirect_to #todo, notice: 'Todo was successfully created.' }
format.json { render :show, status: :created, location: #todo }
else
format.html { render :new }
format.json { render json: #todo.errors, status: :unprocessable_entity }
end
end
end
Not sure if Edit needs to have something, but I only have this from generating a scaffold of Todo
def edit
end
EDIT 2 show todo_params
def todo_params
params.require(:todo).permit(:user_id, :list)
end
You must add the nested params to your strong params
def todo_params
params.require(:todo).permit(:user_id, :list, items_attributes: [:id, :text, ...])
end
Note about todo_id :
You don't need to add :todo_id in items_attributes list, because you already have the TODO as context.
#todo = Todo.new(todo_params)
In the above code, your todo_params will contain some item_attributes linked to #todo. ie, it's similar to doing
#todo.items.build
It will already create an item with a todo_id corresponding to #todo.id
You need to add the items to the list of whitelisted attributes
def todo_params
params.require(:todo).permit(
:user_id,
:list,
items_attributes: [ # you're missing this
:id,
:name
]
)
end

Rails: trouble sorting array from view

So I'm trying to let the user sort an array of recipes from a link in my view:
<%= link_to "Score", recipes_sort_path, :order => 'score' %>
I send the parameter "score" to my controller method "sort", which looks like this:
def sort
if (params[:order] == 'score')
#recipes.sort_by(&:score)
end
respond_to do |format|
format.html { redirect_to recipes_path }
format.json { render json: #recipe }
end
end
It redirects to the following index method:
def index
# If recipes already present, skip following
if (!#recipes)
if (params[:search] || params[:tag])
#recipes = Recipe.search(params[:search], params[:tag])
else
#recipes = Recipe.all
end
end
respond_to do |format|
format.html
format.json { render json: #recipe }
end
end
The idea was to be redirected to the index view with the sorted list and just render the view.
I get no errors, but when I click the link, the page reloads but nothing happens.
The Recipe class looks like this:
class Recipe < ActiveRecord::Base
attr_accessible :instructions, :name, :slug, :score, :upvotes, :downvotes, :comments, :image
has_and_belongs_to_many :ingredients
has_and_belongs_to_many :tags
has_many :comments
belongs_to :user
delegate :name, :to => :user, :prefix => :user, :allow_nil => true
mount_uploader :image, ImageUploader
validates :name, :presence => true
def score
score = (self.upvotes - self.downvotes)
end
end
What am I doing wrong here?
There's a third option (the first 2 is from ckruse's answer). You can render the index template from the sort action
def sort
if (params[:order] == 'score')
#recipes.sort_by!(&:score)
end
respond_to do |format|
format.html { render :index }
format.json { render json: #recipe }
end
end
This will use the index template while using #recipes in the sort action. You also save one request because you're not redirecting.
One more thing I'd like to comment on is the link. It should be
<%= link_to "Score", recipes_sort_path(:order => 'score') %>
UPDATE: fetching #recipes. As much as possible, I want sql to do the sorting so that's what I'm going to do here.
def sort
#recipes = Recipe
if params[:order] == 'score'
#recipes = #recipes.order('upvotes - downvotes')
end
respond_to do |format|
format.html { render :index }
format.json { render json: #recipe }
end
end
First of all: sort_by is not „destructive,” it returns a new array. You may want to use sort_by! or save the return value of sort_by into #recipes.
Second: you do not render anything in your sort action at all. If you posted all code, even #recipes is empty. You can do two things:
Retreive the data in your sort method as you did in your index method and then call render :index
Sort in your index method and do not use a sort method at all. You can route multiple URIs to the same action.

Nil class error

I want to display the related products to a certain need, just the picture and the name nothing more depending on the categorie
here is mu controller
class RelatedneedsController < ApplicationController
def index
#relatedneeds = RelatedNeed.all
respond_to do |format|
format.html # index.html.erb
format.json { render json: #relatedneeds }
end
end
def show
s1 = '#need.category.name'
s2 = '#relatedneed.category.name'
if s1.eql?(s2)
#relatedneed = relatedneed.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render json: #need }
end
end
end
def get_name
#relatedneed.name
end
end
and this my model
class Relatedneed
include Mongoid::Document
include Mongoid::Paperclip
mapping do
indexes :name
end
field :name, type: String
belongs_to :category
belongs_to :user
end
and this is show.haml file
%h1
%b= #need.name
#container{:style => "width:1000px"}
#desc{:style => "height:400px;width:400px;float:left;"}
=image_tag #relatedneed.photo.url(:normal)
this is my index.haml file
%h1= #relatedneed.get_name
#container{:style => "width:1000px"}
#desc{:style => "background-color:#EEEEEE;height:400px;width:400px;float:left;"}
= link_to "Check Need", new_need_path
I don't know if their is something missing and i get this error
NoMethodError in RelatedneedsController#index
undefined method `key?' for nil:NilClass
Your index.haml has #relatedneed.get_name but you have not set #relatedneed in your controller, only #relatedneeds. Is it as simple as that?
Also, your show method in the controller makes no sense to me. You have put your instance variables inside strings! You need to set your instance variables with a database query via the model first. Your get_name method looks like it belongs in a model as well rather than a controller.

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