I'm very new to Rails 3 and I've followed some tutorials and now I'm trying to "play" with the code created. I have followed the tutorial from http://guides.rubyonrails.org/getting_started.html
I'm am trying to render the form for new posts on the homepage with this code:
<%= render :partial => "posts/form" %>
The posts/_form.html.erb looks like this:
<%= form_for(#post) do |f| %>
<% if #post.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#post.errors.count, "error") %> prohibited this post from being saved:</h2>
<ul>
<% #post.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :title %><br />
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :content %><br />
<%= f.text_area :content %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
and this is the error I get:
undefined method `model_name' for NilClass:Class
Extracted source (around line #1):
1: <%= form_for(#post) do |f| %>
2: <% if #post.errors.any? %>
3: <div id="error_explanation">
4: <h2><%= pluralize(#post.errors.count, "error") %> prohibited this post from being saved:</h2>
Trace of template inclusion: app/views/home/index.html.erb
Rails.root: d:/server/cazare
Application Trace | Framework Trace | Full Trace
app/views/posts/_form.html.erb:1:in `_app_views_posts__form_html_erb___794893824_70478136_519766'
app/views/home/index.html.erb:5:in `_app_views_home_index_html_erb__967672939_70487520_0'
I understand that this may seem a piece of cake for some of you but I'm trying to understand how everything works on Rails so I hope you can understand me.
Thanks in advance !
#post variable is not instantiated in the Controller :)
so "#post = Post.new" inside the controller action should do the trick
Rails is attempting to build a form for the object #post. In order to do that, it needs to know what sort of object #post is; that way, it can find any existing data in the object and fill it into the form for you. Rails has a method grafted on to objects called model_name to do the lookup, but it won't be grafted onto NilClass (the class of the nil object).
I suspect that you haven't defined #post anywhere - it's an instance variable of the Controller, so you'd expect the controller to either find #post from the database, or to call #post = Post.new - so it's nil.
In the posts/_form.html.erb,
change
<%= form_for(#post) do |f| %>
to
<%= form_for(Post.new) do |f| %>
Related
I'm using Devise within Rails 5 and have added Enum/roles (Consumer, Designer) to the User model. When creating a new registration, I want the user to select a role, for which I've added a radio_button for each value/role:
<div id="user_role"
<% User.roles.keys.each do |role| %>
<%= f.radio_button :role, role %>
<%= f.label role.to_sym %>
<% end %>
</div>
It's showing the labels of both roles, but only the radio_button for the last role. Here are the roles defined in the User model:
enum role: [:consumer, :designer]
Any ideas on what I'm doing wrong here?
try to this way
<div id="user_role">
<% User.roles.keys.each do |role| %>
<%= f.radio_button :role, role %>
<%= f.label role.to_sym %>
<% end %>
</div>
or
<div id="user_role">
<% User.roles.each do |role| %>
<%= f.radio_button :role, role %>
<%= f.label role[0] %>
<% end %>
</div>
it's working fine in my local.I hope it's will be help you.
I'm trying to setup a messaging system in my site using the Mailboxer gem in Rails 4.
When my app gets to this code:
def fetch_params(key, *subkeys)
params[key].instance_eval do
case subkeys.size
when 0 then self
when 1 then self[subkeys.first]
else subkeys.map{|k| self[k] }
end
end
it returns the error: undefined method '[]' for nil:NilClass
I've tried to figure this out, but I'm not very experienced. I've been following this tutorial: http://jamestansley.com/2014/02/22/customizing-the-mailboxer-ruby-gem-2/
I tried removing the line of code returning the error just to see what would happen, after which I received the error wrong number of arguments (1 for 2..6).
Can anyone attempt to explain this code to me? Been having a really rough time implementing this feature.
view/conversations/_form:
<%= simple_form_for :conversation, url: :conversations do |f| %>
<%= f.input :recipients %>
<%= f.input :subject %>
<%= f.input :body %>
<div class="form-actions">
<%= f.button :submit, class: 'btn-primary' %>
<%= submit_tag 'Cancel', type: :reset, class: 'btn btn-danger' %>
</div>
<% end %>
view/conversations/show:
<h1><%= #conversation.subject %> </h1>
<!--may have to work on this view. don't know if i did the haml conversion correctly-->
<h1> <%= conversation.subject %> </h1>
<ul>
<% content_tag_for(:li, conversation.receipts_for(current_user)) do |receipt| %>
<%= message = receipt.message %>
<h3><%= message.subject %> </h3>
<p><%= message.body %> </p>
</ul>
<% render 'messages/form', conversation: conversation %>
<% end %>
And here's my github repo: https://github.com/portOdin/GoFavorIt-Heroku/blob/8cd19ff5b61eb805dc694a6586f50df608752be2/app/views/conversations/show.erb
pls can someone explain how I can dynamically add another copy of a form in rails?...been working on this for almost 2hrs. I messed around with .clone() and .appendTo in jquery, but it didnt work. Also, most of the materials I found online (like on railscast #196 and stackoverflow) focused heavily on nested forms. My form is nested, but I actually just want to add the parent form again. The photos which are nested use the html multiple attributes so I'm guessing that will handle multiple files upload for each parent form (btw I'm using paperclip).
If I just need to modify the railscast code please let me know.
Thanks.
<%= form_for(#user_book, html: { multipart: true }) do |f| %>
<% if #user_book.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#user_book.errors.count, "error") %> prohibited this user_book from been saved:</h2>
<ul>
<% #user_book.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<p>hello</p>
<% end %>
</ul>
</div>
<% end %>
<%= f.text_field :title, placeholder: "enter title...", id: "book_title" %>
<%= f.text_field :category, placeholder: "enter category..." %>
<%= file_field_tag 'user_book[user_book_photos_attributes][][photo]', :multiple => true do |p| %>
<%= p.file_field :photo %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
I'm using Rails 3.2 and I'm making my first Ajax request.
This is my code:
def create
#post = Post.find(params[:post_id])
#comment = Comment.new(params[:comment])
respond_to do |format|
if #comment.save
format.html {
redirect_to #post
}
format.js
else
format.html {
render 'posts/show'
}
format.js
end
end
end
So, I understand that I return a js template.
So, question 1: Is really a good idea to use this approach instead the standard sending json / receiving json in a $.ajax call?
My create.js.erb:
$(".commentlist").append("<%= escape_javascript(render(:partial => #comment)) %>");
Working perfectly.
But... how I validate the form? (Without ajax works perfectly).
I'm seeing that the js.erb is like the html.erb but with js instead of html (I still see this weird, I think that is easier to use controller.coffee, but I will learn this way too :)).
So question 2: How I validate ? I see that what I get in the ajax call is the entire html and my two action vars (#post and #comment).
Just that, I need to learn the Rails approach to do ajax :)
P.S: My _form.html.erb:
<%= form_for comment, :url => post_comments_path(comment.post), :remote => true do |f| %>
<% if comment.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(comment.errors.count, "error") %> prohibited this comment from being added:</h2>
<ul>
<% comment.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<%= f.hidden_field :post_id %>
<p>
<%= f.label :name %>
<%= f.text_field :name %>
</p>
<p>
<%= f.label :email %>
<%= f.text_field :email %>
</p>
<p>
<%= f.label :url %>
<%= f.text_field :url %>
</p>
<p>
<%= f.label :content %>
<%= f.text_area :content %>
</p>
<p class="no-border">
<%= f.submit "Post", :class => "button" %>
</p>
<% end %>
Hi all I followed Ryan Bates' railscasts on nested models and form, but I am getting getting undefined method `klass' for nil:nilclass. I am pretty sure it is due to the the link_to_add_fields since everything was working prior. Below is my error and other relevant code and I'm using Rails 3.1. I did a lot of googling and did not find any to solve my problem, so if you guys could help me out I would really appreciated it. Thanks for your help.
_form.html.erb
<%= form_for(#organization) do |f| %>
<% if #organization.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#organization.errors.count, "error") %> prohibited this organization from being saved:</h2>
<ul>
<% #organization.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<div id="restaurant_field" class="field">
<%= f.fields_for :restaurants do |builder| %>
<%= render 'organizations/partials/restaurant_fields', :f => builder %>
<% end %>
</div>
<div class="actions"><%= f.submit %></div>
<% end %>
_restaurant_fields.html.erb
<p class="fields">
<%= f.label :name, "Restaurant Name" %><br />
<%= f.text_field :name %>
<%= link_to_remove_fields "Remove", f %>
application_helper.rb
module ApplicationHelper
def link_to_remove_fields(name, f)
f.hidden_field(:_destroy) + link_to_function(name, "remove_fields(this)")
end
def link_to_add_fields(name, f, association)
new_object = f.object.class.reflect_on_association(association).klass.new
fields = f.fields_for(association, new_object, :child_index => "new_#{association}") do |builder|
render(association.to_s.singularize + "_fields", :f => builder)
end
link_to_function(name, h("add_fields(this, \"#{association}\", \"#{escape_javascript(fields)}\")"))
end
end
application.js
function remove_fields(link) {
$(link).prev("input[type=hidden]").val("1");
$(link).closest(".fields").hide();
}
function add_fields(link, association, content) {
var new_id = new Date().getTime();
var regexp = new RegExp("new_" + association, "g");
$(link).parent().before(content.replace(regexp, new_id));
}
I found that the link_to_add_fields helper won't work if the associated model is describe by a has_one. The has_one means the association does not get the klass object.
You can determine this is your problem by changing your relationship to has_many :object + s (your object name with an s) and passing your object in plural to link_to_add_fields.
You have done the same thing as this person here
Edit: (error on my part)
I am assuming you have an link_to_add_fields below this line
<%= link_to_remove_fields "Remove", f %>
as it seems that the _restaurant_fields.html.erb partial is incomplete. (no closing tag)
</p>
Remove the link_to_add_fields outside of the f.fields_for
That should solve the klass error.