rails render missing variables

Question

for my rails app, my error messages are not displaying correctly. i think the reason was because on a failed validation, my controller did a redirect as opposed to a render. however, im having trouble rendering. all my variables seem to be missing. for example in my pub_messages#create i have...

def create
    @pub_message = current_user.pub_messages.build
    @pub_message.to_id = params[:pub_message][:to_id]
    @pub_message.user_id = current_user.id
    @pub_message.content = params[:pub_message][:content]
    if @pub_message.save
        flash[:success ] = "Your post has been sent"
        redirect_to user_path(params[:pub_message][:to_id])
    else
        render 'users/show'
    end
end

^(on a side note, im maually saving each of the attributes because of some security issue so i didn't make :to_id attr_accessible)

but back on point, when i do render 'users/show', it seems like it can't find any of my variables. it goes into my users show view, which complains about...

undefined method `name' for nil:NilClass
1: <% provide(:title, @user.name) %>

however, if it went to my users#show action, i declared @user.

 def show
    @user = User.find(params[:id])
    @current_user = current_user
    if user_signed_in?
        @message = current_user.messages.build
        @pub_message = current_user.pub_messages.build
    end
    @feed_items = @user.feed.paginate(page: params[:page], per_page: 20)
 end

am i missing or doing something wrong? thank you

UPDATE: so it seems like it doesn't go to the show action. how could i resolve the error messages not displaying? if i do a redirect, doesn't it cause the browser to immediately request a new page? and hence my error messages would never come up?

UPDATE2: so...im actually not coming from the 'new' page of the model, but instead im coming from the users show template. and in the template, i have the following

<%= form_for([current_user, @pub_message])  do |f| %>
  <%= render 'shared/error_messages', object: f.object %>
    <%= f.hidden_field :to_id, :value => @user.id %>
  <div class="micropost_message_field">
    <%= f.text_area :content, placeholder: "Comments?", :id => 'public_message_text' %>
  </div>
  <%= f.submit "Post", class: "btn btn-large btn-primary" %>
<% end %>

which is where the object is getting built, and which ultimately goes to my pub_messages#create. if i do re-initialize all the variables, do i need to move all the templates in a shared folder as well because its complaining about that.

or is there a better way to do this? maybe like rendering 'new', and then redirecting to the users#show?

Gabriel Yarra · Accepted Answer · 2012-06-05 03:04:51Z

3

Redirect will show flash messages but it won't show validation errors. Since you aren't setting a flash error message, I'm guessing you want to display the validation errors for the model. For that you'll need to stick with render, not redirect.

In order to render, you'll need to initialize all the variables required for the show view (although I'm unclear on why you don't render 'new', which is ostensibly where the user is navigating from). To do that cleanly, you can move all the content of the show method to another method, and call that method from show and a failed create.

def initialize_show_vars
   @user = User.find(params[:id])
    @current_user = current_user
    if user_signed_in?
        @message = current_user.messages.build
        @pub_message = current_user.pub_messages.build
    end
    @feed_items = @user.feed.paginate(page: params[:page], per_page: 20)
end

def show
  initialize_show_vars
end

def create
  <stuff ...>
  if @pub_message.save
    <stuff ...>
  else
    flash[:error] = "Didn't work"
    initialize_show_vars
    render 'users/show'
  end
end

answered Jun 5, 2012 at 3:04

Gabriel Yarra

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2 Comments

Sasha Over a year ago

so...im actually not coming from the 'new' page of the pub_messages, but instead im coming from the users show template. if i do re-initialize all the variables, do i need to move all the templates in a shared folder as well? or is there a better way to do this? maybe like rendering 'new', and then redirecting to the users#show?

Rob Sobers Over a year ago

@Gabriel I'm running into the same issue as @Sasha and I was thinking about doing what you suggest, but it seems a bit hairy. Is this a best practice? In my mind, it's better than using redirect_to because that would lose @pub_message.errors and I like the consistency of always looking to .errors for validation errors instead of flash or session, but it still seems awkward. If render actually called the action, we'd be good to go, but I see how that could be problematic in other cases.

Anil · Accepted Answer · 2012-06-04 20:18:20Z

2

When you do render, the control goes directly from this action to the view template, and does not touch your users_controller. That is why your variables are missing.

However, when you redirect, it goes to the users_controller as if a new request came in from the user.

Instead of render 'users/show', try redirect_to :controller => :users, :action => :show, :id => current_user.id

Redirect does show flash notices and errors. Redirect is used very commonly in such situations.

Does that help?

edited Jun 4, 2012 at 20:18

answered Jun 4, 2012 at 20:09

Anil

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7 Comments

Sasha Over a year ago

oh i editted by post. doesn't redirect not show failed validations?

Anil Over a year ago

Is your problem with the undefined method name' for nil:NilClass` or with the messages not showing?

Sasha Over a year ago

if i take out the render and put a redirect, then the messages don't show up

Anil Over a year ago

Flash has three flavors: flash, flash.now, and flash.keep. Try/ research those.

Sasha Over a year ago

hmmm would it be possible to chat with you?

|

DVG · Accepted Answer · 2012-06-04 20:06:10Z

0

You aren't calling the show action, you're just rendering the template, so @user does not get defined.

You might try another redirect instead of rendering the template.

answered Jun 4, 2012 at 20:06

DVG

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