undefined local variable or method `user' rails controller issue

Question

Beginner here...I'm trying to display an image but i'm getting the "undefined local variable or method `user'" error message. I think I know whats happening - there is no method but i just can't seem to get it working correctly with what i've tried. I've got a 'projects' model & controller...and a 'versions' model & controller. (pretty sure its just a controller issue so i've posted those files...just let me know if i need to post other files). I believe whats happening is when a user creates a new version the user_id is not being set (at least when I run "version.user_id" for a certain version id, it returns nil). How would i go about...

1) making sure the user_id is set in the db when the logged in user creates a version? 2) make sure there is a method in the versions index so i can display the profile pic for that user_id to created the version??

thanks in advance for any help...

THE ERROR:

NameError in Versions#index
Showing /Users/user/Documents/clones/collab/app/views/versions/_version.html.erb where line #3 raised:

undefined local variable or method `user' for #<#<Class:0x00000101b39f28>:0x0000010828c1d0>

THE VERSIONS CONTROLLER:

class VersionsController < ApplicationController
  before_action :find_project

  def new
    @version = Version.new
  end

  def show
    @project = Project.find(params[:project_id])
    @version = Version.find(params[:id])
  end

  def index
    # @user = User.where(:id => @version.user_id) first figure out how to set user_id on new versions (its nil now)
    @versions = Version.paginate(page: params[:page])
  end

  def create
    @project = Project.find(params[:project_id])
    @version = @project.verions.build(version_params)
    if @version.save
      flash[:success] = "You've successfully added a version of this project"
      redirect_to project_path(@project)
    else
      render 'new'
    end
  end

  def edit

  end

  def update

  end

  def destroy

  end

  private

    def find_project
      @project = Project.find(params[:project_id])
    end

    def version_params
      params.require(:version).permit(:title, :project_id, :user_id)
    end
end

VERSIONS NEW VIEW:

<% provide(:title, 'New Version') %>

<div class="row-fluid">
  <div class="col-md-5 no-pad">
    <h1>Add a new version to this project</h1>
    <%= bootstrap_form_for @version, :url => project_versions_path do |f| %>

      <%= render 'shared/error_messages', object: f.object %>

      <%= f.text_field :title %>

      <div class="well">
        <h4>Drag and Drop your file here:</h4>
        <%= image_tag("wavicon-large-grey.png", alt: "add file") %>
      </div>

      <%= f.button "Create Now! ", class: "btn btn-lg btn-primary" %>
    <% end %>
  </div>

</div>

VERSIONS INDEX VIEW:

<% provide(:title, @versions ) %>

<div class="row-fluid">
  <section class="no-pad col-md-9">

    <%= render :partial => '/projects/project_header' %>

    <h4>Version History</h4>

    <%= will_paginate %>

    <ul class="versions">
      <% @project.versions.first(5).each do |version| %> 

        <%= render version %>

      <% end %>
    </ul>

    <!-- CAN REFACTOR TO BELOW FOR CLEANER CODE
    <ul class="versions">
      <%= render @versions %>
    </ul>
    -->

    <%= will_paginate %>

  </section>
</div>

_VERSION.HTML.ERB PARTIAL (linked to in index file above)

<li>
  <%= link_to project_version_path(@project, version) do %>
    <h6><%= image_tag user.image_url(:collaborator_thumb).to_s, :class => "profile-pic-thumb" %><%= version.title %>...</h6>
    <span class="timestamp pull-right">
      Created <%= time_ago_in_words(version.created_at) %> ago
      <span class="glyphicon glyphicon-time"></span>
    </span>

  <% end %>
</li>

VERSION.RB MODEL (not sure if needed):

class Version < ActiveRecord::Base
  belongs_to :project
  belongs_to :user
  validates :title, presence: true, length: { maximum: 140 }

  default_scope -> { order('created_at DESC') }
end

Answer 1

To resolve following error

undefined local variable or method 'user' for #<#<Class:0x00000101b39f28>:0x0000010828c1d0>

In your _version.html.erb partial,

Replace

<h6><%= image_tag user.image_url(:collaborator_thumb).to_s, :class => "profile-pic-thumb" %><%= version.title %>...</h6>

With

<h6><%= image_tag version.user.image_url(:collaborator_thumb).to_s, :class => "profile-pic-thumb" %><%= version.title %>...</h6>

Note version.user.image_url instead of user.image_url. You are getting error because user variable is not defined. BUT version is defined so to access the associated user record you can simply use version.user.

UPDATE

The association with User model is missing in Version model. Set it as below:

class Version < ActiveRecord::Base
  belongs_to :user
  ## ...
end

class User < ActiveRecord::Base
  has_many :versions
  ## ...
end 

UPDATE 2

To store the user_id for a Version instance. Update the new action in your controller as below:

def new 
  @version = @project.versions.build(user_id: @project.user_id) 
end

In the versions new view, add a hidden field for user_id:

<%= f.hidden_field :user_id %>

Update the versions index view as below:

   <ul class="versions">
      <% @project.versions.first(5).each do |version| %>    
        <%= render partial: "version", object: version %>    
      <% end %>
    </ul>

Answer 2

you need to do in _VERSION.HTML.ERB:

<h6><%= image_tag @version.user.image_url(:collaborator_thumb).to_s, :class => "profile-pic-thumb" %><%= version.title %>...</h6>

as you haven't defined user anywhere, by doing this you will be able to access user associated with @version.

You also need to put has_many and belongs_to association in Version and User model.