Rails 5 - undefined local variable or method `post' - ruby-on-rails

Question

I'm new to Rails. I've created a category model for my posts but when I go to display all posts associated with a particular category I get a NameError page
Here's my categories show.html.erb file:
<h1> <%= "Category: " + #category.name %></h1>
<div align="center">
<%= will_paginate #category_posts %>
</div>
<%= render 'posts/post', obj: #category_posts %>
<div align="center">
<% will_paginate #category_posts %>
</div>
I'm rendering the _post.html.erb partial to display posts that was defined in my post folder.
Looks like the issue is linked to the first line in the code below because the error message points to <li id="post-<%= post.id %>"> in the _post.html.erb code:
<li id="post-<%= post.id %>">
<span class="title"> <%=link_to post.title, post_path(post) %> </span>
<span class="content"><%= truncate(post.content, length: 100) if post.content? %></span>
<span class="content"> <%= image_tag post.picture.url if post.picture? %> </span>
<span class="content">
<% if post.category.any? %>
<p><%= render post.category %></p>
<% end %>
</span>
</li>
And this is my category controller file where I definite the "show" method:
class CategorysController < ApplicationController
before_action :require_admin, except: [:index, :show]
def index
#categories = Category.paginate(page: params[:page])
end
def new
#category = Category.new
end
def create
#category = Category.new(category_params)
if #category.save
flash[:success] = "Category created successfully"
redirect_to categories_path
else
render 'new'
end
end
def show
#category = Category.find(params[:id])
#category_posts = #category.posts.paginate(page: params[:page], per_page: 5)
end
The Post model:
class Post < ApplicationRecord
belongs_to :user
has_many :post_categories
has_many :categories, through: :post_category
default_scope -> { order(created_at: :desc) }
mount_uploader :picture, PictureUploader
validates :user_id, presence: true
validates :title, presence: true
validate :picture_size
private
# validates the size of an upload picture
def picture_size
if picture.size > 5.megabytes
errors.add(:picture, "should be less than 5MB")
end
end
end
The general idea is that when I go to localhost/categories/1 for example, I should have all the posts associated with that category.
Can anyone help me resolve this issue?

Answer 1

You probably mean to render a partial using a collection:
render(partial: 'posts/post', collection: #category_posts)
Where that should expand that partial to repeat once for each post and assign the local post variable.
obj isn't a valid argument, but object is if you want to render the content once with a given object.