Rails will_paginate 错误：未定义的方法 `total_pages'

Question

users_controller.rb:

@search_results = Notice.search('hello')
if(params[:query])
  @search_results = Notice.search(params[:query])
end

Notice.rb:

def self.search(search)
  if search
    Notice.where("content LIKE ?", "%#{search}%")
  else
  end
end

In the view:

<%= render 'shared/search_results' %>

_search_results.html.erb partial:

<% if @search_results.any? %>
  <ol class="notices">
    <%= render @search_results %>
  </ol>
  <%= will_paginate @search_results %>
<% end %>

I get the error: undefined method total_pages for #<Notice::ActiveRecord_Relation:0x0000010f3e8888> .

(It all works fine without pagination.)

How do I fix this error?

Answer 1

From the will paginate documentation:

## perform a paginated query:
@posts = Post.paginate(:page => params[:page])

# or, use an explicit "per page" limit:
Post.paginate(:page => params[:page], :per_page => 30)

## render page links in the view:
<%= will_paginate @posts %>

So, for your code you need to do:

search_results = Notice.search('hello').paginate(page: params[:page])
if(params[:query])
  @search_results = Notice.search(params[:query]).paginate(page: params[:page])
end

or the new Syntax in ActiveRecord 3

search_results = Notice.search('hello').page(params[:page])
if(params[:query])
  @search_results = Notice.search(params[:query]).page(params[:page])
end

Answer 2

I had this same challenge when working on a Rails 6 application.

This was my code:

def index
  if params[:query].present?
    @products = Product.search(params[:query])
  else
    @products = Product.paginate(page: params[:page], per_page: 30)
  end
  @brands = Brand.all
  @categories = Category.all
end

So whenever I try searching for products, it throws the error:

undefined method `total_pages' for #Product::ActiveRecord_Relation:0x00007f1f802423d0

Here's how I fixed it :

I simply added the paginate method to the if statement as well:

paginate(page: params[:page], per_page: 30)

So my code looked like this after that:

def index
  if params[:query].present?
    @products = Product.search(params[:query]).paginate(page: params[:page], per_page: 30)
  else
    @products = Product.paginate(page: params[:page], per_page: 30)
  end
  @brands = Brand.all
  @categories = Category.all
end

That's all.

I hope this helps