will_paginate undefined method 'per'

Question

I recently installed the will_paginate gem to my development blog and I am having trouble. I added it to my gemfile: ``` gem 'will_paginate' ``` then fed it into the posts controller: ``` def index @posts = Post.paginate(:per_page => 5, :page => params[:page], :order => 'created_at DESC') respond_to do |format| format.html # index.html.erb format.json { render json: @posts } format.atom end end ``` and finally into the view: ```

<%= post.content.html_safe %>

Posted: <%= post.created_at.to_formatted_s(:long) %>

Author: <%= post.author_name %>

Comments: <%= post.comments.count %>

<%= will_paginate @posts %> ``` The index page works OK. It is not paginated currently because I don't…

Accepted Answer

Looks like ActiveAdmin uses Kaminari for its pagination which conflicts with will_paginate.

See here for a work around: https://github.com/gregbell/active_admin/blob/47aa68d33da02c2c05cf1769402aac3df0ad02c7/docs/0-installation.md

```
# config/initializers/kaminari.rb
Kaminari.configure do |config|
  config.page_method_name = :per_page_kaminari
end
```

will_paginate undefined method 'per'

Solution

Problem