Simple pagination solution for previous and next page navigation.
We saw some websites using will_paginate or kaminari for pagination, but they just need previous and next page navigation, will_paginate or kaminari is overqualified.
Pagination in databae sometimes is slow because
- it sends a sql with OFFSET to get collection
- it sends additional sql with COUNT to get total number of record.
simple_paginate eliminates the additional COUNT sql, make your pagination faster.
will_paginate and kaminari uses page and per_page to calculate offset and limit, then send 2 sqls
SELECT * FROM posts OFFSET 20 LIMIT 10;
SELECT COUNT(*) FROM posts;
after getting total count, they can calculate total pages, then render page numbers, prev, next, first and last page links.
simple_paginate also uses page and per_page to calculate offset and limit, but it only sends 1 sql
SELECT * FROM posts OFFSET 20 LIMIT 11;
it fetches one more record (11 = 10 + 1) to calculate if there is a next page records, so it doesn't need to send COUNT sql.
## perform a paginate query:
@users = User.paginate(:page => params[:page], :per_page => params[:per_page])
## render previous page link:
<%= link_to_previous_page @users, 'Previous' %>
## render next page link:
<%= link_to_next_page @users, 'Next' %>
## render previous page link and next page link
<%= simple_paginate @users %>
You can configure the following default values by overriding these values using SimplePaginate.configure method.
default_per_page # 25 by default
There's a handy generator that generates the default configuration file into config/initializers directory. Run the following generator command, then edit the generated file.
% rails g simple_paginate:config
SimplePaginate includes a handy template generator, To edit your paginator, run the generator first:
% rails g simple_paginate:views
To run the test suite locally:
% bundle install
% rake spec:active_record_42
% rake spec:active_record_50
% rake spec:active_record_51