simple_paginate

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Simple pagination solution for previous and next page navigation.

Why simple_paginate

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

  1. it sends a sql with OFFSET to get collection
  2. it sends additional sql with COUNT to get total number of record.

simple_paginate eliminates the additional COUNT sql, make your pagination faster.

How simple_paginate works

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.

Usage

Query Basics

## perform a paginate query:
@users = User.paginate(:page => params[:page], :per_page => params[:per_page])

### Helpers

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 %>


### General configuration options

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


### Customizing the pagination helper

SimplePaginate includes a handy template generator, To edit your paginator, run the generator first:

% rails g simple_paginate:views


### Contribute

To run the test suite locally:

% bundle install % rake spec:active_record_42

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