Simple pagination for Redis lists and sorted sets.
Simple pagination for Redis lists and sorted sets.
Make sure your redis server is running! Redis configuration is outside the scope of this README, but
check out the Redis documentation for more information.
Add this line to your application’s Gemfile:
gem 'redis_pagination'
And then execute:
$ bundle
Or install it yourself as:
$ gem install redis_pagination
Configure redis_pagination:
RedisPagination.configure do |configuration|
configuration.redis = Redis.new
configuration.page_size = 25
end
Use redis_pagination:
require 'redis_pagination'
RedisPagination.configure do |configuration|
configuration.redis = Redis.new(:db => 15)
configuration.page_size = 25
end
# List
add_items_to_list('items', RedisPagination.page_size + 2)
=> 1
items_paginator = RedisPagination.paginate('items')
=> #<RedisPagination::Paginator::ListPaginator:0x007f8109b08ba0 @key="items">
items_paginator.total_items
=> 27
items_paginator.total_pages
=> 2
items_paginator.total_pages(5)
=> 6
items = items_paginator.page(1)
=> {:current_page=>1, :total_pages=>2, :total_items=>27, :items=>["item_1", "item_2", "item_3", "item_4", "item_5", "item_6", "item_7", "item_8", "item_9", "item_10", "item_11", "item_12", "item_13", "item_14", "item_15", "item_16", "item_17", "item_18", "item_19", "item_20", "item_21", "item_22", "item_23", "item_24", "item_25"]}
items = items_paginator.page(2)
=> {:current_page=>2, :total_pages=>2, :total_items=>27, :items=>["item_26", "item_27"]}
# Sorted Set
add_items_to_sorted_set('items', RedisPagination.page_size + 2)
=> 1
items_paginator = RedisPagination.paginate('items')
=> #<RedisPagination::Paginator::SortedSetPaginator:0x007f8109a25828 @key="items">
items_paginator.total_items
=> 27
items_paginator.total_pages
=> 2
items_paginator.total_pages(5)
=> 6
items = items_paginator.page(1)
=> {:current_page=>1, :total_pages=>2, :total_items=>27, :items=>[["item_27", 27.0], ["item_26", 26.0], ["item_25", 25.0], ["item_24", 24.0], ["item_23", 23.0], ["item_22", 22.0], ["item_21", 21.0], ["item_20", 20.0], ["item_19", 19.0], ["item_18", 18.0], ["item_17", 17.0], ["item_16", 16.0], ["item_15", 15.0], ["item_14", 14.0], ["item_13", 13.0], ["item_12", 12.0], ["item_11", 11.0], ["item_10", 10.0], ["item_9", 9.0], ["item_8", 8.0], ["item_7", 7.0], ["item_6", 6.0], ["item_5", 5.0], ["item_4", 4.0], ["item_3", 3.0]]}
items = items_paginator.page(2)
=> {:current_page=>2, :total_pages=>2, :total_items=>27, :items=>[["item_2", 2.0], ["item_1", 1.0]]}
items = items_paginator.page(1, :with_scores => false, :reverse => false)
=> {:current_page=>1, :total_pages=>2, :total_items=>27, :items=>["item_1", "item_2", "item_3", "item_4", "item_5", "item_6", "item_7", "item_8", "item_9", "item_10", "item_11", "item_12", "item_13", "item_14", "item_15", "item_16", "item_17", "item_18", "item_19", "item_20", "item_21", "item_22", "item_23", "item_24", "item_25"]}
# If the key is non-existent, the paginate call will return a RedisPagination::Paginator::NonePaginator
items_paginator = RedisPagination.paginate('unknown-key-in-redis')
=> #<RedisPagination::Paginator::NonePaginator:0x007f956b8052c0>
items_paginator.total_items
=> 0
items_paginator.total_pages
=> 0
items_paginator.total_pages(5)
=> 0
items = items_paginator.page(1)
=> {:current_page=>1, :total_pages=>0, :total_items=>0, :items=>[]}
items = items_paginator.page(2)
=> {:current_page=>2, :total_pages=>0, :total_items=>0, :items=>[]}
The RedisPagination::Paginator::SortedSetPaginator
and RedisPagination::Paginator::ListPaginator
classes have an all
method that can be called to retrieve all elements from these data types for
a given key.
Valid options in the page
call for paginating a Redis list are:
:page_size
controls the page size for the call. Default is RedisPagination.page_size
.Valid options in the page
call for paginating a Redis sorted set are:
:page_size
controls the page size for the call. Default is RedisPagination.page_size
.:with_scores
controls whether the score is returned along with the item. Default is true
.:reverse
controls whether to return items in highest-to-lowest (true
) or lowest-to-highest order (false
). Default is true
.There is a difference between how sorted set data with scores is returned between the 2.x and the 3.x branch of the Ruby Redis client library.
If you are using the 2.x branch, you will get items returned with alternating item and score as follows:
{:current_page=>1, :total_pages=>2, :total_items=>27, :items=>["item_27", "27", "item_26", "26", "item_25", "25", "item_24", "24", "item_23", "23", "item_22", "22", "item_21", "21", "item_20", "20", "item_19", "19", "item_18", "18", "item_17", "17", "item_16", "16", "item_15", "15", "item_14", "14", "item_13", "13", "item_12", "12", "item_11", "11", "item_10", "10", "item_9", "9", "item_8", "8", "item_7", "7", "item_6", "6", "item_5", "5", "item_4", "4", "item_3", "3"]}
If you are using the 3.x branch, you will get items returned as an array of arrays, where the internal arrays are the item and score as follows:
{:current_page=>1, :total_pages=>2, :total_items=>27, :items=>[["item_27", 27.0], ["item_26", 26.0], ["item_25", 25.0], ["item_24", 24.0], ["item_23", 23.0], ["item_22", 22.0], ["item_21", 21.0], ["item_20", 20.0], ["item_19", 19.0], ["item_18", 18.0], ["item_17", 17.0], ["item_16", 16.0], ["item_15", 15.0], ["item_14", 14.0], ["item_13", 13.0], ["item_12", 12.0], ["item_11", 11.0], ["item_10", 10.0], ["item_9", 9.0], ["item_8", 8.0], ["item_7", 7.0], ["item_6", 6.0], ["item_5", 5.0], ["item_4", 4.0], ["item_3", 3.0]]}
git checkout -b my-new-feature
)git commit -am 'Added some feature'
)git push origin my-new-feature
)