How to Pass a Filter Param to a Read More Link_to Pagination, Rails

Kaminari

A Scope & Engine based, clean, powerful, customizable and sophisticated paginator for modern web app frameworks and ORMs

Features

Clean

Does not globally pollute Assortment, Hash, Object or AR::Base.

Like shooting fish in a barrel to Use

But parcel the gem, then your models are set up to exist paginated. No configuration required. Don't have to define anything in your models or helpers.

Simple Telescopic-based API

Everything is method chainable with less "Hasheritis". You know, that'due south the modern Rails way. No special collection class or anything for the paginated values, instead using a full general AR::Relation instance. So, of course you can chain whatever other atmospheric condition before or after the paginator scope.

Customizable Engine-based I18n-aware Helpers

Equally the whole pagination helper is basically just a collection of links and non-links, Kaminari renders each of them through its own fractional template within the Engine. Then, you can easily change their behaviour, style or whatsoever by overriding partial templates.

ORM & Template Engine Agnostic

Kaminari supports multiple ORMs (ActiveRecord, DataMapper, Mongoid, MongoMapper) multiple web frameworks (Rails, Sinatra, Grape), and multiple template engines (ERB, Haml, Slim).

Modern

The pagination helper outputs the HTML5 <nav> tag past default. Plus, the helper supports Rails unobtrusive Ajax.

Supported Versions

Ruby 2.1, ii.2, 2.3, 2.iv, ii.five, two.6, 2.vii, 3.0, 3.ane, three.2
Rails 4.ane, four.2, 5.0, 5.1, five.2, 6.0, vi.1, 7.0, 7.i
Sinatra ane.4, two.0
Haml 3+
Mongoid 3+
MongoMapper 0.9+
DataMapper 1.one.0+

Installation

To install kaminari on the default Track stack, just put this line in your Gemfile:

Then bundle:

If yous're building not-Track of not-ActiveRecord app and want the pagination feature on information technology, please take a expect at Other Framework/Library Support department.

Query Nuts

The `page` Telescopic

To fetch the 7th page of users (default per_page is 25)

Note: pagination starts at page 1, not at page 0 (page(0) volition return the same results every bit page(1)).

Kaminari does not add an order to queries. To avoid surprises, you should mostly include an order in paginated queries. For case:

              User              .              order              (              :name              )              .              folio              (              7              )

You tin become page numbers or page weather by using below methods.

              User              .              count              #=> thousand              User              .              page              (              1              )              .              limit_value              #=> twenty              User              .              folio              (              one              )              .              total_pages              #=> l              User              .              folio              (              1              )              .              current_page              #=> 1              User              .              page              (              1              )              .              next_page              #=> ii              User              .              page              (              2              )              .              prev_page              #=> ane              User              .              page              (              i              )              .              first_page?              #=> true              User              .              page              (              50              )              .              last_page?              #=> truthful              User              .              page              (              100              )              .              out_of_range?              #=> true

The `per` Telescopic

To show a lot more than users per each page (change the per value)

              User              .              guild              (              :proper noun              )              .              page              (              7              )              .              per              (              fifty              )

Notation that the per scope is non directly defined on the models just is just a method divers on the page scope. This is absolutely reasonable considering you will never actually use per without specifying the page number.

Continue in mind that per internally utilizes limit and and so it volition override any limit that was ready previously. And if you want to become the size for all request records you can use total_count method:

              User              .              count              #=> 1000              a              =              User              .              limit              (              5              )              ;              a              .              count              #=> five              a              .              folio              (              1              )              .              per              (              20              )              .              size              #=> 20              a              .              page              (              one              )              .              per              (              20              )              .              total_count              #=> chiliad

The `padding` Scope

Occasionally yous need to pad a number of records that is not a multiple of the page size.

              User              .              order              (              :proper name              )              .              page              (              7              )              .              per              (              fifty              )              .              padding              (              three              )

Note that the padding scope as well is not directly divers on the models.

Unscoping

If for some reason yous need to unscope page and per methods you lot tin call except(:limit, :offset)

              users              =              User              .              order              (              :proper name              )              .              page              (              seven              )              .              per              (              l              )              unpaged_users              =              users              .              except              (              :limit              ,              :offset              )              # unpaged_users will not apply the kaminari scopes

Configuring Kaminari

General Configuration Options

Yous can configure the following default values past overriding these values using Kaminari.configure method.

              default_per_page      # 25 by default max_per_page          # nil past default max_pages             # nil by default window                # four by default outer_window          # 0 by default left                  # 0 by default correct                 # 0 past default page_method_name      # :page past default param_name            # :folio by default params_on_first_page  # faux 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 kaminari:config

Changing `page_method_name`

You lot tin can change the method proper noun page to bonzo or plant or whatever you similar, in order to play nice with existing folio method or association or telescopic or any other plugin that defines page method on your models.

Configuring Default per_page Value for Each Model by `paginates_per`

You can specify default per_page value per each model using the following declarative DSL.

              class              User              <              ActiveRecord::Base              paginates_per              l              terminate

Configuring Max per_page Value for Each Model by `max_paginates_per`

You can specify max per_page value per each model using the following declarative DSL. If the variable that specified via per scope is more than than this variable, max_paginates_per is used instead of it. Default value is zero, which means you are not imposing whatever max per_page value.

              class              User              <              ActiveRecord::Base              max_paginates_per              100              stop

Configuring max_pages Value for Each Model by `max_pages`

You can specify max_pages value per each model using the following declarative DSL. This value restricts the total number of pages that can be returned. Useful for setting limits on large collections.

              class              User              <              ActiveRecord::Base              max_pages              100              cease

Configuring params_on_first_page when using ransack_memory

If you are using the ransack_memory gem and experience problems navigating back to the previous or offset page, fix the params_on_first_page setting to truthful.

Controllers

The Folio Parameter Is in `params[:page]`

Typically, your controller code will look like this:

              @users              =              User              .              order              (              :name              )              .              folio              params              [              :page              ]

Views

The Same Former Helper Method

Only telephone call the paginate helper:

This volition return several ?page=N pagination links surrounded by an HTML5 <nav> tag.

Helpers

The `paginate` Helper Method

This would output several pagination links such every bit « First ‹ Prev ... 2 three 4 5 6 seven eight 9 x ... Side by side › Concluding »

Specifying the "inner window" Size (4 by default)

              <%=              paginate @users, window: 2              %>

This would output something like ... five 6 7 8 9 ... when 7 is the electric current page.

Specifying the "outer window" Size (0 past default)

              <%=              paginate @users, outer_window: 3              %>

This would output something like 1 2 iii ...(snip)... 18 19 20 while having 20 pages in full.

Outer Window Can Be Separately Specified by left, right (0 past default)

              <%=              paginate @users, left: ane, right: 3              %>

This would output something similar ane ...(snip)... 18 19 20 while having 20 pages in total.

Changing the Parameter Proper noun (`:param_name`) for the Links

              <%=              paginate @users, param_name: :pagina              %>

This would modify the query parameter proper name on each links.

Actress Parameters (`:params`) for the Links

              <%=              paginate @users, params: {controller: 'foo', action: 'bar', format: :turbo_stream}              %>

This would modify each link's url_option. :controller and :activity might be the keys in common.

Ajax Links (crazy simple, but works perfectly!)

              <%=              paginate @users, remote: true              %>

This would add data-remote="true" to all the links inside.

Specifying an Alternative Views Directory (default is kaminari/)

              <%=              paginate @users, views_prefix: 'templates'              %>

This would search for partials in app/views/templates/kaminari. This option makes it easier to do things like A/B testing pagination templates/themes, using new/old templates at the same time besides as better integration with other gems such as cells.

The `link_to_next_page` and `link_to_previous_page` (aliased to `link_to_prev_page`) Helper Methods

              <%=              link_to_next_page @items, 'Next Page'              %>

This simply renders a link to the adjacent page. This would exist helpful for creating a Twitter-like pagination feature.

The helper methods support a params pick to farther specify the link. If format needs to be set up, inlude it in the params hash.

              <%=              link_to_next_page @items, 'Adjacent Page', params: {controller: 'foo', action: 'bar', format: :turbo_stream}              %>

The `page_entries_info` Helper Method

              <%=              page_entries_info @posts              %>

This renders a helpful message with numbers of displayed vs. total entries.

By default, the message will use the humanized class name of objects in collection: for instance, "projection types" for ProjectType models. The namespace will be cut out and only the last name will exist used. Override this with the :entry_name parameter:

              <%=              page_entries_info @posts, entry_name: 'item'              %>                                                                                    #=>              Displaying items 6 - 10 of 26 in total

The `rel_next_prev_link_tags` Helper Method

              <%=              rel_next_prev_link_tags @users              %>

This renders the rel next and prev link tags for the head.

The `path_to_next_page` Helper Method

              <%=              path_to_next_page @users              %>

This returns the server relative path to the side by side page.

The `path_to_prev_page` Helper Method

              <%=              path_to_prev_page @users              %>

This returns the server relative path to the previous page.

I18n and Labels

The default labels for 'showtime', 'last', 'previous', '...' and 'side by side' are stored in the I18n yaml inside the engine, and rendered through I18n API. You tin can switch the label value per I18n.locale for your internationalized awarding. Keys and the default values are the following. You can override them by adding to a YAML file in your Runway.root/config/locales directory.

              en:              views:              pagination:              offset:                              "&laquo; First"                            last:                              "Last &raquo;"                            previous:                              "&lsaquo; Prev"                            next:                              "Next &rsaquo;"                            truncate:                              "&hellip;"                            helpers:              page_entries_info:              one_page:              display_entries:              nil:                              "No %{entry_name} found"                            one:                              "Displaying <b>1</b> %{entry_name}"                            other:                              "Displaying <b>all %{count}</b> %{entry_name}"                            more_pages:              display_entries:                              "Displaying %{entry_name} <b>%{first}&nbsp;-&nbsp;%{terminal}</b> of <b>%{full}</b> in full"

If you use not-English localization come across i18n rules for changing one_page:display_entries block.

Customizing the Pagination Helper

Kaminari includes a handy template generator.

To Edit Your Paginator

Run the generator beginning,

% track yard kaminari:views default

and then edit the partials in your app'south app/views/kaminari/ directory.

For Haml/Slim Users

Yous tin utilize the html2haml gem or the html2slim gem to convert erb templates. The kaminari jewel will automatically pick up haml/slim templates if you place them in app/views/kaminari/.

Multiple Templates

In example you need different templates for your paginator (for example public and admin), y'all can pass --views-prefix directory like this:

% rails g kaminari:views default --views-prefix admin

that will generate partials in app/views/admin/kaminari/ directory.

Themes

The generator has the power to fetch several sample template themes from the external repository (https://github.com/amatsuda/kaminari_themes) in addition to the arranged "default" one, which volition help you creating a nice looking paginator.

% rails g kaminari:views THEME

To see the full list of available themes, take a await at the themes repository, or just hit the generator without specifying THEME argument.

Multiple Themes

To utilize multiple themes from within a single awarding, create a directory inside the app/views/kaminari/ and motility your custom template files into that directory.

% rails g kaminari:views default (skip              if              you have existing kaminari views) %              cd              app/views/kaminari % mkdir my_custom_theme % cp _*.html.*              my_custom_theme/

Next, reference that directory when calling the paginate method:

              <%=              paginate @users, theme: 'my_custom_theme'              %>

Customize away!

Notation: if the theme isn't nowadays or none is specified, kaminari will default dorsum to the views included inside the jewel.

Paginating Without Issuing SELECT COUNT Query

Generally the paginator needs to know the full number of records to display the links, just sometimes we don't need the full number of records and just need the "previous folio" and "adjacent page" links. For such use example, Kaminari provides without_count mode that creates a paginatable drove without counting the number of all records. This may be helpful when you lot're dealing with a very big dataset considering counting on a big table tends to go irksome on RDBMS.

Simply add .without_count to your paginated object:

              User              .              page              (              3              )              .              without_count

In your view file, you lot tin simply use simple helpers like the following instead of the full-featured paginate helper:

              <%=              link_to_prev_page @users, 'Previous Folio'              %>                            <%=              link_to_next_page @users, 'Side by side Page'              %>

Paginating a Generic Assortment object

Kaminari provides an Array wrapper class that adapts a generic Array object to the paginate view helper. However, the paginate helper doesn't automatically handle your Assortment object (this is intentional and past blueprint). Kaminari::paginate_array method converts your Array object into a paginatable Array that accepts page method.

              @paginatable_array              =              Kaminari              .              paginate_array              (              my_array_object              )              .              folio              (              params              [              :page              ]              )              .              per              (              10              )

You lot can specify the total_count value through options Hash. This would be helpful when handling an Array-ish object that has a unlike count value from actual count such every bit RSolr search result or when you need to generate a custom pagination. For case:

              @paginatable_array              =              Kaminari              .              paginate_array              (              [              ]              ,              total_count:              145              )              .              folio              (              params              [              :page              ]              )              .              per              (              10              )

or, in the instance of using an external API to source the page of data:

              page_size              =              10              one_page              =              get_page_of_data              params              [              :page              ]              ,              page_size              @paginatable_array              =              Kaminari              .              paginate_array              (              one_page              .              data              ,              total_count:              one_page              .              total_count              )              .              page              (              params              [              :page              ]              )              .              per              (              page_size              )

Creating Friendly URLs and Caching

Because of the page parameter and Rails routing, you can easily generate SEO and user-friendly URLs. For any resource you'd similar to paginate, merely add the following to your routes.rb:

              resource              :my_resources              do              get              'page/:page'              ,              action:              :index              ,              on:              :collection              end

If y'all are using Rails 4 or later, you can simplify route definitions by using business organization:

              concern              :paginatable              practise              become              '(folio/:page)'              ,              action:              :alphabetize              ,              on:              :collection              ,              as:              ''              end              resources              :my_resources              ,              concerns:              :paginatable

This will create URLs like /my_resources/folio/33 instead of /my_resources?folio=33. This is now a friendly URL, but it also has other added benefits...

Because the page parameter is now a URL segment, we tin leverage on Rails page caching!

NOTE: In this example, I've pointed the route to my :index activity. You may have defined a custom pagination activity in your controller - y'all should point action: :your_custom_action instead.

Other Framework/Library Support

The kaminari gem

Technically, the kaminari gem consists of 3 private components:

              kaminari-core: the cadre pagination logic kaminari-activerecord: Active Record adapter kaminari-actionview: Action View adapter

So, bundling gem 'kaminari' is equivalent to the following 2 lines (kaminari-core is referenced from the adapters):

              precious stone              'kaminari-activerecord'              gem              'kaminari-actionview'

For Other ORM Users

If y'all want to use other supported ORMs instead of ActiveRecord, for example Mongoid, bundle its adapter instead of kaminari-activerecord.

              gem              'kaminari-mongoid'              precious stone              'kaminari-actionview'

Kaminari currently provides adapters for the following ORMs:

Agile Tape: https://github.com/kaminari/kaminari/tree/chief/kaminari-activerecord (included in this repo)
Mongoid: https://github.com/kaminari/kaminari-mongoid
MongoMapper: https://github.com/kaminari/kaminari-mongo_mapper
DataMapper: https://github.com/kaminari/kaminari-data_mapper (would not work on kaminari ane.0.ten)

For Other Web Framework Users

If y'all want to utilize other web frameworks instead of Rails + Action View, for example Sinatra, parcel its adapter instead of kaminari-actionview.

              gem              'kaminari-activerecord'              gem              'kaminari-sinatra'

Kaminari currently provides adapters for the post-obit web frameworks:

Activity View: https://github.com/kaminari/kaminari/tree/master/kaminari-actionview (included in this repo)
Sinatra: https://github.com/kaminari/kaminari-sinatra
Grape: https://github.com/kaminari/kaminari-grape

For More Data

Cheque out Kaminari recipes on the GitHub Wiki for more advanced tips and techniques. https://github.com/kaminari/kaminari/wiki/Kaminari-recipes

Questions, Feedback

Experience free to message me on Github (amatsuda) or Twitter (@a_matsuda) ☇☇☇ :)

Contributing to Kaminari

Fork, set up, then send a pull request.

To run the test suite locally confronting all supported frameworks:

% bundle install % rake examination:all

To target the test suite confronting one framework:

% rake test:active_record_50

Yous tin can find a listing of supported test tasks by running rake -T. You may as well find it useful to run a specific test for a specific framework. To exercise so, you'll accept to commencement make certain yous have bundled everything for that configuration, then you can run the specific examination:

% BUNDLE_GEMFILE=                'gemfiles/active_record_50.gemfile'                            parcel install % BUNDLE_GEMFILE=                'gemfiles/active_record_50.gemfile'                            Exam=kaminari-core/examination/requests/navigation_test.rb package              exec              rake              test