Module: WillPaginate::Finders::ActiveRecord

Includes:
Base
Defined in:
lib/will_paginate/finders/active_record.rb

Overview

Paginating finders for ActiveRecord models

WillPaginate adds paginate, per_page and other methods to ActiveRecord::Base class methods and associations. It also hooks into method_missing to intercept pagination calls to dynamic finders such as paginate_by_user_id and translate them to ordinary finders (find_all_by_user_id in this case).

In short, paginating finders are equivalent to ActiveRecord finders; the only difference is that we start with “paginate” instead of “find” and that :page is required parameter:

@posts = Post.paginate :all, :page => params[:page], :order => 'created_at DESC'

In paginating finders, “all” is implicit. There is no sense in paginating a single record, right? So, you can drop the :all argument:

Post.paginate(...)              =>  Post.find :all
Post.paginate_all_by_something  =>  Post.find_all_by_something
Post.paginate_by_something      =>  Post.find_all_by_something

Instance Method Summary collapse

Methods included from Base

#paginate, #paginated_each, #per_page, #per_page=

Instance Method Details

#paginate_by_sql(sql, options) ⇒ Object

Wraps find_by_sql by simply adding LIMIT and OFFSET to your SQL string based on the params otherwise used by paginating finds: page and per_page.

Example:

@developers = Developer.paginate_by_sql ['select * from developers where salary > ?', 80000],
                       :page => params[:page], :per_page => 3

A query for counting rows will automatically be generated if you don’t supply :total_entries. If you experience problems with this generated SQL, you might want to perform the count manually in your application.



43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
 
# File 'lib/will_paginate/finders/active_record.rb', line 43

def paginate_by_sql(sql, options)
  WillPaginate::Collection.create(*wp_parse_options(options)) do |pager|
    query = sanitize_sql(sql.dup)
    original_query = query.dup
    # add limit, offset
    add_limit! query, :offset => pager.offset, :limit => pager.per_page
    # perfom the find
    pager.replace find_by_sql(query)
    
    unless pager.total_entries
      count_query = original_query.sub /\bORDER\s+BY\s+[\w`,\s]+$/mi, ''
      count_query = "SELECT COUNT(*) FROM (#{count_query})"
      
      unless ['oracle', 'oci'].include?(self.connection.adapter_name.downcase)
        count_query << ' AS count_table'
      end
      # perform the count query
      pager.total_entries = count_by_sql(count_query)
    end
  end
end

#respond_to?(method, include_priv = false) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


65
66
67
 
# File 'lib/will_paginate/finders/active_record.rb', line 65

def respond_to?(method, include_priv = false) #:nodoc:
  super(method.to_s.sub(/^paginate/, 'find'), include_priv)
end