Class: RelaxDB::Paginator

Inherits:
Object
  • Object
show all
Defined in:
lib/relaxdb/paginator.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(paginate_params, page_params) ⇒ Paginator

Returns a new instance of Paginator.



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# File 'lib/relaxdb/paginator.rb', line 7

def initialize(paginate_params, page_params)
  @paginate_params = paginate_params
  @orig_paginate_params = @paginate_params.clone
  
  page_params = page_params.is_a?(String) ? JSON.parse(page_params).to_mash : page_params
  # Where the magic happens - the original params are updated with the page specific params
  @paginate_params.update(page_params)
end

Instance Attribute Details

#paginate_params ⇒ Object (readonly)

Returns the value of attribute paginate_params.



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# File 'lib/relaxdb/paginator.rb', line 5

def paginate_params
  @paginate_params
end

Instance Method Details

#add_next_and_prev(docs, design_doc, view_name, view_keys) ⇒ Object 



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# File 'lib/relaxdb/paginator.rb', line 25

def add_next_and_prev(docs, design_doc, view_name, view_keys)
  unless docs.empty?
    no_docs = docs.size
    offset = docs.offset
    orig_offset = orig_offset(design_doc, view_name)
    total_doc_count = total_doc_count(design_doc, view_name)      
  
    next_exists = !@paginate_params.order_inverted? ? (offset - orig_offset + no_docs < total_doc_count) : true
    next_params = create_next(docs.last, view_keys) if next_exists

    prev_exists = @paginate_params.order_inverted? ? (offset - orig_offset + no_docs < total_doc_count) : 
      (offset - orig_offset == 0 ? false : true)
    prev_params = create_prev(docs.first, view_keys) if prev_exists
  else
    next_exists = prev_exists = false
  end
  
  docs.meta_class.instance_eval do        
    define_method(:next_params) { next_exists ? next_params : false }
    define_method(:next_query) { next_exists ? "page_params=#{::CGI::escape(next_params.to_json)}" : false }
    
    define_method(:prev_params) { prev_exists ? prev_params : false }
    define_method(:prev_query) { prev_exists ? "page_params=#{::CGI::escape(prev_params.to_json)}" : false }
  end      
end

#create_next(doc, view_keys) ⇒ Object 



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# File 'lib/relaxdb/paginator.rb', line 51

def create_next(doc, view_keys)
  next_key = view_keys.map { |a| doc.send(a) }
  next_key = next_key.length == 1 ? next_key[0] : next_key
  next_key_docid = doc._id
  { :startkey => next_key, :startkey_docid => next_key_docid, :descending => @orig_paginate_params.descending }
end

#create_prev(doc, view_keys) ⇒ Object 



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# File 'lib/relaxdb/paginator.rb', line 58

def create_prev(doc, view_keys)
  prev_key = view_keys.map { |a| doc.send(a) }
  prev_key = prev_key.length == 1 ? prev_key[0] : prev_key
  prev_key_docid = doc._id
  prev_params = { :startkey => prev_key, :startkey_docid => prev_key_docid, :descending => !@orig_paginate_params.descending }
end

#orig_offset(design_doc, view_name) ⇒ Object 



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# File 'lib/relaxdb/paginator.rb', line 65

def orig_offset(design_doc, view_name)
  query = Query.new(design_doc, view_name)
  if @paginate_params.order_inverted?
    query.startkey(@orig_paginate_params.endkey).descending(!@orig_paginate_params.descending)
  else
    query.startkey(@orig_paginate_params.startkey).descending(@orig_paginate_params.descending)
  end
  query.reduce(false).limit(1)
  RelaxDB.retrieve(query.view_path).offset
end

#total_doc_count(design_doc, view_name) ⇒ Object 



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# File 'lib/relaxdb/paginator.rb', line 16

def total_doc_count(design_doc, view_name)
  result = RelaxDB.view(design_doc, view_name) do |q|
    q.reduce(true)
    q.startkey(@orig_paginate_params.startkey).endkey(@orig_paginate_params.endkey).descending(@orig_paginate_params.descending)  
  end
  
  total_docs = RelaxDB.reduce_result(result)
end