Module: Pirate

Defined in:
lib/pirate.rb

Constant Summary collapse

@@result =

:redirect => ‘exact’ || ‘partial’ || ‘levenshtein’ || nil

{ :redirect => nil, :instance => nil, :stores => [], :coupons => [], :tags => [], :notice => nil }
@@tag_enabled = 
false
@@store_per_page = 
4
@@coupon_per_page = 
10
@@page = 
{ :stores => 1, :coupons => 1 }

Class Method Summary collapse

Class Method Details

.calculate_stores_by_match(query) ⇒ Object 



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# File 'lib/pirate.rb', line 120

def self.calculate_stores_by_match(query)
  # Misspelling Match -- search term is a misspelling of the store name
  # create Levenshtein matcher for our user's query, with only alphanumerics
  # downcase each store name and remove non-alphanumeric characters, then match em, and pick the minimum. 
  m = Amatch::Levenshtein.new(query)
  
  #             select only names            make an array of names      
  store_names = Store.active.all(:select => 'id, name').collect { |s| [s.id, s.name.gsub(/[^\w]/, '')] }
  
  #             array of pairs: [ levdistance, name ]         take maximum
  return store_names.collect { |n| [ m.match(n[1].downcase.gsub(/[^\w]/, '')), n[0], n[1] ] }
end

.calculate_stores_by_similarity(query) ⇒ Object 



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# File 'lib/pirate.rb', line 110

def self.calculate_stores_by_similarity(query)
  m = Amatch::Levenshtein.new(query)
  
  #             select only names            make an array of names      
  store_names = Store.active.all(:select => 'id, name').collect { |s| [s.id, s.name.gsub(/[^\w]/, '')] }
  
  #             array of pairs: [ levdistance, name ]         take maximum
  return store_names.collect { |n| [ m.similar(n[1].downcase.gsub(/[^\w]/, '')), n[0], n[1] ] }
end

.exact_match_redirects(query) ⇒ Object 



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# File 'lib/pirate.rb', line 47

def self.exact_match_redirects(query)
  reset_result
  
  # to force a search page and avoid redirection, add ?no_redirect=true to your url
  # Case Insensitive Match -- try to match store by near-exact name or domain match
  foundstores = Store.active.find(:all, :conditions => [ "LOWER(name) = ? or LOWER(homepage) LIKE ?", query.downcase, "%#{query.downcase}" ] )
  if !foundstores.nil? and foundstores.length == 1
    @@result = { :redirect => 'exact', :instance => foundstores.first } and return
  end
  
  if @@tag_enabled
    foundtags = Tag.find(:all, :conditions => [ "LOWER(name) = ?", query.downcase ] )
    if !foundtags.nil? and foundtags.length == 1
      @@result = { :redirect => 'exact', :instance => foundtags.first } and return
    end
  end

  # Partial Match -- a known store name or tag name exists within the search query
  foundstores = Store.active.find(:all, :conditions => [ "? LIKE CONCAT('%',LOWER(name),'%')", query.downcase ])
  if !foundstores.nil? and foundstores.length == 1
    store = foundstores.first
    @@result = { :redirect => 'partial', :instance => store, 
                 :notice =>  "We matched your search to &quot;#{store.name}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>" }
    return
  end
  
  # I don't think we need this, partial match in Tag is confusing users
  #if @@tag_enabled
  #  foundtags = Tag.find(:all, :conditions => [ "? LIKE CONCAT('%',LOWER(name),'%')", query.downcase ])
  #  if !foundtags.nil? and foundtags.length == 1
  #     @@result = { :redirect => 'partial', :instance => foundtags.first, 
  #                   :notice =>  "We matched your search to &quot;#{foundtags.first}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>" }
  #  end
  #end
end

.find(search_params) ⇒ Object 



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# File 'lib/pirate.rb', line 26

def self.find(search_params)   
  reset_result 
  @query = search_params[:searchInput]
  
  if search_params[:no_redirect].nil?
    exact_match_redirects(@query)
    levenshtein_search_stores_redirect(@query) unless @@result[:redirect]
    levenshtein_search_tags_redirect(@query) if @@tag_enabled && !@@result[:redirect]
  end
  
  if @@result[:redirect].nil?
    @@page[search_params[:cat].to_sym] = search_params[:page] if search_params[:cat] && search_params[:page]
    
    @@result[:stores]  = Store.active.remove_punct_from_name(@query.downcase).paginate(:per_page => @@store_per_page, :page => @@page[:stores])
    @@result[:coupons] = Coupon.active.ordered.name_or_store_name_or_description_like(@query).paginate(:per_page => @@coupon_per_page, :page => @@page[:coupons])
    @@result[:tags]    = Coupon.related_tags(@query) if @@tag_enabled
  end
  
  return @@result
end

.levenshtein_search_stores_redirect(query) ⇒ Object 



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# File 'lib/pirate.rb', line 83

def self.levenshtein_search_stores_redirect(query)
  reset_result
  
  lowquery = query.downcase.gsub(/[^\w]/, '')
  
  foundstores = calculate_stores_by_similarity(lowquery)
  foundstore = foundstores.max
  if !foundstore.nil? && foundstore[0] > 0.5
    store = Store.active.find(foundstore[1])
    @@result = { :redirect => 'levenshtein', :instance => store,
                 :notice => "We matched your search to &quot;#{store.name}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>"
               }
    return
  end
  
  maxdist = (lowquery.length / 4).to_i
  foundstores = calculate_stores_by_match(lowquery)
  foundstore = foundstores.min
  if !foundstore.nil? && foundstore[0] <= maxdist
    store = Store.active.find(foundstore[1])
    @@result = { :redirect => 'levenshtein', :instance => store,
                 :notice => "We matched your search to &quot;#{store.name}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>"
               }
    return
  end
end

.levenshtein_search_tags_redirect(query) ⇒ Object 



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# File 'lib/pirate.rb', line 133

def self.levenshtein_search_tags_redirect(query)
  reset_result
  
  # Misspelling Match -- search term is a misspelling of the store name
  # create Levenshtein matcher for our user's query, with only alphanumerics
  # downcase each store name and remove non-alphanumeric characters, then match em, and pick the minimum. 
  
  lowquery = query.downcase.gsub(/[^\w]/, '')
  m = Amatch::Levenshtein.new(lowquery)
  tag_names = Tag.all(:select => 'name').collect { |t| t.name }
  
  foundtag = tag_names.collect { |n| [ m.similar(n.downcase.gsub(/[^\w]/, '')), n ] }.max
  if !foundtag.nil? && foundtag[0] > 0.5
    tag = Tag.find_by_name(foundtag[1])
    @@result = { :redirect => 'levenshtein', :instance => tag,
                 :notice => "We matched your search to &quot;#{tag.name}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>"
               }
    return
  end
  
  maxdist = (lowquery.length / 4).to_i
  #                   select only names            make an array of names      array of pairs: [ levdistance, name ]         take minimum
  foundtag = tag_names.collect { |n| [ m.match(n.downcase.gsub(/[^\w]/, '')), n ] }.min
  if !foundtag.nil? and foundtag[0] <= maxdist
    tag = Tag.find_by_name(foundtag[1])
    @@result = { :redirect => 'levenshtein', :instance => tag,
                 :notice => "We matched your search to &quot;#{tag.name}&quot;.  Search instead for <a href='/searches/new?searchInput=#{URI.escape(query)}&no_redirect=true'>#{query}</a>"
               }
    return
  end
end

.reset_result ⇒ Object 



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# File 'lib/pirate.rb', line 22

def self.reset_result
  @@result = { :redirect => nil, :instance => nil, :stores => [], :coupons => [], :tags => [], :notice => nil }
end