Class: SearchApi::TextCriterion

Inherits:
Object
  • Object
show all
Defined in:
lib/search_api/text_criterion.rb

Overview

Utility class that implements fulltext search.

Includes some Google-like features.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(inSearchString = '', inOptions = {}) ⇒ TextCriterion

Returns a new instance of TextCriterion.



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# File 'lib/search_api/text_criterion.rb', line 21

def initialize(inSearchString='', inOptions= {})
  # inOptions may contain :
  # :exclude => string, Regexp, or list of Strings and Regexp to exclude (strings are case insensitive)

  @options = inOptions
  @options[:exclude] = [@options[:exclude]] unless @options[:exclude].nil? || (@options[:exclude].is_a?(Enumerable) && !@options[:exclude].is_a?(String))
  @options[:parse_meta?] = true if @options[:parse_meta?].nil?

  @meta_keywords = {}
  @mandatory_keywords = []
  @negative_keywords = []
  @optional_keywords = []

  unless inSearchString.blank?

    currentMeta = nil
  
    splitter = /
          (
              [-+]?\b[^ ":]+\b:?
          )
          |
          (
              [-+]?"[^"]*"
          )
        /x

    inSearchString.gsub(/\s+/, ' ').scan(splitter).each { |keyword|
      keyword=(keyword[0]||keyword[1]).gsub(/"/, '')
  
      if currentMeta
        @meta_keywords[currentMeta] ||= []
        @meta_keywords[currentMeta] << keyword
        currentMeta = nil
      else
        case keyword
        when /^-/
          @negative_keywords << keyword[1..-1] unless exclude_keyword?(keyword[1..-1])
        when /^\+/
          @mandatory_keywords << keyword[1..-1] unless exclude_keyword?(keyword[1..-1])
        when /:$/
          if @options[:parse_meta?]
            currentMeta = keyword[0..-2]
          else
            @optional_keywords << keyword unless exclude_keyword?(keyword)
          end
        else
          @optional_keywords << keyword unless exclude_keyword?(keyword)
        end
      end
    }

    # if everything is excluded, look for the whole search string
    @optional_keywords << inSearchString if @meta_keywords.empty? && @mandatory_keywords.empty? && @negative_keywords.empty? && @optional_keywords.empty?
  end
end

Instance Attribute Details

#mandatory_keywords ⇒ Object

Returns the value of attribute mandatory_keywords.



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# File 'lib/search_api/text_criterion.rb', line 17

def mandatory_keywords
  @mandatory_keywords
end

#meta_keywords ⇒ Object

Returns the value of attribute meta_keywords.



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# File 'lib/search_api/text_criterion.rb', line 16

def meta_keywords
  @meta_keywords
end

#negative_keywords ⇒ Object

Returns the value of attribute negative_keywords.



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# File 'lib/search_api/text_criterion.rb', line 18

def negative_keywords
  @negative_keywords
end

#optional_keywords ⇒ Object

Returns the value of attribute optional_keywords.



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# File 'lib/search_api/text_criterion.rb', line 19

def optional_keywords
  @optional_keywords
end

Instance Method Details

#condition(inFields) ⇒ Object 



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# File 'lib/search_api/text_criterion.rb', line 99

def condition(inFields)
  conditions = SqlFragment.new

  conditions << (@mandatory_keywords.inject(SqlFragment.new) { |cv, value|
    value = "%#{value}%"
    cv.and(inFields.inject(SqlFragment.new) { |cf, field|
      cf.or(["#{field} like ?", value])
    })
  })
  
  conditions << (@negative_keywords.inject(SqlFragment.new) { |cv, value|
    value = "%#{value}%"
    cv.and(inFields.inject(SqlFragment.new) { |cf, field|
      cf.or(["#{field} is not null AND #{field} like ?", value])
    })
  }.not)
  
  conditions << (@optional_keywords.inject(SqlFragment.new) { |cv, value|
    value = "%#{value}%"
    cv.or(inFields.inject(SqlFragment.new) { |cf, field|
      cf.or(["#{field} like ?", value])
    })
  })

  conditions
end

#positive_keywords ⇒ Object 



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# File 'lib/search_api/text_criterion.rb', line 95

def positive_keywords
  @mandatory_keywords + @optional_keywords
end

#to_s ⇒ Object 



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# File 'lib/search_api/text_criterion.rb', line 78

def to_s
  chunks = []
  chunks += @mandatory_keywords.map { |x| (x =~ / /) ? "+\"#{x}\"" : "+#{x}" } unless @mandatory_keywords.blank?
  chunks += @negative_keywords.map { |x| (x =~ / /) ? "-\"#{x}\"" : "-#{x}" } unless @negative_keywords.blank?
  chunks += @optional_keywords.map { |x| (x =~ / /) ? "\"#{x}\"" : x.to_s } unless @optional_keywords.blank?
  chunks += @meta_keywords.inject([]) { |s, key_value|
    key, value = key_value
    if value.is_a?(Array)
      s += value.map { |x| (x =~ / /) ? "#{key}:\"#{x}\"" : "#{key}:#{x}" }
    else
      s << ((value =~ / /) ? "#{key}:\"#{value}\"" : "#{key}:#{value}")
    end
    s
  } if @meta_keywords
  chunks.join(' ')
end