Class: ScopedSearch::AutoCompleteBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/scoped_search/auto_complete_builder.rb

Overview

The AutoCompleteBuilder class builds suggestions to complete query based on the query language syntax.

Constant Summary collapse

LOGICAL_INFIX_OPERATORS =
ScopedSearch::QueryLanguage::Parser::LOGICAL_INFIX_OPERATORS
LOGICAL_PREFIX_OPERATORS =
ScopedSearch::QueryLanguage::Parser::LOGICAL_PREFIX_OPERATORS
NULL_PREFIX_OPERATORS =
ScopedSearch::QueryLanguage::Parser::NULL_PREFIX_OPERATORS
NULL_PREFIX_COMPLETER =
['has']
COMPARISON_OPERATORS =
ScopedSearch::QueryLanguage::Parser::COMPARISON_OPERATORS
PREFIX_OPERATORS =
LOGICAL_PREFIX_OPERATORS + NULL_PREFIX_OPERATORS

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(definition, query, options) ⇒ AutoCompleteBuilder

Initializes the instance by setting the relevant parameters


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# File 'lib/scoped_search/auto_complete_builder.rb', line 25

def initialize(definition, query, options)
  @definition = definition
  @ast        = ScopedSearch::QueryLanguage::Compiler.parse(query)
  @query      = query
  @tokens     = tokenize
  @options    = options
end

Instance Attribute Details

#astObject (readonly)

Returns the value of attribute ast


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# File 'lib/scoped_search/auto_complete_builder.rb', line 14

def ast
  @ast
end

#definitionObject (readonly)

Returns the value of attribute definition


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# File 'lib/scoped_search/auto_complete_builder.rb', line 14

def definition
  @definition
end

#queryObject (readonly)

Returns the value of attribute query


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# File 'lib/scoped_search/auto_complete_builder.rb', line 14

def query
  @query
end

#tokensObject (readonly)

Returns the value of attribute tokens


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# File 'lib/scoped_search/auto_complete_builder.rb', line 14

def tokens
  @tokens
end

Class Method Details

.auto_complete(definition, query, options = {}) ⇒ Object

This method will parse the query string and build suggestion list using the search query.


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# File 'lib/scoped_search/auto_complete_builder.rb', line 18

def self.auto_complete(definition, query, options = {})
  return [] if (query.nil? or definition.nil? or !definition.respond_to?(:fields))

  new(definition, query, options).build_autocomplete_options
end

Instance Method Details

#build_autocomplete_optionsObject

Test the validity of the current query and suggest possible completion


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# File 'lib/scoped_search/auto_complete_builder.rb', line 34

def build_autocomplete_options
  # First parse to find illegal syntax in the existing query,
  # this method will throw exception on bad syntax.
  is_query_valid

  # get the completion options
  node = last_node
  completion = complete_options(node)

  suggestions = []
  suggestions += complete_keyword        if completion.include?(:keyword)
  suggestions += LOGICAL_INFIX_OPERATORS if completion.include?(:logical_op)
  suggestions += LOGICAL_PREFIX_OPERATORS + NULL_PREFIX_COMPLETER if completion.include?(:prefix_op)
  suggestions += complete_operator(node) if completion.include?(:infix_op)
  suggestions += complete_value          if completion.include?(:value)

  build_suggestions(suggestions, completion.include?(:value))
end

#build_suggestions(suggestions, is_value) ⇒ Object


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# File 'lib/scoped_search/auto_complete_builder.rb', line 128

def build_suggestions(suggestions, is_value)
  return [] if (suggestions.blank?)

  q = query
  unless q =~ /(\s|\)|,)$/ || last_token_is(COMPARISON_OPERATORS)
    val = Regexp.escape(tokens.last.to_s).gsub('\*', '.*')
    suggestions = suggestions.map {|s| s if s.to_s =~ /^"?#{val}"?/i}.compact
    quoted = /("?#{Regexp.escape(tokens.last.to_s)}"?)$/.match(q)
    q.chomp!(quoted[1]) if quoted
  end

  # for dotted field names compact the suggestions list to be one suggestion
  # unless the user has typed the relation name entirely or the suggestion list
  # is short.
  last_token = tokens.last.to_s
  if (suggestions.size > 10 && (tokens.empty? || !last_token.include?('.')) && !is_value)
    suggestions = suggestions.map  do |s|
      !last_token.empty? && s.to_s.split('.')[0].end_with?(last_token) ? s.to_s : s.to_s.split('.')[0]
    end
  end

  suggestions.uniq.map {|m| "#{q} #{m}"}
end

#complete_date_valueObject

date value completer


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# File 'lib/scoped_search/auto_complete_builder.rb', line 231

def complete_date_value
  options = []
  options << '"30 minutes ago"'
  options << '"1 hour ago"'
  options << '"2 hours ago"'
  options << 'Today'
  options << 'Yesterday'
  options << 'Tomorrow'
  options << 2.days.ago.strftime('%A')
  options << 3.days.ago.strftime('%A')
  options << 4.days.ago.strftime('%A')
  options << 5.days.ago.strftime('%A')
  options << '"6 days ago"'
  options << 7.days.ago.strftime('"%b %d,%Y"')
  options << '"2 weeks from now"'
  options
end

#complete_key(name, field, val) ⇒ Object

this method completes the keys list in a key-value schema in the format table.keyName


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# File 'lib/scoped_search/auto_complete_builder.rb', line 168

def complete_key(name, field, val)
  return ["#{name}."] if !val || !val.is_a?(String) || !(val.include?('.'))
  val = val.sub(/.*\./,'')

  connection    = definition.klass.connection
  quoted_table  = field.key_klass.connection.quote_table_name(field.key_klass.table_name)
  quoted_field  = field.key_klass.connection.quote_column_name(field.key_field)
  field_name    = "#{quoted_table}.#{quoted_field}"

  field.key_klass
    .where(value_conditions(field_name, val))
    .select(field_name)
    .limit(20)
    .distinct
    .map(&field.key_field)
    .compact
    .map { |f| "#{name}.#{f} " }
end

#complete_key_value(field, token, val) ⇒ Object

complete values in a key-value schema


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# File 'lib/scoped_search/auto_complete_builder.rb', line 250

def complete_key_value(field, token, val)
  key_name = token.sub(/^.*\./,"")
  key_klass = field.key_klass.where(field.key_field => key_name).first
  raise ScopedSearch::QueryNotSupported, "Field '#{key_name}' not recognized for searching!" if key_klass.nil?

  query = completer_scope(field)

  if field.key_klass != field.klass
    key   = field.key_klass.to_s.gsub(/.*::/,'').underscore.to_sym
    fk    = definition.reflection_by_name(field.klass, key).association_foreign_key.to_sym
    query = query.where(fk => key_klass.id)
  end

  query
    .where(value_conditions(field.quoted_field, val))
    .select("DISTINCT #{field.quoted_field}")
    .limit(20)
    .map(&field.field)
    .compact
    .map { |v| v.to_s =~ /\s/ ? "\"#{v}\"" : v }
end

#complete_keywordObject

suggest all searchable field names. in relations suggest only the long format relation.field.


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# File 'lib/scoped_search/auto_complete_builder.rb', line 154

def complete_keyword
  keywords = []
  definition.fields.each do|f|
    next unless f[1].complete_enabled
    if (f[1].key_field)
      keywords += complete_key(f[0], f[1], tokens.last)
    else
      keywords << f[0].to_s + ' '
    end
  end
  keywords.sort
end

#complete_operator(node) ⇒ Object

This method complete infix operators by field type


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# File 'lib/scoped_search/auto_complete_builder.rb', line 278

def complete_operator(node)
  definition.operator_by_field_name(node.value).map { |o| o.end_with?(' ') ? o : "#{o} " }
end

#complete_options(node) ⇒ Object

parse the query and return the complete options


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# File 'lib/scoped_search/auto_complete_builder.rb', line 54

def complete_options(node)

  return [:keyword] + [:prefix_op] if tokens.empty?

  #prefix operator
  return [:keyword] if last_token_is(PREFIX_OPERATORS)

  # left hand
  if is_left_hand(node)
    if (tokens.size == 1 || last_token_is(PREFIX_OPERATORS + LOGICAL_INFIX_OPERATORS) ||
        last_token_is(PREFIX_OPERATORS + LOGICAL_INFIX_OPERATORS, 2))
      options = [:keyword]
      options += [:prefix_op]  unless last_token_is(PREFIX_OPERATORS)
    else
      options = [:logical_op]
    end
    return options
  end

  if is_right_hand
    # right hand
    return [:value]
  else
    # comparison operator completer
    return [:infix_op]
  end
end

#complete_set(field) ⇒ Object

set value completer


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# File 'lib/scoped_search/auto_complete_builder.rb', line 227

def complete_set(field)
  field.complete_value.keys
end

#complete_valueObject

this method auto-completes values of fields that have a :complete_value marker


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# File 'lib/scoped_search/auto_complete_builder.rb', line 188

def complete_value
  if last_token_is(COMPARISON_OPERATORS)
    token = tokens[tokens.size - 2]
    val = ''
  else
    token = tokens[tokens.size - 3]
    val = tokens[tokens.size - 1]
  end

  field = definition.field_by_name(token)
  return [] unless field && field.complete_value

  return complete_set(field) if field.set?
  return complete_date_value if field.temporal?
  return complete_key_value(field, token, val) if field.key_field

  special_values = field.special_values.select { |v| v =~ /\A#{val}/ }
  special_values + complete_value_from_db(field, special_values, val)
end

#complete_value_from_db(field, special_values, val) ⇒ Object


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# File 'lib/scoped_search/auto_complete_builder.rb', line 208

def complete_value_from_db(field, special_values, val)
  count = 20 - special_values.count
  completer_scope(field)
    .where(value_conditions(field.quoted_field, val))
    .select(field.quoted_field)
    .limit(count)
    .distinct
    .map(&field.field)
    .compact
    .map { |v| v.to_s =~ /\s/ ? "\"#{v.gsub('"', '\"')}\"" : v }
end

#completer_scope(field) ⇒ Object


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# File 'lib/scoped_search/auto_complete_builder.rb', line 220

def completer_scope(field)
  klass = field.klass
  scope =  klass.respond_to?(:completer_scope) ? klass.completer_scope(@options) : klass
  scope.respond_to?(:reorder) ? scope.reorder(field.quoted_field) : scope.scoped(:order => field.quoted_field)
end

#is_left_hand(node) ⇒ Object


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# File 'lib/scoped_search/auto_complete_builder.rb', line 90

def is_left_hand(node)
  field = definition.field_by_name(node.value) if node.respond_to?(:value)
  lh = field.nil? || field.key_field && !(query.end_with?(' '))
  lh = lh || last_token_is(NULL_PREFIX_OPERATORS, 2)
  lh = lh && !is_right_hand
  lh
end

#is_query_validObject

Test the validity of the existing query, this method will throw exception on illegal query syntax.


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# File 'lib/scoped_search/auto_complete_builder.rb', line 84

def is_query_valid
  # skip test for null prefix operators if in the process of completing the field name.
  return if(last_token_is(NULL_PREFIX_OPERATORS, 2) && !(query =~ /(\s|\)|,)$/))
  QueryBuilder.build_query(definition, query)
end

#is_right_handObject


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# File 'lib/scoped_search/auto_complete_builder.rb', line 98

def is_right_hand
  rh = last_token_is(COMPARISON_OPERATORS)
  if(tokens.size > 1 && !(query.end_with?(' ')))
    rh = rh || last_token_is(COMPARISON_OPERATORS, 2)
  end
  rh
end

#last_nodeObject


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# File 'lib/scoped_search/auto_complete_builder.rb', line 106

def last_node
  last = ast
  while (last.kind_of?(ScopedSearch::QueryLanguage::AST::OperatorNode) && !(last.children.empty?)) do
    last = last.children.last
  end
  last
end

#last_token_is(list, index = 1) ⇒ Object


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# File 'lib/scoped_search/auto_complete_builder.rb', line 114

def last_token_is(list,index = 1)
  if tokens.size >= index
    return list.include?(tokens[tokens.size - index])
  end
  return false
end

#tokenizeObject


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# File 'lib/scoped_search/auto_complete_builder.rb', line 121

def tokenize
  tokens = ScopedSearch::QueryLanguage::Compiler.tokenize(query)
  # skip parenthesis, it is not needed for the auto completer.
  tokens.delete_if {|t| t == :lparen || t == :rparen }
  tokens
end

#value_conditions(field_name, val) ⇒ Object

This method returns conditions for selecting completion from partial value


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# File 'lib/scoped_search/auto_complete_builder.rb', line 273

def value_conditions(field_name, val)
  val.blank? ? nil : "CAST(#{field_name} as CHAR(50)) LIKE '#{val.gsub("'","''")}%'".tr_s('%*', '%')
end