Class: Neo4j::Cypher::RelVar

Inherits:
Object
  • Object
show all
Includes:
Clause
Defined in:
lib/neo4j-cypher/rel_var.rb

Defined Under Namespace

Classes: EvalContext

Constant Summary

Constants included from Clause

Clause::NAME, Clause::ORDER

Instance Attribute Summary

Attributes included from Clause

#clause_list, #clause_type, #eval_context, #expr, #insert_order

Instance Method Summary collapse

Methods included from Clause

#<=>, #alias_name, #as_alias, #as_alias?, #clause_position, #create_clause_args_for, #match_value, #match_value=, #prefix, #referenced?, #separator, #to_prop_string, #valid_clause?, #var_name, #var_name=

Constructor Details

#initialize(clause_list, expr, props = nil) ⇒ RelVar

Returns a new instance of RelVar.



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# File 'lib/neo4j-cypher/rel_var.rb', line 7

def initialize(clause_list, expr, props = nil)
  super(clause_list, :rel_var, EvalContext)

  self.var_name = guess_var_name_from_string(expr.first) if expr.first.is_a?(String)

  if props
    @match_value = "#{match_value_from_args(expr)} #{to_prop_string(props)}"
  else
    @match_value = match_value_from_args(expr)
  end
end

Instance Method Details

#guess_var_name_from_string(expr) ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 32

def guess_var_name_from_string(expr)
  guess = /([[:alpha:]_]*)/.match(expr)[1]
  guess && !guess.empty? && guess
end

#match_value_from_args(expr) ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 19

def match_value_from_args(expr)
  if expr.first.is_a?(String)
    expr.first
  elsif expr.first.is_a?(Symbol)
    ":#{expr.map { |e| match_value_from_symbol(e) }.join('|')}"
  elsif expr.empty?
    '?'
  else
    # try to join several RelVars to one rel var
    ":#{expr.map { |e| e.clause.rel_type }.join('|')}"
  end
end

#match_value_from_symbol(expr) ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 37

def match_value_from_symbol(expr)
  "`#{expr}`"
end

#optionally! ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 54

def optionally!
  if @match_value.include?('?')
    # We are done
  elsif @match_value.include?(':')
    @match_value.sub!(/:/, "?:")
  else
    @match_value += '?'
  end
  self
end

#referenced! ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 45

def referenced!
  eval_context.as(var_name) unless referenced?
  super
end

#rel_type ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 41

def rel_type
  @match_value.include?(':') ? @match_value.split(':').last : @match_value.sub('?', '')
end

#return_value ⇒ Object 



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# File 'lib/neo4j-cypher/rel_var.rb', line 50

def return_value
  var_name
end