Class: SqlFormatter::Formatter

Inherits:
Object
  • Object
show all
Defined in:
lib/sql_formatter/formatter.rb

Constant Summary collapse

NEWLINE = 
"\n"
SPACE = 
" " * 1
TAB = 
" " * 2
COMMA = 
","
RESERVED_TOPLEVEL = 
[
  'select',
  'from',
  'where',
  'group by',
  'order by'
]
BOUNDARY = 
%w( , ; : ( ) . = < > + - * / ! ~ % | & # )
REGEX_RESERVED_TOPLEVEL = 
Regexp.new(RESERVED_TOPLEVEL.join('|').gsub(/ /, '\s+'))
REGEX_BOUNDARY = 
Regexp.new(BOUNDARY.map{ |m| Regexp.escape m }.join('|'))

Instance Method Summary collapse

Constructor Details

#initialize(string) ⇒ Formatter

Returns a new instance of Formatter.



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# File 'lib/sql_formatter/formatter.rb', line 22

def initialize(string)
  @ss       = StringScanner.new(string)
  @tokens   = []
  @space    = true
  @newline  = false
  @indent_level = 0
  @inline_parentheses = false
  @inline_parentheses_level = 0
  tokenize
  remove_space
end

Instance Method Details

#format ⇒ Object 



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# File 'lib/sql_formatter/formatter.rb', line 35

def format
  output = ''
  @tokens.each_with_index do |token, index|

    case

    # Reserved toplevel
    when  RESERVED_TOPLEVEL.include?(token)
      lower_indent_level
      output += NEWLINE if index > 0
      output += TAB * @indent_level

      # TODO: Add optional..
      if @indent_level >= 2
        @newline = false
      else
        @newline = true
      end

      raise_indent_level

    # End of tokens
    when token == ';' && index == (@tokens.size - 1)
      output += NEWLINE

    # Comma
    when token == COMMA
      @space = true

    # Left parenthesis
    when token == '('
      if @newline
        output += NEWLINE + TAB * @indent_level
      end

      if inline_left_parenthesis?(index)
        @newline = false
        @space = false
        @inline_parentheses = true
        @inline_parentheses_level += 1
        output += SPACE if @tokens[index - 1] == COMMA
      else
        @newline = true
        @indent_level += 2
        output += SPACE
      end

    # Right parenthesis
    when token == ')'
      if inline_right_parenthesis?
        @inline_parentheses_level = [0, @inline_parentheses_level - 1].max

        if @inline_parentheses_level == 0
          @inline_parentheses = false
          @space = true
        end
      else
        @indent_level -= 2
        output += NEWLINE + TAB
      end

    else
      if @inline_parentheses
        # Nothing to do
      elsif @newline
        output += NEWLINE + TAB * @indent_level
        @newline = false
      elsif @space
        output += SPACE
      else
        # Nothing to do
      end
    end

    output += token
  end
  output
end