Class: ZAWS::Helper::IniFile::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/zaws/helper/inifile.rb

Overview

The IniFile::Parser has the responsibility of reading the contents of an .ini file and storing that information into a ruby Hash. The object being parsed must respond to ‘each_line` - this includes Strings and any IO object.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hash, param, comment, default) ⇒ Parser

Create a new IniFile::Parser that can be used to parse the contents of an .ini file.

hash - The Hash where parsed information will be stored param - String used to separate parameter and value comment - String containing the comment character(s) default - The String name of the default global section



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# File 'lib/zaws/helper/inifile.rb', line 425

def initialize( hash, param, comment, default )
  @hash = hash
  @default = default

  comment = comment.to_s.empty? ? "\\z" : "\\s*(?:[#{comment}].*)?\\z"

  @section_regexp  = %r/\A\s*\[([^\]]+)\]#{comment}/
  @ignore_regexp   = %r/\A#{comment}/
  @property_regexp = %r/\A(.*?)(?<!\\)#{param}(.*)\z/

  @open_quote      = %r/\A\s*(".*)\z/
  @close_quote     = %r/\A(.*(?<!\\)")#{comment}/
  @full_quote      = %r/\A\s*(".*(?<!\\)")#{comment}/
  @trailing_slash  = %r/\A(.*)(?<!\\)\\#{comment}/
  @normal_value    = %r/\A(.*?)#{comment}/
end

Instance Attribute Details

#property ⇒ Object

Returns the value of attribute property.



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# File 'lib/zaws/helper/inifile.rb', line 414

def property
  @property
end

#section ⇒ Object

Returns the current section Hash.



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# File 'lib/zaws/helper/inifile.rb', line 570

def section
  @section ||= @hash[@default]
end

#value ⇒ Object

Returns the value of attribute value.



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# File 'lib/zaws/helper/inifile.rb', line 415

def value
  @value
end

Instance Method Details

#error(msg = 'Could not parse line') ⇒ Object

Raise a parse error using the given message and appending the current line being parsed.

msg - The message String to use.

Raises IniFile::Error

Raises:



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# File 'lib/zaws/helper/inifile.rb', line 580

def error( msg = 'Could not parse line' )
  raise Error, "#{msg}: #{@line.inspect}"
end

#leading_quote? ⇒ Boolean

Returns ‘true` if the current value starts with a leading double quote. Otherwise returns false.

Returns:

  • (Boolean) 


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# File 'lib/zaws/helper/inifile.rb', line 444

def leading_quote?
  value && value =~ %r/\A"/
end

#parse(content) ⇒ Object

Parse the ini file contents. This will clear any values currently stored in the ini hash.

content - Any object that responds to ‘each_line`

Returns nil.



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# File 'lib/zaws/helper/inifile.rb', line 509

def parse( content )
  return unless content

  continuation = false

  @hash.clear
  @line = nil
  self.section = nil

  content.each_line do |line|
    @line = line.chomp

    if continuation
      continuation = parse_value @line
    else
      case @line
        when @ignore_regexp
          nil
        when @section_regexp
          self.section = @hash[$1]
        when @property_regexp
          self.property = $1.strip
          error if property.empty?

          continuation = parse_value $2
        else
          error
      end
    end
  end

  # check here if we have a dangling value ... usually means we have an
  # unmatched open quote
  if leading_quote?
    error "Unmatched open quote"
  elsif property && value
    process_property
  elsif value
    error
  end

  nil
end

#parse_value(string) ⇒ Object

Given a string, attempt to parse out a value from that string. This value might be continued on the following line. So this method returns ‘true` if it is expecting more data.

string - String to parse

Returns ‘true` if the next line is also part of the current value. Returns `fase` if the string contained a complete value.



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# File 'lib/zaws/helper/inifile.rb', line 456

def parse_value( string )
  continuation = false

  # if our value starts with a double quote, then we are in a
  # line continuation situation
  if leading_quote?
    # check for a closing quote at the end of the string
    if string =~ @close_quote
      value << $1

      # otherwise just append the string to the value
    else
      value << string
      continuation = true
    end

    # not currently processing a continuation line
  else
    case string
      when @full_quote
        self.value = $1

      when @open_quote
        self.value = $1
        continuation = true

      when @trailing_slash
        self.value ?  self.value << $1 : self.value = $1
        continuation = true

      when @normal_value
        self.value ?  self.value << $1 : self.value = $1

      else
        error
    end
  end

  if continuation
    self.value << $/ if leading_quote?
  else
    process_property
  end

  continuation
end

#process_property ⇒ Object

Store the property/value pair in the currently active section. This method checks for continuation of the value to the next line.

Returns nil.



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# File 'lib/zaws/helper/inifile.rb', line 557

def process_property
  property.strip!
  value.strip!

  self.value = $1 if value =~ %r/\A"(.*)(?<!\\)"\z/m

  section[property] = typecast(value)

  self.property = nil
  self.value = nil
end

#typecast(value) ⇒ Object

Attempt to typecast the value string. We are looking for boolean values, integers, floats, and empty strings. Below is how each gets cast, but it is pretty logical and straightforward.

"true"  -->  true
"false" -->  false
""      -->  nil
"42"    -->  42
"3.14"  -->  3.14
"foo"   -->  "foo"

Returns the typecast value.



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# File 'lib/zaws/helper/inifile.rb', line 596

def typecast( value )
  case value
    when %r/\Atrue\z/i;  true
    when %r/\Afalse\z/i; false
    when %r/\A\s*\z/i;   nil
    else
      Integer(value) rescue \
    Float(value)   rescue \
    unescape_value(value)
  end
end

#unescape_value(value) ⇒ Object

Unescape special characters found in the value string. This will convert escaped null, tab, carriage return, newline, and backslash into their literal equivalents.

value - The String value to unescape.

Returns the unescaped value.



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# File 'lib/zaws/helper/inifile.rb', line 615

def unescape_value( value )
  value = value.to_s
  value.gsub!(%r/\\[0nrt\\]/) { |char|
    case char
      when '\0';   "\0"
      when '\n';   "\n"
      when '\r';   "\r"
      when '\t';   "\t"
      when '\\\\'; "\\"
    end
  }
  value
end