Class: Ole::Storage::MetaData

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/ole/storage/meta_data.rb

Overview

The MetaData class is designed to be high level interface to all the underlying meta data stored within different sections, themselves within different property set streams.

With this class, you can simply get properties using their names, without needing to know about the underlying guids, property ids etc.

Example:

Ole::Storage.open('test.doc') { |ole| p ole.meta_data.doc_author }

TODO:

  • add write support
  • fix some of the missing type coercion (eg FileTime)
  • maybe add back the ability to access individual property sets as a unit directly. ie ole.summary_information. Is this useful?
  • full key support, for unknown keys, like ole.meta_data[myguid, myid]. probably needed for user-defined properties too.

Constant Summary collapse

FILE_MAP = 
{
  Types::PropertySet::FMTID_SummaryInformation => "\005SummaryInformation",
  Types::PropertySet::FMTID_DocSummaryInfo => "\005DocumentSummaryInformation"
}
FORMAT_MAP = 
{
  'MSWordDoc' => :doc
}
CLSID_EXCEL97 = 
Types::Clsid.parse "{00020820-0000-0000-c000-000000000046}"
CLSID_EXCEL95 = 
Types::Clsid.parse "{00020810-0000-0000-c000-000000000046}"
CLSID_WORD97 = 
Types::Clsid.parse "{00020906-0000-0000-c000-000000000046}"
CLSID_WORD95 = 
Types::Clsid.parse "{00020900-0000-0000-c000-000000000046}"
CLSID_MAP = 
{
  CLSID_EXCEL97 => :xls,
  CLSID_EXCEL95 => :xls,
  CLSID_WORD97  => :doc,
  CLSID_WORD95  => :doc
}
MIME_TYPES = 
{
  :xls => 'application/vnd.ms-excel',
  :doc => 'application/msword',
  :ppt => 'application/vnd.ms-powerpoint',
  # not registered at IANA, but seems most common usage
  :msg => 'application/vnd.ms-outlook',
  # this is my default fallback option. also not registered at IANA.
  # file(1)'s default is application/msword, which is useless...
  nil  => 'application/x-ole-storage'
}

Instance Method Summary collapse

Methods included from Enumerable

#group_by, #sum

Constructor Details

#initialize(ole) ⇒ MetaData

Returns a new instance of MetaData.



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# File 'lib/ole/storage/meta_data.rb', line 64

def initialize ole
  @ole = ole
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(name, *args, &block) ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 138

def method_missing name, *args, &block
  return super unless args.empty?
  return super unless Types::PropertySet::PROPERTY_MAP[name.to_s]
  self[name]
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 116

def [] key
  pair = Types::PropertySet::PROPERTY_MAP[key.to_s] or return nil
  file = FILE_MAP[pair.first] or return nil
  dirent = @ole.root[file] or return nil
  dirent.open { |io| return Types::PropertySet.new(io)[key] }
end

#[]=(key, value) ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/ole/storage/meta_data.rb', line 123

def []= key, value
  raise NotImplementedError, 'meta data writes not implemented'
end

#each(&block) ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 127

def each(&block)
  FILE_MAP.values.each do |file|
    dirent = @ole.root[file] or next
    dirent.open { |io| Types::PropertySet.new(io).each(&block) }
  end
end

#file_format ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 94

def file_format
  comp_obj[:file_format]
end

#mime_type ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 98

def mime_type
  # based on the CompObj stream contents
  type = FORMAT_MAP[file_format]
  return MIME_TYPES[type] if type

  # based on the root clsid
  type = CLSID_MAP[Types::Clsid.load(@ole.root.clsid)]
  return MIME_TYPES[type] if type

  # fallback to heuristics
  has_file = Hash[*@ole.root.children.map { |d| [d.name.downcase, true] }.flatten]
  return MIME_TYPES[:msg] if has_file['__nameid_version1.0'] or has_file['__properties_version1.0']
  return MIME_TYPES[:doc] if has_file['worddocument'] or has_file['document']
  return MIME_TYPES[:xls] if has_file['workbook'] or has_file['book']

  MIME_TYPES[nil]
end

#to_h ⇒ Object 



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# File 'lib/ole/storage/meta_data.rb', line 134

def to_h
  inject({}) { |hash, (name, value)| hash.update name.to_sym => value }
end