Module: Spreadsheet::Excel::Reader::Biff8

Includes:
Internals
Defined in:
lib/spreadsheet/excel/reader/biff8.rb

Overview

of Excel grows and methods get moved here for disambiguation.

Constant Summary

Constants included from Internals

Internals::BINARY_FORMATS, Internals::BUILTIN_FORMATS, Internals::BUILTIN_STYLES, Internals::CODEPAGES, Internals::COLOR_CODES, Internals::EIGHT_BYTE_DOUBLE, Internals::ESCAPEMENT_TYPES, Internals::FONT_ENCODINGS, Internals::FONT_FAMILIES, Internals::FONT_WEIGHTS, Internals::LEAP_ERROR, Internals::NGILA_H_FX, Internals::NGILA_V_FX, Internals::NOITCERID_TXET_FX, Internals::OPCODES, Internals::OPCODE_SIZE, Internals::ROW_HEIGHT, Internals::SEDOCPO, Internals::SEDOC_ROLOC, Internals::SEGAPEDOC, Internals::SEILIMAF_TNOF, Internals::SEPYT_ENILREDNU, Internals::SEPYT_TNEMEPACSE, Internals::SGNIDOCNE_TNOF, Internals::SST_CHUNKSIZE, Internals::TWIPS, Internals::UNDERLINE_TYPES, Internals::XF_H_ALIGN, Internals::XF_TEXT_DIRECTION, Internals::XF_V_ALIGN

Instance Method Summary collapse

Methods included from Internals

#binfmt, #opcode

Instance Method Details

#continue_sst(work, oppos, len) ⇒ Object

Read more data into the Shared String Table. (see also: #read_sst) This method only evaluates the header, the actual work is done in #_read_sst



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 55

def continue_sst work, oppos, len
  pos = 0
  if @incomplete_sst
    pos = continue_string_header work, oppos
  elsif !@incomplete_skip.nil?
    pos =  @incomplete_skip
    @incomplete_skip = nil
  end
  @sst_offset[1] += len
  _read_sst work, oppos, pos
end

#continue_string(work, incomplete_string = @incomplete_string) ⇒ Object

When a String is too long for one Opcode, it is continued in a Continue Opcode. Excel may reconsider compressing the remainder of the string. This method appends the available remainder (decompressed if necessary) to the incomplete string.



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 15

def continue_string work, incomplete_string=@incomplete_string
  opts, _ = work.unpack 'C'
  wide = opts & 1
  head, chars = incomplete_string
  owing = chars - head.size / 2
  size = owing * (wide + 1)
  string = work[1, size]
  if wide == 0
    string = wide string
  end
  head << string
  if head.size >= chars * 2
    @incomplete_string = nil
  end
  size + 1
end

#continue_string_header(work, oppos) ⇒ Object

When a String is too long for one Opcode, it is continued in a Continue Opcode. Excel may reconsider compressing the remainder of the string. This method only evaluates the header and registers the address of the continuation with the previous SstEntry.



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 36

def continue_string_header work, oppos
  opts, _ = work.unpack 'C'
  wide = opts & 1
  owing = @incomplete_sst.continued_chars
  size = [work.size, owing * (1 + wide) + 1].min
  chars = (size - 1) / (1 + wide)
  skip = size
  @incomplete_sst.continue oppos + OPCODE_SIZE, size, chars
  unless @incomplete_sst.continued?
    @workbook.add_shared_string @incomplete_sst
    skip += @incomplete_skip
    @incomplete_sst = nil
    @incomplete_skip = nil
  end
  skip
end

#postread_workbook ⇒ Object

:nodoc:



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 66

def postread_workbook # :nodoc:
  super
  @incomplete_string, @sst_size, @sst_offset, @incomplete_sst = nil, @incomplete_skip = nil
end

#read_extsst(work, pos, len) ⇒ Object

Store the offset of extsst, so we can write a new extsst when the sst has changed



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 73

def read_extsst work, pos, len
  @workbook.offsets.store :extsst, [pos, len]
end

#read_sst(work, pos, len) ⇒ Object

Read the Shared String Table present in all Biff8 Files. This method only evaluates the header, the actual work is done in #_read_sst



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 79

def read_sst work, pos, len
  # Offset  Size  Contents
  #      0     4  Total number of strings in the workbook (see below)
  #      4     4  Number of following strings (nm)
  #      8  var.  List of nm Unicode strings, 16-bit string length (➜ 3.4)
  total, @sst_size = work.unpack 'V2'
  @sst_offset = [pos, len]
  @workbook.offsets.store :sst, @sst_offset
  _read_sst work, pos, 8
end

#read_string(work, count_length = 1) ⇒ Object

Read a string from the Spreadsheet, such as a Worksheet- or Font-Name, or a Number-Format. See also #read_string_header and #read_string_body



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 92

def read_string work, count_length=1
  #   Offset    Size  Contents
  #        0  1 or 2  Length of the string (character count, ln)
  #   1 or 2       1  Option flags:
  #                   Bit  Mask  Contents
  #                     0  0x01  Character compression (ccompr):
  #                              0 = Compressed (8-bit characters)
  #                              1 = Uncompressed (16-bit characters)
  #                     2  0x04  Asian phonetic settings (phonetic):
  #                              0 = Does not contain Asian phonetic settings
  #                              1 = Contains Asian phonetic settings
  #                     3  0x08  Rich-Text settings (richtext):
  #                              0 = Does not contain Rich-Text settings
  #                              1 = Contains Rich-Text settings
  # [2 or 3]       2  (optional, only if richtext=1)
  #                   Number of Rich-Text formatting runs (rt)
  #   [var.]       4  (optional, only if phonetic=1)
  #                   Size of Asian phonetic settings block (in bytes, sz)
  #     var.      ln  Character array (8-bit characters
  #          or 2∙ln               or 16-bit characters, dependent on ccompr)
  #   [var.]    4∙rt  (optional, only if richtext=1)
  #                   List of rt formatting runs (➜ 3.2)
  #   [var.]      sz  (optional, only if phonetic=1)
  #                   Asian Phonetic Settings Block (➜ 3.4.2)
  chars, offset, wide, phonetic, richtext, available, owing, skip \
    = read_string_header work, count_length
  string, data = read_string_body work, offset, available, wide > 0
  if owing > 0
    @incomplete_string = [string, chars]
  end
  string
end

#read_string_body(work, offset, available, wide) ⇒ Object

Read the body of a string. Returns the String (decompressed if necessary) and the available data (unchanged).



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 127

def read_string_body work, offset, available, wide
  data = work[offset, available]
  string = wide ? data : wide(data)
  [string, data]
end

#read_string_header(work, count_length = 1, offset = 0) ⇒ Object

Read the header of a string. Returns the following information in an Array:

  • The total number of characters in the string

  • The offset of the actual string data (= the length of this header in bytes)

  • Whether or not the string was compressed (0/1)

  • Whether or not the string contains asian phonetic settings (0/1)

  • Whether or not the string contains richtext formatting (0/1)

  • The number of bytes containing characters in this chunk of data

  • The number of characters missing from this chunk of data and expected to follow in a Continue Opcode



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 142

def read_string_header work, count_length=1, offset=0
  fmt = count_length == 1 ? 'C2' : 'vC'
  chars, opts = work[offset, 1 + count_length].unpack fmt
  wide      = opts & 1
  phonetic  = (opts >> 2) & 1
  richtext  = (opts >> 3) & 1
  size      = chars * (wide + 1)
  skip = 0
  if richtext > 0
    runs, = work[offset + 1 + count_length, 2].unpack 'v'
    skip = 4 * runs
  end
  if phonetic > 0
    psize, = work[offset + 1 + count_length + richtext * 2, 4].unpack 'V'
    skip += psize
  end
  flagsize  = 1 + count_length + richtext * 2 + phonetic * 4
  avbl      = [work.size - offset, flagsize + size].min
  have_chrs = (avbl - flagsize) / (1 + wide)
  owing     = chars - have_chrs
  [chars, flagsize, wide, phonetic, richtext, avbl, owing, skip]
end

#wide(string) ⇒ Object

Insert null-characters into a compressed UTF-16 string



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# File 'lib/spreadsheet/excel/reader/biff8.rb', line 166

def wide string
  data = ''
  string.each_byte do |byte| data << byte.chr << 0.chr end
  data
end