Module Spreadsheet::Excel::Writer::Biff8
In: lib/spreadsheet/excel/writer/biff8.rb
Column Format Row Font Enumerable Worksheet\n[lib/spreadsheet/excel.rb\nlib/spreadsheet/worksheet.rb] Link Workbook Workbook\n[lib/spreadsheet/excel.rb\nlib/spreadsheet/excel/workbook.rb] SstEntry String Row Array Worksheet ExcelCompatibleWorkbook Format Worksheet Workbook DelegateClassSpreadsheet::Format Writer Compatibility Formula Reader\n[lib/parseexcel/parseexcel.rb\nlib/spreadsheet/excel/reader.rb\nlib/spreadsheet/excel/reader/biff5.rb\nlib/spreadsheet/excel/reader/biff8.rb] Error lib/spreadsheet/excel.rb lib/spreadsheet/link.rb lib/spreadsheet/formula.rb lib/spreadsheet/workbook.rb lib/spreadsheet/font.rb lib/spreadsheet/column.rb lib/spreadsheet/format.rb lib/spreadsheet/writer.rb lib/spreadsheet/row.rb Encodings lib/spreadsheet/excel.rb lib/spreadsheet/excel/row.rb lib/spreadsheet/excel/reader/biff5.rb lib/spreadsheet/excel/worksheet.rb lib/spreadsheet/excel/sst_entry.rb lib/spreadsheet/excel/error.rb lib/spreadsheet/excel/workbook.rb lib/spreadsheet/excel/writer/format.rb lib/spreadsheet/excel/writer/workbook.rb lib/spreadsheet/excel/writer/worksheet.rb Biff8 Writer Biff5 Biff8 Internals Offset Excel Datatypes ParseExcel Compatibility Spreadsheet dot/m_34_0.png

This Module collects writer methods such as unicode_string that are specific to Biff8. This Module is likely to be expanded as Support for older Versions of Excel grows and methods get moved here for disambiguation.

Methods

_unicode_string   compress_unicode_string   unicode_string  

Included Modules

Spreadsheet::Encodings

Public Instance methods

_unicode_string(string, count_length=1)

Encode string into a Biff8 Unicode String Header and Body.

[Source]

    # File lib/spreadsheet/excel/writer/biff8.rb, line 42
42:   def _unicode_string string, count_length=1
43:     data = internal string
44:     size = data.send(@@bytesize) / 2
45:     fmt = count_length == 1 ? 'C2' : 'vC'
46:     data, wide = compress_unicode_string data
47:     opts = wide
48:     header = [
49:       size, # Length of the string (character count, ln)
50:       opts, # Option flags:
51:             # Bit  Mask  Contents
52:             #   0  0x01  Character compression (ccompr):
53:             #            0 = Compressed (8-bit characters)
54:             #            1 = Uncompressed (16-bit characters)
55:             #   2  0x04  Asian phonetic settings (phonetic):
56:             #            0 = Does not contain Asian phonetic settings
57:             #            1 = Contains Asian phonetic settings
58:             #   3  0x08  Rich-Text settings (richtext):
59:             #            0 = Does not contain Rich-Text settings
60:             #            1 = Contains Rich-Text settings
61:       #0x00,# (optional, only if richtext=1) Number of Rich-Text
62:             #                                formatting runs (rt)
63:       #0x00,# (optional, only if phonetic=1) Size of Asian phonetic
64:             #                                settings block (in bytes, sz)
65:     ].pack fmt
66:     data << '' # (optional, only if richtext=1)
67:                # List of rt formatting runs (➜ 3.2)
68:     data << '' # (optional, only if phonetic=1)
69:                # Asian Phonetic Settings Block (➜ 3.4.2)
70:     [header, data, wide]
71:   end
compress_unicode_string(data)

Check whether the string data can be compressed (i.e. every second byte is a Null-byte) and perform compression. Returns the data and compression_status (0/1)

[Source]

    # File lib/spreadsheet/excel/writer/biff8.rb, line 16
16:   def compress_unicode_string data
17:     compressed = ''
18:     expect_null = false
19:     data.each_byte do |byte|
20:       if expect_null
21:         if byte != 0
22:           return [data, 1] # 1 => Data consists of wide Chars
23:         end
24:         expect_null = false
25:       else
26:         compressed << byte
27:         expect_null = true
28:       end
29:     end
30:     [compressed, 0] # 0 => Data consists of compressed Chars
31:   end
unicode_string(string, count_length=1)

Encode string into a Biff8 Unicode String. Header and body are encoded separately by _unicode_string. This method simply combines the two.

[Source]

    # File lib/spreadsheet/excel/writer/biff8.rb, line 35
35:   def unicode_string string, count_length=1
36:     header, data, _ = _unicode_string string, count_length
37:     header << data
38:   end

[Validate]