Ultra Fast Excel Writer for Ruby

```ruby require ‘fast_excel’

workbook = FastExcel.open(“hello_world.xlsx”, constant_memory: true) workbook.default_format.set( font_size: 0, # user’s default font_family: “Arial” )

worksheet = workbook.add_worksheet(“Example Report”)

bold = workbook.bold_format worksheet.set_column(0, 0, FastExcel::DEF_COL_WIDTH, bold)

price = workbook.number_format(“#,##0.00”) worksheet.set_column(1, 1, 20, price)

date_format = workbook.number_format(“[$-409]m/d/yy h:mm AM/PM;@”) worksheet.set_column(2, 2, 20, date_format)

worksheet.append_row([“message”, “price”, “date”], bold)

for i in 1..1000 worksheet.append_row([“Hello”, (rand * 10_000_000).round(2), Time.now]) end

worksheet.append_row([“Sum”, FastExcel::Formula.new(“SUM(B2:B1001)”)], bold)

workbook.close ```

See more examples

This repository and gem contain sources of libxlsxwriter

Install

ruby # Gemfile gem 'fast_excel' Or gem install fast_excel

Create Document

ruby workbook = FastExcel.open # creates tmp file # ... send_data(workbook.read_string, filename: "table.xlsx") # read tmp file and delete it

Also can use workbook.remove_tmp_folder to delete tmp file manually

Constant memory mode: saves each row to disk, good for really big files but can not change previous lines that already saved ruby workbook = FastExcel.open(constant_memory: true)

Save to file ruby workbook = FastExcel.open("my_dinner.xlsx")

Write Data

FastExcel will automatically detect data type and one of write_number or write_datetime or write_formula or write_string or write_url ```ruby workbook = FastExcel.open worksheet = workbook.add_worksheet

write specific type value value

worksheet.write_number(row = 0, col = 5, 1_234_567, format = nil)

write value with type detection

worksheet.write_value(row = 0, col = 5, 1_234_567, format = nil)

write row of values. format argument can be format object or array of format objects

worksheet.write_row(row = 1, [“strong”, 123_456, Time.now], format = nil)

write row to the bottom

worksheet.append_row([“strong”, 123_456, Time.now], )

shortcut for append_row()

worksheet « [“strong”, 123_456, Time.now] ```

Saving dates: excel store dates as number of days since 1st January 1900, and FastExcel will make it for you.

To make saving of dates slightly faster can use FastExcel.date_num helper: ruby date_format = workbook.number_format("[$-409]m/d/yy hh:mm;@") worksheet.write_number(0, 0, FastExcel.date_num(Time.now, Time.zone.utc_offset), date_format)

Formulas: special type of value in excel ruby worksheet << [1, 2, 3, 4] worksheet << [FastExcel::Formula.new("SUM(A1:D1)")] # A2 will be shown as 10

URL: Link to website or something else ruby url_format = workbook.add_format(underline: :underline_single, font_color: :blue) # format is optional worksheet.append_row([ FastExcel::URL.new("https://github.com/Paxa/fast_excel"), FastExcel::URL.new("postgres://localhost") ], url_format) # or worksheet.write_url(0, 2, "https://github.com/Paxa/fast_excel", url_format)

Data Formatting

ruby format = workbook.add_format( bold: true, italic: true, font_outline: true, font_shadow: true, text_wrap: true, font_strikeout: true, shrink: true, text_justlast: true, font_size: 13, # default is 11, use 0 for user's default font_name: "Arial", # default is Calibri, also accessible via font_family font_color: :orange, # can use RGB hex as "#FF0000" or 0x00FF00 or color name as symbol or string font_script: :font_subscript, rotation: 10, underline: :underline_single, # or :underline_double or :underline_single_accounting or :underline_double_accounting indent: 1, # border styles border: :border_thin, left: :medium, top: :dashed, right: :double, bottom: :hair, bottom_color: :alice_blue, top_color: "#11ABCD", # Align align: {h: :align_center, v: :align_vertical_center}, num_format: "#,##0.00" )

Shortcuts: ruby workbook.bold_format # bold text workbook.number_format("[$-409]m/d/yy h:mm AM/PM;@") # format for date

Set Column Width

ruby worksheet.set_column(start_col, end_col, width = nil, format = nil) # or worksheet.set_column_width(col, width = 60) # or worksheet.set_columns_width(start_col, end_col, width = 60)

Set Row Height

ruby worksheet.set_row(row_num = 0, height = 30, format = nil)

Column Auto Width

Column authwidth only works for string values, because numbers may have custom formatting

Enabling column auto widths will slow down writing string values for about 15-25%

```ruby require ‘fast_excel’

workbook = FastExcel.open(constant_memory: true)

worksheet = workbook.add_worksheet worksheet.auto_width = true

worksheet.append_row([“some text”, “some longer text for example”])

content = workbook.read_string File.open(‘./some_file.xlsx’, ‘wb’) {|f| f.write(content) } ```

API

This gem is FFI binding for libxlsxwriter C library with some syntax sugar. All original functions is avaliable, for example:

ruby Libxlsxwriter.worksheet_activate(worksheet) # => will call void worksheet_activate(lxw_worksheet *worksheet) # or shorter: worksheet.activate

Full libxlsxwriter documentation: http://libxlsxwriter.github.io/

Generated rdoc: rubydoc.info/github/Paxa/fast_excel

Benchmarks

1000 rows: Comparison: FastExcel: 31.7 i/s Axlsx: 8.0 i/s - 3.98x slower write_xlsx: 6.9 i/s - 4.62x slower

20000 rows: Comparison: FastExcel: 1.4 i/s Axlsx: 0.4 i/s - 3.46x slower write_xlsx: 0.1 i/s - 17.04x slower

Max memory usage, generating 100k rows: FastExcel - 20 MB Axlsx - 60 MB write_xlsx - 100 MB