lib/table_transform/excel_creator.rb
require 'write_xlsx'
require_relative 'table'
module TableTransform
# Creates excel file
class ExcelCreator
def initialize(filename)
@workbook = WriteXLSX.new(filename)
@formats = {}
end
def create!
@workbook.close
end
def add_tab(name, table)
set_formats(table.column_properties) if table.is_a?(TableTransform::Table)
create_table(name, table)
end
#################################
private
def self.default_properties(table_name)
TableTransform::Table::TableProperties.new(
{
name: table_name.tr(' ', '_'),
auto_filter: true
}
)
end
# estimated column width of format
def self.format_column_size(format)
return 0 if format.nil?
f = format.gsub(/\[.*?\]/, '').split(';')
f.map{|x| x.size}.max
end
# @return array with column width per column
def self.column_width(table, auto_filter_correct = true, max_width = 100)
return [] unless table.is_a? TableTransform::Table
data = table.to_a
auto_filter_size_correction = auto_filter_correct ? 3 : 0
res = Array.new(data.first.map { |name|
[name.to_s.size + auto_filter_size_correction, format_column_size(table.column_properties[name][:format])].max
})
data.each { |row|
row.each_with_index { |cell, column_no|
res[column_no] = [cell.to_s.size, res[column_no]].max
}
}
res.map! { |x| [x, max_width].min }
end
def set_formats(column_properties)
# find all :formats across all columns
column_properties.each{|_,v|
f = v[:format]
@formats[f] ||= @workbook.add_format(:num_format => f) unless f.nil?
}
end
def create_column_metadata(column_properties, formats, formulas)
res = []
column_properties.each{ |header_name, data|
col_props = TableTransform::Properties.new data.to_h
#format (replace str format with excel representation)
col_props.update({format: formats[col_props[:format]]}) unless col_props[:format].nil?
#formula
formula = formulas[header_name]
col_props.update({formula: formula}) unless formula.nil?
#header
col_props.update({header: header_name})
res << col_props.to_h
}
res
end
def create_table(name, table)
worksheet = @workbook.add_worksheet(name)
data = table.to_a
return if data.nil? or data.empty? # Create empty worksheet if no data
table_properties = ExcelCreator::default_properties(name).update(table.table_properties.to_h)
col_width = ExcelCreator::column_width(table, table_properties[:auto_filter])
header = data.shift
data << [nil] * header.count if data.empty? # Add extra row if empty
worksheet.add_table(
0, 0, data.count, header.count - 1,
{
:name => table_properties[:name],
:data => data,
:autofilter => table_properties[:auto_filter] ? 1 : 0,
:columns => create_column_metadata(table.column_properties, @formats, table.formulas)
}
)
# Set column width
col_width.each_with_index { |size, column| worksheet.set_column(column, column, size) }
end
end
end