A ruby implementation of the Line Thermal Printer ESC/POS Command Specifications.

gem install rescpos

See examples

Specify the template path:

Rescpos.configure do |config|
  config.template_path = "path/to/your/escpos/templates"
end

For rails application, the default template path is set to app/escposes. So you should create the templates under app/escposes directory. But if you want to save the templates into another place, you should config the template path in a rails initializer.

Reports manage the objects that will be used in the templates. You should subclass the Rescpos::Report class to define your own reports. For example:

class SimpleTitledReport < Rescpos::Report
  attr_reader :title

  def initialize(title = '')
    @title = title
  end
end

To render the report, you just need to call the render method of the report.

report = SimpleTitledReport.new('A report with a title')
report.render(:template => "<%= title %>")
# A report with a title

You can also create a pre-defined template for the report.

report.render(:file => 'path/to/the/template')

Rescpos will search for the template with the underscore name of the report under the template path if you do not provide any params when rendering the report.

report.render

This will cause rescpos to search for a template named simple_titled.escpos.erb under app/escposes.

Rescpos use erb to define the templates. So any valid erb templates are valid rescpos templates.

Template’s extension name is set to ‘escpos.erb’.

# dish_item.escpos.erb
<%= text(@dish[:dish_category], :font_size => FONT_BIG) %>
<%= text(key_value("餐桌", @bill[:table]), :font_size => FONT_BIG) %> 
<%= text(key_value("人数", @bill[:num_of_people]), :font_size => FONT_BIG) %>
<%= single_splitline %>
<%= text(key_value("菜品", @dish[:name]), :font_size => FONT_BIG) %>
<%= text(key_value("数量", "#{@dish[:quantity]} [根]"), :font_size => FONT_BIG) %>
<%= single_splitline %>
<%= text(key_value("单号", @bill[:id])) %>
<%= text(key_value("操作员", @bill[:waiter])) %>
<%= text(key_value("下单时间", @bill[:created_at])) %>

In order to print the report, you should create a Rescpos::Printer object and then print the report.

printer = Rescpos::Printer.open('192.168.1.250', 9100)
printer.print(report)
printer.close

You can set the options for printing:

printer.print(report, encoding: 'GBK', cut_mode: :partial_cut)

• Encoding option could be any valid encoding.
• cut_mode option has two values: :full_cut and :partial_cut, by default the mode is set to :partial_cut.