Small script to parse the .xml BOM files exported by KiCad. This allows for easy handling and transforming in a (production) pipeline using Ruby

parse_kicad_xml.rb

require 'pry'
require 'json'
require 'nokogiri'
require 'yaml'
require 'hashie'

class GroupedComponents

  @@DEFAULT_FIELDS = %w(refs cnt value footprint)

  def self.csv_header *properties, separator: ','
    line = @@DEFAULT_FIELDS + properties
    separator ? line.join(separator) : line
  end

  attr_reader :refs, :cnt, :value, :footprint, :properties

  def self.from_components components, group_by: [:ref_des, :footprint, :value]
    grouped = components.group_by { |c| group_by.map { |gb| c.send(gb) } }
    grouped.values.map do |group|
      new(group)
    end
  end

  def initialize group
    @refs = group.map(&:ref)

    ref_component = group.first # use the first component in the group tol fill all other fields/properties

    @value = ref_component.value
    @footprint = ref_component.footprint
    @properties = ref_component.properties
  end

  def cnt
    @refs.count
  end

  def csv_line *fields, separator: ','
    line = default_field_values + (properties.fetch_values(*fields) { '' })
    separator ? line.join(separator) : line
  end

  def default_field_values
    @@DEFAULT_FIELDS.map do |fieldname|

      if fieldname == 'refs'
        send(fieldname).join(' ')
      else
        send(fieldname) rescue ''
      end
    end
  end

end

class Component

  @@DEFAULT_FIELDS = %w(ref ref_des ref_num value footprint)

  def self.from_xml xml_component
    new ComponentHelper.component_to_hash(xml_component)
  end

  def self.csv_header *properties, separator: ','
    line = @@DEFAULT_FIELDS + properties
    separator ? line.join(separator) : line
  end

  def method_missing(symbol, *args)
    @properties.send(symbol, *args) || super
  end

  attr_reader :ref, :ref_des, :ref_num, :value, :footprint, :properties

  def initialize h
    @value, @footprint = h.fetch_values :value, :footprint
    @ref, @ref_des, @ref_num = h.fetch(:ref, '').match(/(\D*)(\d*)/).to_a
    @properties = Hashie::Mash.new h.fetch(:properties, {})
  end

  def csv_line *fields, separator: ','
    line = default_field_values + (properties.fetch_values(*fields) { '' })
    separator ? line.join(separator) : line
  end

  def default_field_values
    @@DEFAULT_FIELDS.map { |fieldname| send(fieldname) rescue '' }
  end

end

module ComponentHelper

  extend self

  def get_components doc
    get_xml_components(doc).map { |xc| Component.from_xml xc }
  end

  def get_components_as_hash doc
    components = get_xml_components doc
    components.map { |c| component_to_hash c }
  end

  def get_xml_components doc
    doc.at('components').children.reject { |c| c.is_a? Nokogiri::XML::Text }
  end

  def component_to_hash comp
    reference = comp.attribute('ref').value
    value = comp.xpath('value').text
    footprint = comp.xpath('footprint').text

    { ref: reference, value: value, footprint: footprint, properties: self.component_properties(comp) }
  end

  def component_properties c
    c.xpath('property').map(&:values).to_h.reject { |_k, v| v.empty? }
  end

end

file = ARGV[0]

doc = Nokogiri::XML(File.open(file)) do |config|
  config.options = Nokogiri::XML::ParseOptions::STRICT | Nokogiri::XML::ParseOptions::NOBLANKS
end

components = ComponentHelper.get_components(doc)
property_names = components.inject(Set.new) { |s, c| s.merge c.properties.keys }
comp_hash = ComponentHelper.get_components_as_hash(doc)

binding.pry

def collapsed cpnts
  refs = cpnts.inject([]) { |refs, c| refs << c.ref }
end

# puts comp_hash.to_yaml
# puts JSON.pretty_generate comp_hash

fields = ['Manuf', 'PartNr', 'LCSC Part #', 'Note', 'PartComnt']

# puts Component.csv_header *fields
# puts components.reject { |c| c.properties.Place == "NO" }.map { |c| c.csv_line *fields }

grouped = GroupedComponents.from_components components.reject { |c| c.properties.Place == "NO" }
puts GroupedComponents.csv_header *fields
puts grouped.map { |grouped| grouped.csv_line *fields }