Initials avatar - create an image with letters for using as the user avatar.

initials_avatar.rb

require "mini_magick"

# require "initials_avatar"
# InitialsAvatar.new(initials: "PC").avatar_path
class InitialsAvatar
  BACKGROUND_COLORS = [
    "#C53030", "#9C4221", "#975A16", "#2F855A", "#2C7A7B", "#2B6CB0", "#434190", "#553C9A", "#97266D"
  ]

  def initialize(initials:)
    @initials = initials
    @background_color = BACKGROUND_COLORS.sample

    create
  end

  def avatar_path
    image.path
  end

  private

  def image
    @image ||= Tempfile.new(%W[mini_magick_ .png])
  end

  def create
    MiniMagick::Tool::Convert.new do | new_image |
      new_image.background "#{@background_color}"
      new_image.pointsize '90'
      new_image.font font
      new_image.fill "#FFFFFF"
      new_image.size '180x180'
      new_image.gravity 'center'
      new_image << "label:#{@initials}"

      new_image << "png:#{image.path}"
    end
  end

  def font
    if `identify -list font | grep Helvetica`.empty?
      "DejaVu-Sans"
    else
      "Helvetica"
    end
  end
end

Usage

app/services/user/default_avatar.rb

# frozen_string_literal: true

require "initials_avatar"

class User
  class DefaultAvatar
    class << self
      def attach(user)
        initials_avatar = InitialsAvatar.new(initials: user.name.initials)
        io = File.open(initials_avatar.avatar_path)

        user.avatar.attach(
          io: io, filename: 'avatar.png', content_type: 'image/png'
        )
      end
    end
  end
end

app/models/user.rb

class User < ApplicationRecord
  ...
  before_create :default_avatar
  ...
  has_person_name
  ...
  def default_avatar
    User::DefaultAvatar.attach(self) unless avatar.attached?
  end
end

to test on circle ci add build step:

 - run:
          name: Install image utils and fonts
          command: |
            sudo apt-get update
            sudo apt-get install -y --no-install-recommends imagemagick libmagickcore-6.q16-3-extra gsfonts
   

mac os:
brew install imagemagick