Hide file which is showing despite of gitignore

git update-index --assume-unchanged FILEPATH
 

Paste image into prawn pdf with StringIO and base-64 encoding

I getting BASE64_IMAGE_GOES_HERE from signature_pad js lib with getSignatureImage() method.

  def render
    pdf = Prawn::Document
    pdf.image StringIO.new(Base64.decode64(splitBase64(BASE64_IMAGE_GOES_HERE)[:data])), at: [10, cursor - 50], width: 200, height: 125
  end

  def splitBase64(uri)
    if uri.match(%r{^data:(.*?);(.*?),(.*)$})
      return {
        type:      $1, # "image/png"
        encoder:   $2, # "base64"
        data:      $3, # data string
        extension: $1.split('/')[1] # "png"
        }
    end
  end
 

Multi-column PDF generating with Prawn in ruby

For example, you need to generate a content (or table) with width 20-30% of page and it should not break the page if height is too big but should continue on the same page in the right side.

It will look like that:

Prawn has very useful methodfor doing that called ‘column_box’.

# Example of 2 columns table with some styling
def render_left_products_list
    column_box([-5, cursor], columns: 2, height: cursor, position: :left, width: bounds.width, spacer: 40) do

      @categories.each do |category|
        move_down 6
        table line_item_rows(category), position: :left, cell_style: { size: 7, text_color: "000000", borders: [:bottom], border_lines: [:dotted], padding: [2, 0, 4, 0] } do
          column(1).style align: :right
          style(row(0), text_color: HEADER_COLOR)
          align                = { 0 => :left, 1 => :right}
          self.width           = 285
          self.header          = true
          column(1).font_style = :bold
          row(0).size          = 8
          row(0).font_style    = :bold
          row(0).borders       = []
        end
      end
    end
  end

  def line_item_rows(category)
    [[category.name, '']] +
    category.products.map do |product|
      [product.name, "#{format('%.2f', product.price)} USD"]
    end
  end
 

Ruby on Rails convert array into Relation object

scope :with_scope, -> { where(id: ARRAY_COLLECTION.map(&:id)) }
 

Language plural rules (includes I18n)

Table with plural rules: Читать дальше »

 

Rails 4.1 html and tags chars sanitize

To remove all tags and chars like ‘nbsp;’ in rails 4.1 do that:
= sanitize(post.description).truncate(350, :separator => " ").html_safe
 

Rails timezones difference

  • In Rails, Time.zone refers to the Rails (not system) timezone, set by config.time_zone (typically in application.rb)
  • DateTime and Time are not otherwise Rails aware, therefore, DateTime.now and Time.now both return times in the system timezone.
  • 1.month.ago and similar methods use the Rails timezone, but DateTime.now.last_month uses the system timezone
  • When retrieving things from ActiveRecord, they will be timezoned to the Rails timezone, so Product.first.created_at will give you a time in the Rails timezone (not the system timezone)

So, don’t mix Rails timezone methods like “1.month.ago” with system timezone methods like “DateTime.now.last_month”