rails 3 + prawn pdf + html_safe

Question

I am using prawn gem to generate PDF reports,

@user.description returns as string "<b>sample text</b> &nspb; <p>sample text</p>"

while appending values to the pdf table

pdftable = Prawn::Document.new
pdftable.table([["#{@user.description}"]],
         :column_widths => {0 => 50, 1 => 60, 2 => 280, }, :row_colors => ["ffffff"])

in this case generated pdf has content with html tags, even i tried applying html_safe but it is not escaping tags.

is it possible to use/apply html_safe inside prawn pdftable, in order to escape html tags?

Answer 1

Once again, html_safe is not the method you should be using; it doesn't do what you think it does. All html_safe does is mark the string as safe, thus telling Rails that it does not need to escape it in a view. When using Prawn it would have no effect.

What it sounds like you want to do is not escape HTML, but strip HTML tags from the string. Rails has an HTML sanitizer in ActionView::Helpers::SanitizeHelper, but by default it allows certain tags; you can turn this behavior off using the tags attribute.

class MyClass
  include ActionView::Helpers::SanitizeHelper

  def remove_html(string)
    sanitize(string, :tags => {}) # empty tags hash tells it to allow no tags
  end
end

obj = MyClass.new
obj.remove_html "<b>sample text</b> &nspb; <p>sample text</p>"
 => "sample text &nspb; sample text"

You can include ActionView::Helpers::SanitizeHelper in your controller to get access to the sanitize method.

Note that the   is still in the string; if you want to remove these HTML entities, you'll need to use some other method; the HTMLEntities gem is one such method:

[1] pry(main)> require 'htmlentities'
=> true
[2] pry(main)> coder = HTMLEntities.new
=> #<HTMLEntities:0x007fb1c126a910 @flavor="xhtml1">
[3] pry(main)> string = "sample text &nbsp; sample text"
=> "sample text &nbsp; sample text"
[4] pry(main)> coder.decode string
=> "sample text   sample text"

(note that in your example, the text says &nspb; instead of  ).

Answer 2

If you are looking for a way to use prawn's inline format than you could also do as following:

pdftable = Prawn::Document.new
cell = make_cell(content: "#{@user.description}", inline_format: true)
pdftable.table([[cell]])