rails prawn draw a line inside table or cell - ruby-on-rails

Question

I have a table made up of many cells, and in one cell i want to draw a horizontal line, and if i try horizontal_line it shows table document unsupported type.
and i'm using prawn ruby gem
Ex
cell_1 = make_cell(:content => "this row content comes directly ", height: 62.5.mm, size: 6)
cell_2 = make_cell(:content => "this row content comes directly ", height: 62.5.mm, size: 6)
cell_3 = make_cell(:content => "this row content comes directly ", height: 62.5.mm, size: 6)
t = make_table([[cell_1],[cell2], [cell3])
t.draw
i tried like using
cell4 = horizontal_rule(some values)
make_table shows error unrecognized table content, when i add cell4 to it.
How do i draw line inside the table or make cell

Answer 1

I was trying to do the same thing months a go but finally I decided to forget using prawn cause it make every thing hard! If you have enough time to use another pdf generator I recommend you to use Wicked_PDF gem (here) and draw your table with simple html and css. Wicked pdf is faster easier and makes you be more creative.

Answer 2

You need to override the Prawn::Table::Cell class. Here's how I did it:
class RedTriangleCell < Prawn::Table::Cell
def natural_content_width
0
end
def natural_content_height
0
end
def draw_content
color = #pdf.fill_color
#pdf.fill_color("e93131")
#pdf.fill_polygon([-5,2], [-1,8], [3,2])
#pdf.fill_color(color)
end
end
You can drop an instance of this as the cell content and it will render whatever you have in draw_content.