如何在凤凰城渲染透明的gif像素？

Question

Coming from a Rails background I was hoping I could render a transparent pixel gif. To do this on Rails I simply

gif_data = "GIF89a\x01\x00\x01\x00\x80\xFF\x00\xC0\xC0\xC0\x00\x00\x00!\xF9\x04\x01\x00\x00\x00\x00,\x00\x00\x00\x00\x01\x00\x01\x00\x00\x01\x012\x00;"
respond_to do |format|
  format.gif { render text: gif_data, content_type: "image/gif" }
end

Would appreciate some cleaner way to do it than my own.

Answer 1

After some googling and learning string encodings. I converted the Hex code of the actual transparent gif

47 49 46 38 39 61 01 00 01 00 80 00 00 00 00 00 FF FF FF 21 F9 04 01 00 00 00 00 2C 00 00 00 00 01 00 01 00 00 02 01 44 00 3B

using Hexate package into this

<<71, 73, 70, 56, 57, 97, 1, 0, 1, 0, 128, 0, 0, 0, 0, 0, 255, 255, 255, 33, 249, 4, 1, 0, 0, 0, 0, 44, 0, 0, 0, 0, 1, 0, 1, 0, 0, 2, 1, 68, 0, 59>>

so to use this in a Phoenix Controller I can

gif_data = <<71, 73, 70, 56, 57, 97, 1, 0, 1, 0, 128, 0, 0, 0, 0, 0, 255, 255, 255, 33, 249, 4, 1, 0, 0, 0, 0, 44, 0, 0, 0, 0, 1, 0, 1, 0, 0, 2, 1, 68, 0, 59>>
conn = put_resp_content_type(conn, "image/gif")
text conn, gif_data