Use headers for file content type recognition.

This commit is contained in:
eal 2017-11-11 23:09:33 +02:00
parent fd12e585c9
commit 260b148b92
1 changed files with 28 additions and 3 deletions

View File

@ -9,9 +9,8 @@ def store(%Plug.Upload{} = file) do
File.cp!(file.path, result_file)
# fix content type on some image uploads
matches = Regex.named_captures(~r/\.(?<ext>(jpg|jpeg|png|gif))$/i, file.filename)
content_type = if file.content_type == "application/octet-stream" and matches do
if matches["ext"] == "jpg", do: "image/jpeg", else: "image/#{matches["ext"]}"
content_type = if file.content_type == "application/octet-stream" do
get_content_type(file.path)
else
file.content_type
end
@ -61,4 +60,30 @@ defp upload_path do
defp url_for(file) do
"#{Web.base_url()}/media/#{file}"
end
def get_content_type(file) do
# PNG: 89 50 4E 47 0D 0A 1A 0A
# GIF: 47 49 46 38 37 61
# GIF: 47 49 46 38 39 61
# JPEG: FF D8 FF DB
# JPEG: FF D8 FF E0 ?? ?? 4A 46 49 46 00 01
# JPEG: FF D8 FF E1 ?? ?? 45 78 69 66 00 00
match = File.open(file, [:read], fn(f) ->
case IO.binread(f, 8) do
<<0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a>> ->
"image/png"
<<0x47, 0x49, 0x46, 0x38, _, 0x61, _, _>> ->
"image/gif"
<<0xff, 0xd8, 0xff, _, _, _, _, _>> ->
"image/jpeg"
_ ->
"application/octet-stream"
end
end)
case match do
{:ok, type} -> type
_e -> "application/octet-stream"
end
end
end