I have a base64 png file bring sent through the params. It is a base64 because it is coming through HTML5 canvas. The attribute it is being passed through as is a nested fields_for. I am not sure but this may be inhibiting it from being saved? doubt it though
I tried the top accepted answer: Rails Carrierwave Base64 image upload
It didn't help
The one different in this Post is that my base64 comes in like such as: "data:image/png;base64,iVvdvadGAqwete...."
my uploader:
class PrintFileUploader < CarrierWave::Uploader::Base
include CarrierWave::MiniMagick
storage :aws
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
end
class CarrierStringIO < StringIO
attr_accessor :original_filename
attr_accessor :content_type
end
version :canvas do
process resize_to_fit: [1500, 1500]
end
def content_type_whitelist
/image\//
end
def extension_whitelist
%w(jpg jpeg png)
end
end
Model:
mount_uploader :print_file, PrintFileUploader
def image_data=(data)
io = CarrierStringIO.new(base64.decode64(data))
# self.mockup_image = io
self.print_file = io
end
Nothing seems to be happening here. When i check the record, the print_file
is nil
I do know base64 carrierwave gem does exist but this is someting I would like to have done without the use of a gem.
How can i take my base64 png, convert it to carrierwave and have it sent to aws through carrierwaave?
Attempts:
def image_data=(data)
data = data[(data.index(',') + 1)..-1]
io = CarrierStringIO.new(base64.decode64(data))
self.print_file = io
end
also tried adding the data = data[(data.index(',') + 1)..-1]
to the content_type, just to try.
Also tried this in my uploader:
before :cache, :convert_base64
class CarrierStringIO < StringIO
def original_filename
# the real name does not matter
"photo.png"
end
def content_type
# this should reflect real content type, but for this example it's ok
"image/png"
end
end
def convert_base64(file)
if file.respond_to?(:original_filename) && file.original_filename.match(/^base64:/)
fname = file.original_filename.gsub(/^base64:/, '')
ctype = file.content_type
decoded = Base64.decode64(file.read)
file.file.tempfile.close!
decoded = CarrierStringIO.new(decoded)
decoded.original_filename = fname
decoded.content_type = ctype
file.__send__ :file=, decoded
end
file
end
Found ^ this from other accepted answers but none of these seem to be working.
Just in case is matters, my base64 png is coming from javascript from a canvas like so:
var url = canvas.toDataURL('image/png')
$("#canvascontent").val(url);
With the <... id="canvascontent" >
being a hidden field in the form.
The image data is encoded in what's called the data-uri scheme . This format is of type:
data:[<media type>][;base64],<data>
Before you base64 decode this data you need to remove the header:
data = "data:image/png;base64,iVvdvadGAqwete...."
# Strip header
data = data[(data.index(',') + 1)..-1]
# Decode
base64.decode64(data)
Or use the Data URI gem:
uri = URI::Data.new(data)
uri.content_type # image/png
uri.data # Base64 decoded data
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