I get image files sent from an Android app to my Rails API. I decode the images using this:
StringIO.new(Base64.decode64(image[1]))
The issue is that it takes too much time; on heroku it takes even longer.
Is there another way to do this that's faster and more efficient?
You can also use this for decode base64:
# this method for decode base64 code to file
def parse_image_data(image[1])
base64_file = image[1]
ext, string = base64_file.split(',')
ext = MIME::Types[base64_file].first.preferred_extension if ext.include?("base64")
tempfile = Tempfile.new(["#{DateTime.now.to_i}", ".#{ext}"])
tempfile.binmode
tempfile.write Base64.decode64(string)
tempfile.rewind
tempfile
end
Related
I've been trying to manipulate a file that's base64 encoded that I'm recieving from my client.
I'm currently using https://github.com/zdavatz/spreadsheet/blob/master/GUIDE.md to manipulate it, however, there doesn't appear to be any way to open a file directly from the base64 blob, or should I write it and then read from it? can't that a potential security threat for the server?
for example, if I recieve a file :
file = params[:file] with contents:
data:application/vnd.ms-excel;base64,0M8R4KGxGuEAAAAAAAAAAAAAAAAAAAAAOwADAP7
(should I remove the data:application/vnd.ms-excel;base64, ?)
I'd like to open it with this:
Spreadsheet.client_encoding = 'UTF-8'
book = Spreadsheet.open "#{Rails.root}/app/assets/spreadsheet/event.xls"
(or with a blob or temp fle)
Sorry if it's pretty obvious, been looking for hours and there's not much info about it available, tried creating a temp file first but I don't think that's supported and there's not much I can get from the docs.
Shot in the dark: Maybe decode it, write to binary-enabled tempfile, and then feed that to Spreadsheet?
tmpfile = Tempfile.new.binmode
tmpfile << Base64.decode64(params[:file])
tmpfile.rewind
book = Spreadsheet.open(tmpfile)
I have working Paperclip gem in my app for documents (pdf, doc). I need to pass the document to some other third party application via post request.
I tried to convert the paperclip attachment via Base64 but it throws error:
no implicit conversion of Tempfile into String
Here is how I did it:
# get url from the paperclip file
url = document.doc.url # https://s3-ap-southeast-1.amazonaws.com/xx-eng/documents/xx/000/000/xx/original/doc.pdf
file_data = open(url)
# Encode the bytes to base64 - this line throw error
base_64_file = Base64.encode64(file_data)
Do you have any suggestion how to avoid the Tempfile error?
You need to read file first.
base_64_file = Base64.encode64(file_data.read)
Here is working example:
$ bundle exec rails c
=> file = open("tmp/file.pdf")
#> #<File:tmp/receipts.pdf>
=> base_64 = Base64.encode64(file)
#> TypeError: no implicit conversion of File into String
=> base_64 = Base64.encode64(file.read)
#> "JVBERi0xLjQKMSAwIG9iago8PAovVGl0b/BBQEPgQ ......J0ZgozMDM0OQolJUVPRgo=\n"
The answer from #3елёный didn't work to me - maybe because it's the S3 file.
However I managed to find a way with Paperclip method:
file_data = Paperclip.io_adapters.for(url).read
base_64_file = Base64.encode64(file_data)
I'm having trouble calling image.write with MiniMagick on a decoded base64 image in Rails. Every line seems to be working properly except for image.write. The code below is in my Rails API ImageController, which my React frontend is hitting through a POST request with the encoded image.
def create
uploaded_io = params["image_io"]["base64"] # base64 string + metadata
metadata = uploaded_io.split(',/')[0] + "," # "data:image/jpeg;base64,"
filetype = metadata.split("/")[1].split("base64")[0][0...-1] # "jpeg"
base64_string = uploaded_io[metadata.size..-1] # base64 string w/o metadata
blob = Base64.decode64(base64_string)
image = MiniMagick::Image.read(blob)
image.write `#{Time.new.to_i}.#{filetype}`
storage = Google::Cloud::Storage.new(
project_id: ENV['GOOGLE_CLOUD_PROJECT'],
credentials: JSON.parse(File.read('config/google_cloud_credentials.json'))
)
bucket = storage.bucket "auto-stock-189103.appspot.com"
bucket.create_file image,`test/#{Time.new.to_i}.jpg`
end
I added comments to the first few lines in the code describing their value. base64_string was too long to comment, so here is its value:
"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"
Testing it here renders the correct image (a red square), but when I run the image.write line it returns the following error:
bin/rails: No such file or directory - 1513397345.jpeg
*** NoMethodError Exception: undefined method `write' for nil:NilClass
nil
Here's the return value of image = MiniMagick::Image.read(blob) for reference:
#<MiniMagick::Image:0x00007f9ba76ba1f8 #path="/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu", #tempfile=#<Tempfile:/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu (closed)>, #info=#<MiniMagick::Image::Info:0x00007f9ba76ba1d0 #path="/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu", #info={}>>
Ultimately, my goal is to upload the image to Google Cloud so please let me know if there's a better way to go about this. I'm following this answer from a similar question, which is why I have it structured this way.
I think your problem is that you're using backticks where you mean to use double quotes:
image.write `#{Time.new.to_i}.#{filetype}`
# ----------^----------------------------^
Backticks will attempt to execute their contents in the shell. You don't have an executable file named 1513397345.jpeg (which is what #{Time.new.to_i}.#{filetype} evaluates to) so you get an error.
You just want to use plain old double quotes to get the string interpolation you're expecting:
image.write "#{Time.new.to_i}.#{filetype}"
and again a few lines below that:
bucket.create_file image, "test/#{Time.new.to_i}.jpg"
Furthermore, you probably want to store that filename in a variable because Time.new.to_i isn't guaranteed to be the same in both invocation:
name = "#{Time.new.to_i}.#{filetype}
image.write name
#...
bucket.create_file image, name
I have a Dragonfly processor which should take a given PDF and return a PNG of the first page of the document.
When I run this processor via the console, I get back the PNG as expected, however, when in the context of Rails, I'm getting it as a PDF.
My code is roughly similar to this:
def to_pdf_thumbnail(temp_object)
tempfile = new_tempfile('png')
args = "'#{temp_object.path}[0]' '#{tempfile.path}'"
full_command = "convert #{args}"
result = `#{full_command}`
tempfile
end
def new_tempfile(ext=nil)
tempfile = ext ? Tempfile.new(['dragonfly', ".#{ext}"]) : Tempfile.new('dragonfly')
tempfile.binmode
tempfile.close
tempfile
end
Now, tempfile is definitely creating a .png file, but the convert is generating a PDF (when run from within Rails 3).
Any ideas as to what the issue might be here? Is something getting confused about the content type?
I should add that both this and a standard conversion (asset.png.url) both yield a PDF with the PDF content as a small block in the middle of the (A4) image.
An approach I’m using for this is to generate the thumbnail PNG on the fly via the thumb method from Dragonfly’s ImageMagick plugin:
<%= image_tag rails_model.file.thumb('100x100#', format: 'png', frame: 0).url %>
So long as Ghostscript is installed, ImageMagick/Dragonfly will honour the format / frame (i.e. page of the PDF) settings. If file is an image rather than a PDF, it will be converted to a PNG, and the frame number ignored (unless it’s a GIF).
Try this
def to_pdf_thumbnail(temp_object)
ret = ''
tempfile = new_tempfile('png')
system("convert",tmp_object.path[0],tmpfile.path)
tempfile.open {|f| ret = f.read }
ret
end
The problem is you are likely handing convert ONE argument not two
Doesn't convert rely on the extension to determine the type? Are you sure the tempfiles have the proper extensions?
I just started using resque to do some processing on some very large files in the background, and I'm having trouble figuring out how to pass a file to a resque worker. I use rails to handle the file upload, and rails creates an ActionDispatch::Http::UploadedFile object for each file uploaded from the form.
How do send this file to a resque worker? I tried sending a custom hash of just the pathname of the temporary file and original filename, but I can't reopen the temporary file in the resque worker anymore (just a normal Errno::ENOENT - No such file or directory) because rails seems to delete that temporary file after the request ends.
Http::UploadedFileisn't accessible once the request finishes. You need to write the file somewhere (or use s3 as temp storage). Pass resque the path to the file that you wrote.
I just spent two days trying to do this and finally figured it out. You need to Base64 encode the file so that it can be serialized into json. Then you need to decode it in the worker and create a new
ActionDispatch::Http::UploadedFile
Here's how to encode and pass to resque:
// You only need to encode the actual file, everything else in the
// ActionDispatch::Http::UploadedFile object is just string or a hash of strings
file = params[:file] // Your ActionDispatch::Http::UploadedFile object
file.tempfile.binmode
file.tempfile = Base64.encode64(file.tempfile.read)
Resque.enqueue(QueueWorker, params)
And Here's how to decode and convert back to an object within your worker
class QueueWorker
#queue = :main_queue
def self.perform(params)
file = params['file']
tempfile = Tempfile.new('file')
tempfile.binmode
tempfile.write(Base64.decode64(file['tempfile']))
// Now that the file is decoded you need to build a new
// ActionDispatch::Http::UploadedFile with the decoded tempfile and the other
// attritubes you passed in.
file = ActionDispatch::Http::UploadedFile.new(tempfile: tempfile, filename: file['original_filename'], type: file['content_type'], head: file['headers'])
// This object is now the same as the one in your controller in params[:file]
end
end