I am trying to create a new file and then write some content to it just to create a basic backup of a template.
When I log out the values of filename and file_content they are correct, but when I send the data all I get is a file named after the method (download_include) and a fixnum inside the file, the last one made was 15.
# POST /download_include/:id
def download_include
#include = Include.find(params[:id])
version_to_download = #include.latest_version_record
filename = "#{version_to_download.name}"
file_content = "#{version_to_download.liquid_code.to_s}"
file = File.open(filename, "w") { |f| f.write (file_content) }
send_data file
end
I also tried send_file but that produces the error
no implicit conversion of Fixnum into String
I also tried to just write dummy values like below, and it still produced a file named after the method with a fixnum inside it.
file = File.open("DOES THIS CHANGE THE FILENAME?", "w") { |f| f.write ("FILE CONTENT?") }
I feel I am missing something obvious but I cannot figure it out after looking at many examples here and in blogs.
If you don't end along the filename as an option for send_data, it defaults to the method name.
Secondly, the download wants to read the data from a buffer. My guess is your syntax is just sending a file handle.
Try this...
send_data(file.read, filename: filename)
Or skip the intermediate file and try...
send_data(version_to_download.liquid_code.to_s, filename: filename)
Related
When trying to write a string / unzipped file to a Tempfile by doing:
temp_file = Tempfile.new([name, extension])
temp_file.write(unzipped_io.read)
Which throws the following error when I do this with an image:
Encoding::UndefinedConversionError - "\xFF" from ASCII-8BIT to UTF-8
When researching it I found out that this is caused because Ruby tries to write files with an encoding by default (UTF-8). But the file should be written as binary, so it ignores any file specific behavior.
Writing regular File you would be able to do this as following:
File.open('/tmp/test.jpg', 'rb') do |file|
file.write(unzipped_io.read)
end
How to do this in Tempfile
Tempfile.new passes options to File.open which accepts the options from IO.new, in particular:
:binmode
If the value is truth value, same as “b” in argument mode.
So to open a tempfile in binary mode, you'd use:
temp_file = Tempfile.new([name, extension], binmode: true)
temp_file.binmode? #=> true
temp_file.external_encoding #=> #<Encoding:ASCII-8BIT>
In addition, you might want to use Tempfile.create which takes a block and automatically closes and removes the file afterwards:
Tempfile.create([name, extension], binmode: true) do |temp_file|
temp_file.write(unzipped_io.read)
# ...
end
I have encountered the solution in an old Ruby forum post, so I thought I would share it here, making it easier for people to find:
https://www.ruby-forum.com/t/ruby-binary-temp-file/116791
Apparently Tempfile has an undocumented method binmode, which changes the writing mode to binary and thus ignoring any encoding issues:
temp_file = Tempfile.new([name, extension])
temp_file.binmode
temp_file.write(unzipped_io.read)
Thanks unknown person who mentioned it on ruby-forums.com in 2007!
Another alternative is IO.binwrite(path, file_content)
I am using Libreconv gem to convert word to doc but it's not working with S3
bucket = Aws::S3::Bucket.new('bucket-name')
object = bucket.object file.attachment.blob.key
path = object.presigned_url(:get)
Libreconv.convert(path, "public/test.pdf")
If I try to convert this path to PDF using Libreconv then it's give me filename too long error. I have wrriten this code under ActiveJobs. So kindly provide me solutions as per ActiveJobs.
Can someone please suggest me how can I convert word file to pdf.
Here path is https://domain.s3.amazonaws.com/Bf5qPUP3znZGCHCcTWHcR5Nn?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIZ6RZ7J425ORVUYQ%2F20181206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181206T051240Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=b89c47a324b2aa423bf64dfb343e3b3c90dce9b54fa9fe1bc4efa9c248e912f9
and error I am getting is
Error: source file could not be loaded
*** Errno::ENAMETOOLONG Exception: File name too long # rb_sysopen - /tmp/Bf5qPUP3znZGCHCcTWHcR5Nn?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIZ6RZ7J425ORVUYQ%2F20181206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181206T051240Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=b89c47a324b2aa423bf64dfb343e3b3c90dce9b54fa9fe1bc4efa9c248e912f9.pd
It seems that you PDF is created with all the params needed to fetch docx from S3.
I suppose it happens in this line:
target_tmp_file = "#{target_path}/#{File.basename(#source, ".*")}.#{File.basename(#convert_to, ":*")}"
#source is https://domain.s3.amazonaws.com/Bf5qPUP3znZGCHCcTWHcR5Nn?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIZ6RZ7J425ORVUYQ%2F20181206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181206T051240Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=b89c47a324b2aa423bf64dfb343e3b3c90dce9b54fa9fe1bc4efa9c248e912f9 and
> File.basename(#source, ".*")
=> "Bf5qPUP3znZGCHCcTWHcR5Nn?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIZ6RZ7J425ORVUYQ%2F20181206%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20181206T051240Z&X-Amz-Expires=900&X-Amz-SignedHeaders=host&X-Amz-Signature=b89c47a324b2aa423bf64dfb343e3b3c90dce9b54fa9fe1bc4efa9c248e912f9"
As a result Libreconv gem tries to create a tmp file with this long name and it's too long - that's why an error is raised.
Possible solution: split the process into separate steps of fetching file and converting it. Something like:
require "open-uri"
bucket = Aws::S3::Bucket.new('bucket-name')
object = bucket.object file.attachment.blob.key
path = object.presigned_url(:get)
doc_file = open(path)
begin
Libreconv.convert(doc_file.path, "public/test.pdf")
ensure
doc_file.delete
end
following is the answer using combine pdf gem
tape = Tape.new(file)
result = tape.preview
tempfile = Tempfile.new(['foo', '.pdf'])
File.open(tempfile, 'wb') do |f|
f.write result
end
path = tempfile.path
combine_pdf(path)
and for load file for S3 I have used
object = #bucket.object object_key
path = object.presigned_url(:get)
response = Net::HTTP.get_response(URI.parse(path)).body
I need to serve some data from my database in a zip file, streaming it on the fly such that:
I do not write a temporary file to disk
I do not compose the whole file in RAM
I know that I can do streaming generation of zip files to the filesystemk using ZipOutputStream as here. I also know that I can do streaming output from a rails controller by setting response_body to a Proc as here. What I need (I think) is a way of plugging those two things together. Can I make rails serve a response from a ZipOutputStream? Can I get ZipOutputStream give me incremental chunks of data that I can feed into my response_body Proc? Or is there another way?
Short Version
https://github.com/fringd/zipline
Long Version
so jo5h's answer didn't work for me in rails 3.1.1
i found a youtube video that helped, though.
http://www.youtube.com/watch?v=K0XvnspdPsc
the crux of it is creating an object that responds to each... this is what i did:
class ZipGenerator
def initialize(model)
#model = model
end
def each( &block )
output = Object.new
output.define_singleton_method :tell, Proc.new { 0 }
output.define_singleton_method :pos=, Proc.new { |x| 0 }
output.define_singleton_method :<<, Proc.new { |x| block.call(x) }
output.define_singleton_method :close, Proc.new { nil }
Zip::IoZip.open(output) do |zip|
#model.attachments.all.each do |attachment|
zip.put_next_entry "#{attachment.name}.pdf"
file = attachment.file.file.send :file
file = File.open(file) if file.is_a? String
while buffer = file.read(2048)
zip << buffer
end
end
end
sleep 10
end
end
def getzip
self.response_body = ZipGenerator.new(#model)
#this is a hack to preven middleware from buffering
headers['Last-Modified'] = Time.now.to_s
end
EDIT:
the above solution didn't ACTUALLY work... the problem is that rubyzip needs to jump around the file to rewrite the headers for entries as it goes. particularly it needs to write the compressed size BEFORE it writes the data. this is just not possible in a truly streaming situation... so ultimately this task may be impossible. there is a chance that it might be possible to buffer a whole file at a time, but this seemed less worth it. ultimately i just wrote to a tmp file... on heroku i can write to Rails.root/tmp less instant feedback, and not ideal, but neccessary.
ANOTHER EDIT:
i got another idea recently... we COULD know the compressed size of the files if we do not compress them. the plan goes something like this:
subclass the ZipStreamOutput class as follows:
always use the "stored" compression method, in other words do not compress
ensure we never seek backwards to change file headers, get it all right up front
rewrite any code related to TOC that seeks
I haven't tried to implement this yet, but will report back if there's any success.
OK ONE LAST EDIT:
In the zip standard: http://en.wikipedia.org/wiki/Zip_(file_format)#File_headers
they mention that there's a bit you can flip to put the size, compressed size and crc AFTER a file. so my new plan was to subclass zipoutput stream so that it
sets this flag
writes sizes and CRCs after the data
never rewinds output
furthermore i needed to get all the hacks in order to stream output in rails fixed up...
anyways it all worked!
here's a gem!
https://github.com/fringd/zipline
I had a similar issue. I didn't need to stream directly, but only had your first case of not wanting to write a temp file. You can easily modify ZipOutputStream to accept an IO object instead of just a filename.
module Zip
class IOOutputStream < ZipOutputStream
def initialize io
super '-'
#outputStream = io
end
def stream
#outputStream
end
end
end
From there, it should just be a matter of using the new Zip::IOOutputStream in your Proc. In your controller, you'd probably do something like:
self.response_body = proc do |response, output|
Zip::IOOutputStream.open(output) do |zip|
my_files.each do |file|
zip.put_next_entry file
zip << IO.read file
end
end
end
It is now possible to do this directly:
class SomeController < ApplicationController
def some_action
compressed_filestream = Zip::ZipOutputStream.write_buffer do |zos|
zos.put_next_entry "some/filename.ext"
zos.print data
end
compressed_filestream .rewind
respond_to do |format|
format.zip do
send_data compressed_filestream .read, filename: "some.zip"
end
end
# or some other return of send_data
end
end
This is the link you want:
http://info.michael-simons.eu/2008/01/21/using-rubyzip-to-create-zip-files-on-the-fly/
It builds and generates the zipfile using ZipOutputStream and then uses send_file to send it directly out from the controller.
Use chunked HTTP transfer encoding for output: HTTP header "Transfer-Encoding: chunked" and restructure the output according to the chunked encoding specification, so no need to know the resulting ZIP file size at the begginning of the transfer. Can be easily coded in Ruby with the help of Open3.popen3 and threads.
I have a problem with "latex-rails" gem. I`m trying to make function which will generate a pdf. This is my code:
code = "\\documentclass[12pt]{article}
\\begin{document}
Don't forget to include examples of topicalization.
\\end{document}"
#latex_config={:command => 'xelatex',:parse_twice => true}
LatexToPdf.generate_pdf(code, #latex_config, parse_twice = true)
In a log file I can see that "Output written on input.pdf (1 page).", but there is no input.pdf and I have no clue what is wrong.
For the sake of having an answer posted here instead of in the comments...
The LatexToPdf.generate_pdf method returns the pdf binary itself, which you'll need to write to a file. Here's one way to accomplish this:
code = "\\documentclass[12pt]{article} \\begin{document} Test \\end{document}"
latex_config = {command: 'xelatex', parse_runs: 2}
result = LatexToPdf.generate_pdf(code, latex_config)
f = File.new("testfile.pdf", "w")
f.write(result)
f.close
As you noted, the log file states that the output was written to a file; however, rails-latex writes this file to a temporary directory and destroys the directory at the end of the method (hence the need to write the returned binary content to a file yourself).
I need to create a local xml file from a rails application and then copy it to a location on another server.
I have tried using the File.new option to create a new file but it gives me an error saying the file does not exist. After looking closer at the documentation it says that File.new opens a file that already exists.
I can't see any way to create a local file using Ruby, what am I missing?
Assuming you have built up your XML into a string, xml_string, you can do:
xml_file = open(filename, 'w')
xml_file.write xml_string
xml_file.close
Or using the block syntax to achieve this in one line:
File.open(local_filename, 'w') { |f| f.write(xml_string) }