Opening File in Ruby returning empty file - ruby-on-rails

Question

I am currently trying to store a pdf in a hash for an api call in ruby. The path to the pdf is stored as:
/Users/myUserName/Desktop/REPOSITORY/path_to_file.pdf
I am using a block to store the file in the hash as so:
File.open(pdf_location, "rb") do |file|
params = {
other irrelevant entries
:document => file
}
pdf_upload_request('post', params, headers)
end
I am receiving a 400 error from the server that my document is empty and when I do puts file.read, it is empty. However, when I visit the filepath, it's clear that the file is not empty. Am I missing something here? Any help would be greatly appreciated. Thank you!
Edit------
I recorded my http request with vcr, here it is:
request:
method: post
uri: request_uri
body:
encoding: US-ASCII
string: ''
headers:
Authorization:
- Bearer 3ZOCPnwfoN7VfdGh7k4lrBuEYs4gN1
Content-Type:
- multipart/form-data; boundary=-----------RubyMultipartPost
Content-Length:
- '246659'
So i don't think the issue is with me sending the file with multipart encoding
Update--------
The filepaths to the pdf are generated from a url, and stored in a the tmp folder of my application. They are generated through this method:
def get_temporary_pdf(chrono_detail, recording, host)
auth_token = User.find(chrono_detail.user_id).authentication_token
# pdf_location = "https://54.84.224.252/recording/5/analysis.pdf/?token=Ybp37kw7HrSt8NyyPnBZ"
pdf_location = host + '/recordings/' + recording.id.to_s + '/analysis.pdf/?format=pdf&download=true&token=' + auth_token
filename = "Will" + '_' + recording.id.to_s + '_' + Date.new.to_s + '.pdf'
Thread.new do
File.open(Rails.root.join("tmp",filename), "wb") do |file|
file.write(open(pdf_location, {ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE}).read)
end
end
Rails.root.join("tmp",filename)
end
They are then called using the api call:
client.upload_document(patient_id, file_path, description)
I can see them physically in my temp folder, and can view them with preview. Everything seems to work. But as a test of uncertainty, I changed file_path to point to a different pdf:
Users/myUsername/Desktop/example.pdf.
Using this file path worked. The pdf was uploaded to the third party system correctly, I can physically see it there. Do you think this means it is an issue with the tmp folder or how i generate the temporary pdf's?

Answer 1

Most likely, the API is expecting a POST with Content-Type: multipart/form-data. Just sending the file handle (which document: file does) won't work, as the file handle is only relevant to your local Ruby process; and even sending the binary string as a parameter won't work, since your content-type isn't properly set to encode a file.
Since you're already using HTTParty, though, you can fix this by using HTTMultiParty:
require 'httmultiparty'
class SomeClient
include HTTMultiParty
base_uri 'http://localhost:3000'
end
SomeClient.post('/', :query => {
:foo => 'bar',
:somefile => File.new('README.md')
})

Answer 2

Try this:
file = File.read(pdf_location)
params = {
# other irrelevant entries
document: file
}
headers = {}
pdf_upload_request('post', params, headers)
Not sure but may be you need to close file first...

Answer 3

So the issue arose from the multi threading i used to avoid timeout errors. The file path would get generated and referenced in the api call before anything was actually written into the document.