Our store software contains an extensive set of routines for processing uploaded images and resizing them into various image sizes. We’ve recently been adding some code to support a bulk import function and it’s become necessary to somehow fake uploading a file, given a specific URL for an image.<\/p>\n\n\n\n
The basic plan is to use Net::HTTP to connect to the remote server and grab the image and save it in a temporary file. It turns out that Rails contains a UploadedTempfile class which is a subclass of Tempfile, and this is used by the CGI routines to handle any uploaded files.<\/p>\n\n\n\n\n\n\n\n
So all we need to do is create our own instance of UploadedTempfile, set some attributes and then pass it along to our existing routines as if it were a real uploaded file.<\/p>\n\n\n\n
uri = URI.parse(image_url)\nimage_file_name = File.basename(uri.path) # Extract the file name\nimage_file = nil\nbegin\n timeout(10) do\n Net::HTTP.start(uri.host, uri.port) do |http|\n resp = http.get(uri.path)\n image_file = ActionController::UploadedTempfile.new(image_file_name)\n image_file.binmode\n image_file.write(resp.body)\n image_file.original_path = image_file_name\n image_file.rewind\n end\n end\nrescue TimeoutError\n raise \"Timeout connecting to #{uri.host}\"\nend\n<\/code><\/pre>\n\n\n\nThere are a few things that need to be set up, so that the fake upload file works properly.<\/p>\n\n\n\n
The file is set to binary mode with<\/p>\n\n\n\n
image_file.binmode<\/p><\/blockquote>\n\n\n\n
The original file name is set with<\/p>\n\n\n\n
image_file.original_path = image_file_name<\/p><\/blockquote>\n\n\n\n
A content type attribute can also be set with<\/p>\n\n\n\n
image_file.content_type<\/p><\/blockquote>\n\n\n\n
but we don’t use this attribute, so it’s not set here.<\/p>\n\n\n\n
Finally we rewind the file so that we can read it later on in the image processing routines. When we’re finished with the temporary file, we can delete it with a<\/p>\n\n\n\n
image_file.close!<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"
Our store software contains an extensive set of routines for processing uploaded images and resizing them into various image sizes. We’ve recently been adding some code to support a bulk import function and it’s become necessary to somehow fake uploading … Continue reading