Rails 5中如何获取Wicked PDF生成的临时文件路径？

Hey there! Great question about WickedPdf's temporary file handling—let me break this down for you clearly.

First, a key clarification: When you use the pdf_from_string method like this:

pdf = WickedPdf.new.pdf_from_string('<h1>Hello There!</h1>')

WickedPdf doesn’t create a persistent temporary file by default. The method returns the PDF content directly as binary data, so there’s no disk-based temp file path to retrieve right out of the box.

That said, if you do need to generate a temporary file and access its path, here are two straightforward approaches:

1. Manually Create and Write to a Temp File #

Use Ruby’s built-in Tempfile class to handle this. It creates a temporary file that’s automatically cleaned up when your program exits (or you can delete it manually):

require 'tempfile'

# Generate the PDF content
pdf_content = WickedPdf.new.pdf_from_string('<h1>Hello There!</h1>')

# Create a temporary PDF file
temp_pdf = Tempfile.new(['my_generated_pdf', '.pdf'])
temp_pdf.write(pdf_content)
temp_pdf.close # Important: Close the file to ensure all content is written to disk

# Now you can access the temp file's path
puts temp_pdf.path # Outputs the absolute path to your temporary PDF

2. Use pdf_from_string_to_file (If Your WickedPdf Version Supports It) #

Some versions of WickedPdf include a helper method to write the PDF directly to a file. You can either specify a custom path or pair it with a temp file:

# Option A: Write to a specific path you define
custom_path = '/tmp/my_custom_pdf.pdf'
WickedPdf.new.pdf_from_string_to_file('<h1>Hello There!</h1>', custom_path)

# Option B: Use a temp file path
temp_pdf = Tempfile.new(['temp_pdf', '.pdf'])
WickedPdf.new.pdf_from_string_to_file('<h1>Hello There!</h1>', temp_pdf.path)
puts temp_pdf.path # Retrieve the temp file path

A Quick Note on "Hidden" Background Temp Files #

If you suspected there might be temp files being used behind the scenes, you’re not wrong—WickedPdf may create temporary files internally during the HTML-to-PDF conversion (for assets or intermediate render steps). However, these files are fully managed by the library, deleted immediately after use, and their paths aren’t exposed to your code.

内容的提问来源于stack exchange，提问作者almo