How to insert an external ressource within a PDF dcument?

问题

I would like to create a document (possibly PDF) that contains an image. The main goal is to have that image (or any external ressource) downloaded over http, from within an external server.

Step 1. Create the pdf document that includes a reference to an external ressource (eg. image URL)

Step 2. When the file is opened the ressource is loaded

Step 3. An http request is fired. Example : GET https://myserver/ressources/image_to_include.png HTTP/1.1

I can obviously insert an image into a pdf document, though I can't have something loaded "at runtime", as it would be with an html page for example.

Any ideas?

来源：https://stackoverflow.com/questions/58594681/how-to-insert-an-external-ressource-within-a-pdf-dcument