[SOLVED] How to download pdf generated with rmarkdown via HTTP using OpenCPU

How to download pdf generated with rmarkdown via HTTP using OpenCPU

I'm trying to download a pdf that I've created in a R backend using rmarkdown, but I'm not sure how to retrieve it back via HTTP, if that's even possible. I'm using Angular6 in the front-end and I'm just using basic GET/POST methods to communicate with my backend.

Here is some code related to this question:

Backend code (R):

EXPORT <- function(results){ library(rmarkdown) library(knitr) rmarkdown::render("genepanel.Rmd", output_format = "pdf_document", params = list(results = results)) }

Front-end code (Angular TypeScript):

this.http.post(environment.API + '/R/EXPORT/json', results) .subscribe(result => console.log(result));

I don't get any HTTP error when calling the service and the pdf is generated if I manually run the code in the server.

Thanks in advance!

Solution

You should call the API without the /json postfix. You will see an index generated resources and the pdf file should be in there.

Your client should check the Location response header from the POST request to /R/EXPORT which will contain the location of the session, and you can get the pdf from there.