R blastula external parametrization

Question

I did not sucsseed to parametrize Rmd blastula document from external R script. I tried many combinations, but it seems, that I am missing some part.

Example:

blastula_test.Rmd

```
---
title: Useful graph!
output: blastula::blastula_email
params:
  Param_list: Param_list
---

bla bla

```{r}

str(params$Param_list)

external_R_script.R

library(blastula)

tab <- data.frame(A=seq(5),B=rev(seq(5)))

my_email_object <- render_email("blastula_test.Rmd", 
                                output_options = list(params=list(Param_list =tab)))

Output: (it returns the specified in yaml character string(Param_list) and not the transmitted **tab**)

bla bla

str(params$Param_list)
##  chr "Param_list"

Desired output: It should return the structure of the **tab** data frame.

bla bla

str(params$Param_list)
'data.frame':   5 obs. of  2 variables:
 $ A: int  1 2 3 4 5
 $ B: int  5 4 3 2 1

Could you please help me to parametrize correctly the file.

It looks, that render_email function is not working as expected.