Can I pass a variable to the downloadthis command?

[daranzolin]

Thanks again for creating this extension!

The example has this command:

{{< downloadthis files/mtcars.csv dname="mtcars.csv" label="Download the mtcars data" icon="database-fill-down" type="info" >}}

Where 'files/mtcars.csv' is a path to an existing file.

I'd love to pass the data frame directly, e.g. 'mtcars' instead of 'files.mtcars.csv'. Is this a possibility? If not, is it possible to pass a file path as a variable created within the quarto document? E.g.:

p <- path("mtcars", ext = "csv")

{{< downloadthis p dname="mtcars.csv" label="Download the mtcars data" icon="database-fill-down" type="info" >}}

[daranzolin]

Ah, with some experimentation I can do:

path <- fs::path("mtcars", ext = "csv")
cmd <- paste('{{< downloadthis', path, 'dname=Mtcars label="Download the mtcars data" icon=database-fill-down type=info class=data-button id=mtcars >}}')

Then:

#| results: asis
cat(cmd)

This works for my purposes, but passing in the data frame object directly would be ideal.

[shafayetShafee]

No! I am afraid It is not possible to pass R data.frame directly to the downloadthis shortcode 🙁, since the shortcode is internally handled by Lua.

However, your solution to this problem can be made easier by implementing inline R code. Try the following reprex,

---
title: "Downloadthis Example"
format: html
---

## data.frame in downloadthis

### Approach 01

Assuming you have iris.csv file in the same directory as this qmd file, you can refer 
the path of the csv using inline r code as follows,

{{< downloadthis `r fs::path("iris.csv")` dname=iris label="Download the iris data" icon=database-fill-down type=info class=data-button id=iris >}}


### Approach 02

You can write a function that takes a data.frame object and then writes the data.frame
then writes the data.frame in the current directory as a csv file then returns the
path to the csv file.

```{r}
#| echo: false
embed_df <- function(data, name) {
  readr::write_csv(data, paste0(name, ".csv"))
  fs::path(name, ext="csv")
}
```

Then call the function inside the downloadthis shortcode using inline R code.

{{< downloadthis `r embed_df(mtcars, "mtcars")` dname=Mtcars label="Download the mtcars data" icon=database-fill-down type=info class=data-button id=mtcars >}}

Let me know if anything is unclear 🙂.

[daranzolin]

That's great, thanks!