rmarkdown::run with multiple shiny_prerendered documents

[aronatkins]

Using rmarkdown 2.6

Given a directory with multiple Rmd containing runtime: shiny_prerendered, only one of the documents is served by rmarkdown::run. This behavior is different than we see with multiple runtime: shiny documents.

First file (named empty.Rmd):

---
title: "empty.Rmd"
output: html_document
runtime: shiny_prerendered
---

[second](second.Rmd)

```{r, echo=FALSE}
textOutput("message")
```

```{r, context="server"}
output$message <- renderText({
  "This is the empty.Rmd file"
})
```

Second file (named second.Rmd):

---
title: "second.Rmd"
output: html_document
runtime: shiny_prerendered
---

[empty](empty.Rmd)

```{r, echo=FALSE}
textOutput("message")
```

```{r, context="server"}
output$message <- renderText({
  "This is the second.Rmd file"
})
```

Launch the content with:

rmarkdown::run(file=NULL, dir=".")

Only one of the two files is served. In my case, it was always empty.Rmd (the alphabetically first file).

Both documents can be served if you change runtime: shiny_prerendered to runtime: shiny.

The expectations for rmarkdown::run (at least for runtime: shiny documents):

• http://127.0.0.1:6500/ should serve one of the two applications (based on existing rmarkdown::run rules).
• http://127.0.0.1:6500/empty.Rmd should serve the empty.Rmd application.
• http://127.0.0.1:6500/second.Rmd should serve the second.Rmd application.

---

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[cderv]

Hi @aronatkins,

I think this is a duplicate of #1576 which I recently asked @schloerke about. It is currently the way prerendered document are working as it will pre render the app UI before running based on one Rmd (or html) file.

Currently, the document to serve at the root url if not provided (default_file) is

• The Rmd file if there is only one OR
• index.Rmd or ui.Rmd (first one found) OR
• First Rmd (alphetically ordered) with a shiny* runtime. OR
• index.html or ui.html OR
• the file provided

This logic is the same for both runtime but with prerendered not being able to render according to a new route as with runtime shiny (which render on the run unlike pre rendered). it seems only one Rmd makes sense for shiny prerendered document.

So this is definitly something to look into with the help of the shiny team if we want to support this.