Rmarkdown that can be run interactively or render to static output

gistfile1.txt

---
title: "Report that can be run interactively or rendered to static output"
output:
  html_document:
    toc: yes
    toc_float:
      collapsed: no
      smooth_scroll: no
    toc_depth: 5
    css: "./style/css/markdown.css"
    df_print: paged
  pdf_document:
    toc: yes
    toc_depth: '5'
runtime: shiny
params:
    row: 1
---


This RMarkdown report can be run interactively or rendered to static output using the following commands:

### Running interactively:
Use `rmarkdown::run()` to launch the report with a Shiny runtime:
```{r, eval=FALSE}
rmarkdown::run("report.Rmd")
```

### Rendering to static output:
Use `rmarkdown::render()` for a static document rendering:
```{r, eval=FALSE}
rmarkdown::render("report.Rmd", params = list(row = 5))
```

```{r, echo = FALSE, collapse=FALSE, message = FALSE, warning = FALSE}
library(shiny)

# setup to allow both interactive shiny and static rendering
if (! shiny::isRunning()) {
  input <- params
  
  # for a static render monkey shiny functions
  assign(
    "reactive",
    function(expr, ...) {
      function() eval(expr, envir = parent.frame())
    },
    envir = globalenv()
  )

  # loop over useful shiny functions and monkey them
  shiny_fns <- ls(envir = asNamespace("shiny"), all.names = TRUE)
  for (nm in shiny_fns) {
    # patch all render* functions to evaluate & print
    if (grepl("^render", nm)) {
      assign(nm,
             function(expr, ...) {
               val <- eval(expr, envir = parent.frame())
               print(val)
             },
             envir = globalenv()
      )
    }
    # stub out all *Input() and *Output() calls so they don't error
    if (grepl("(Input|Output)$", nm)) {
      assign(nm,
             function(...) NULL,
             envir = globalenv()
      )
    }
  }
}
```

```{r, echo = FALSE}
selectInput("row", "Select row:",
            choices = 1:10,
            selected = params$row)

foo <- reactive({paste("This is row", input$row)})

renderPrint({foo()})
```