In short I would like to be able to generate a dynamic Rmarkdown report file (pdf or html) from my shiny app with a button click. For this I thought I will use parameterized Report for Shiny. But somehow I can not transfer the single puzzles to the desired aim:
With this code we can generate and download a reactive radarchart in R Shiny:
library(shiny)
library(radarchart)
js <- paste0(c(
"$(document).ready(function(){",
" $('#downloadPlot').on('click', function(){",
" var el = document.getElementById('plot1');",
" // Clone the chart to add a background color.",
" var cloneCanvas = document.createElement('canvas');",
" cloneCanvas.width = el.width;",
" cloneCanvas.height = el.height;",
" var ctx = cloneCanvas.getContext('2d');",
" ctx.fillStyle = '#FFFFFF';",
" ctx.fillRect(0, 0, el.width, el.height);",
" ctx.drawImage(el, 0, 0);",
" // Download.",
" const a = document.createElement('a');",
" document.body.append(a);",
" a.download = 'radarchart.png';",
" a.href = cloneCanvas.toDataURL('image/png');",
" a.click();",
" a.remove();",
" cloneCanvas.remove();",
" });",
"});"
), collapse = "\n")
ui <- pageWithSidebar(
headerPanel('Radarchart Shiny Example'),
sidebarPanel(
checkboxGroupInput('selectedPeople', 'Who to include',
names(radarchart::skills)[-1], selected="Rich"),
actionButton('downloadPlot', 'Download Plot'),
downloadButton('report', 'Generate Report')
),
mainPanel(
tags$head(tags$script(HTML(js))),
chartJSRadarOutput("plot1", width = "450", height = "300"), width = 7
)
)
server <- function(input, output) {
output$plot1 <- renderChartJSRadar({
chartJSRadar(skills[, c("Label", input$selectedPeople)],
maxScale = 10, showToolTipLabel=TRUE)
})
}
shinyApp(ui, server)
What I would like to do is to implement: Generating downloadable reports 
CodePudding user response：
Basically your question already included all the building blocks. I only updated the report template to include the code to plot the radar chart. As a parameter I decided to pass the filtered dataset. In the server I only adjusted the specs for the params:
server <- function(input, output) {
output$plot1 <- renderChartJSRadar({
chartJSRadar(skills[, c("Label", input$selectedPeople)],
maxScale = 10, showToolTipLabel=TRUE)
})
output$report <- downloadHandler(
filename = "report.html",
content = function(file) {
tempReport <- file.path(tempdir(), "report.Rmd")
file.copy("report.Rmd", tempReport, overwrite = TRUE)
params <- list(scores = skills[, c("Label", input$selectedPeople)])
rmarkdown::render(tempReport, output_file = file,
params = params,
envir = new.env(parent = globalenv())
)
}
)
}
Report.Rmd
---
title: "Dynamic report"
output: html_document
params:
scores: NA
---
```{r}
chartJSRadar(params$scores, maxScale = 10, showToolTipLabel=TRUE)
```
