Quero que a tabela e o gráfico de barras gerados pelo meu aplicativo brilhante possam ser baixados como um relatório em PDF. Posso gerar o relatório com as entradas selecionadas na primeira vez em que inicio o aplicativo no meu computador local, mas quando troco as entradas, ele não gera os relatórios das novas entradas em pdf.

Aqui está o meu código da interface do usuário

require(shiny)
require(shinydashboard)
require(ggplot2)
require(ggthemes)

sample <- read.csv("new_sample2.csv", stringsAsFactors = FALSE)

header <- dashboardHeader(title = "XYZ School Student Dashboard", titleWidth = 370)

body <- dashboardBody(
tags$head(tags$style(HTML('
  .main-header .logo {
                        font-family: "Georgia", Times, "Times New Roman", serif;
                        font-weight: bold;
                        font-size: 20px;
                        }
                        '))),
fluidRow(
column(width = 9,
box(title = "Selected Student", width = NULL, solidHeader = TRUE, status = "info",
           textOutput("summary1"),
           textOutput("summary2"),
           textOutput("summary3")
),

       box(title = "Marks card", status = "info", width = NULL, solidHeader = TRUE, collapsible = TRUE,
           tableOutput("table")),
       box(title = "Marks card bar plot", status = "info", width = NULL, solidHeader = TRUE, collapsible = TRUE,
           plotOutput("plot"))
),

column(width = 3,
       box(title = "Select", background = "blue" ,width = NULL,
           selectInput("class", "Class", unique(sample$class)),
           selectInput("name", "Name", unique(sample$name)),
           selectInput("exams", "Exams", choices = c("1st Periodic Test", "1st Term", "2nd Periodic Test",
                                                     "2nd Term", "3rd Periodic Test", "4th Periodic Test",
                                                     "Final")),

           "Note: In the Bar Plot", 
           br(),
           "1. The black line is the average class mark for that particular subject.",
           br(),
           "2. The red line is the pass mark for that particular subject.",
           hr(),
           downloadButton("downloadReport", "Download report")
           )
       )
  )
)


ui <- dashboardPage(skin = "blue",
    header,
      dashboardSidebar(disable = TRUE),
        body
)  

E aqui está o código do meu servidor

server <- function(input, output, session){

output$summary1 <- renderText({
paste("Student Name: ", input$name)
})

output$summary2 <- renderText({
paste("Class: ", input$class)
})
output$summary3 <- renderText({
paste("Examination: ", input$exams)
})


getdataset <- reactive({
dataset <- sample[sample$class == input$class & sample$name == input$name & sample$examination == input$exams, ]
})

observe({
classInput <- input$class
updateSelectInput(session, "name", choices = sample$name[sample$class == classInput])
})

output$table <- renderTable({
dataset <- getdataset()
dataset[, c("date", "subject", "maximum_mark", "pass_mark", "obtain_mark", "class_ave", "pc", "exam_pc")]
})

plotInput <- reactive({
df <- getdataset()
ggplot(df, aes(x = subject, y = obtain_mark)) +
  theme_fivethirtyeight() +
  geom_bar(stat = "identity", fill = "#006699") +
  geom_text(aes(label = obtain_mark),vjust = -0.4) +
  geom_errorbar(data = getdataset(),
                aes(y = class_ave, ymax = class_ave,
                    ymin = class_ave), colour = "#000000") +
  geom_errorbar(data = getdataset(),
                aes(y = pass_mark, ymax = pass_mark,
                    ymin = pass_mark), colour = "red") +
  labs(title = paste(input$name,"'s", input$exams, "marks"), x = "", y = "Marks") +
  theme(axis.text=element_text(size=10, face = "bold")
  )
})

output$plot <- renderPlot({
print(plotInput())
 })

output$downloadReport <- downloadHandler(
filename = "Student-report.pdf",
content = function(file){
  inputEnv <- new.env()
  inputEnv$class <- input$class
  inputEnv$name <- input$name
  inputEnv$exams <- input$exams
  inputEnv$data <- getdataset()
  out = rmarkdown::render("student_report.Rmd", envir = inputEnv)
  file.rename(out, file)
     }
    )
   }

 shinyApp(ui, server)  

Este é o arquivo .Rmd que eu coloquei na mesma pasta em que app.R está.

---
title: "school_report"
author: "Management"
date: "May 4, 2016"
output: pdf_document
---

```{r echo=FALSE}
plotInput()
```  

```{r echo=FALSE}
dataset <- getdataset()
dataset[, c("date", "subject", "maximum_mark", "pass_mark", "obtain_mark", "class_ave", "pc", "exam_pc")]
```  

Os dados são uma amostra de notas obtidas pelos alunos em exames realizados pela escola.

head(sample)
 class   name       examination       date        subject maximum_mark pass_mark obtain_mark  pc class_ave
1   1 Adison 1st Periodic Test 2015-03-23      English-I        20         8          14     70      15
2   1 Adison 1st Periodic Test 2015-03-24    Mathematics        20         8          19     95      16
3   1 Adison 1st Periodic Test 2015-03-25        Science        20         8          18     90      12
4   1 Adison 1st Periodic Test 2015-03-26          Hindi        20         8          20    100      15
5   1 Adison 1st Periodic Test 2015-03-27 Social Studies        20         8          19     95      11
6   1 Adison 1st Periodic Test 2015-03-28            M.M        20         8          20    100      14
 exam_pc
1 92.86
2 92.86
3 92.86
4 92.86
5 92.86
6 92.86  

tail(sample)
     class   name examination       date       subject maximum_mark pass_mark obtain_mark  pc class_ave
1851   2   Denver       Final 2015-12-10    English-II          100        40          93  93        59
1852   2   Denver       Final 2015-12-02       Drawing           50        20          25  50        34
1853   2   Denver       Final 2015-11-30            GK           50        20          50 100        42
1854   2   Denver       Final 2015-12-01 Moral Science           50        20          50 100        41
1855   2   Denver       Final 2015-12-02     Dictation           25        10          25 100        20
1856   2   Denver       Final 2015-11-30  Hand Writing           25        10          25 100        20
       exam_pc
 1851   87.89
 1852   87.89
 1853   87.89
 1854   87.89
 1855   87.89
 1856   87.89  

Eu realmente apreciaria sua ajuda.