Shiny and RMarkdown: Rendering multiple chunks - shiny

Question

I would like to create a Shiny-RMarkdown app which allows uploading own datasets. Datasets sometimes not only affect one chunk which can be re-rendered by renderPlot() (or similar) but sometimes two or more chunks. See the following example:
---
title: Render multiple chunks
output: html_document
runtime: shiny
---
```{r echo=FALSE}
library(shiny)
fileInput('file1', 'Choose your own CSV File instead of provided
data',accept=c('text/csv', 'text/comma-separated-values,text/plain',
'.csv'))
go1<-reactive({
dpath <- "CurrentBiologyData.txt"
if(!is.null(input$file1)){
dpath <- input$file1$datapath
}
CB.dat <- read.table(dpath, header = TRUE) #choose 'CurrentBiologyData.txt'
plot(CB.dat)
})
```
```{r echo=FALSE}
renderPlot({
go1()
})
```
```{r}
renderPlot({
print(CB.dat)
})
```
So I have three chunks which are affected if I upload a new dataset. The problem is that the third chunk does not see CB.dat which is filled in the first chunk:
Error: Object 'CB.dat' not found
Any ideas how I can make that work?

Answer 1

Applying to your example what I meant in my comment
Put the file reading in a reactive then use it wherever you need it
---
title: Render multiple chunks
output: html_document
runtime: shiny
---
```{r echo=FALSE}
library(shiny)
fileInput('file1', 'Choose your own CSV File instead of provided
data',accept=c('text/csv', 'text/comma-separated-values,text/plain',
'.csv'))
CB.dat<-reactive({
dpath <- "CurrentBiologyData.txt"
if(!is.null(input$file1)){
dpath <- input$file1$datapath
}
read.table(dpath, header = TRUE) #choose 'CurrentBiologyData.txt'
})
```
```{r echo=FALSE}
renderPlot(plot(CB.dat())
```
```{r}
renderTable(CB.dat())
```