How do I connect fileInput to ggplot in Shiny? - r

Question

I have been working on this for more than 6 hours today, and I know it's a simple issue, but I can't figure it out. What I want is to input a file, and then be able to use multiple selectInput dropdown menus to change the output on the ggplot. Here is what I have so far:
UI:
ui = dashboardPage(
dashboardHeader(title = "Apple Financials"),
dashboardSidebar(
fileInput("file1", label = "Upload SAS Data:", accept = ".sas7bdat"),
selectInput("x", label = "X-Axis Variable", choices = c("Sales", "Cash", "Assets", "Profits", "R&D", "SG&A")),
selectInput("y", label = "Y-Axis Variable", choices = c("Sales", "Cash", "Assets", "Profits", "R&D", "SG&A"), selected = "R&D"),
selectInput("scale", label = "Choose the Scale:", choices = c("Levels", "Log 10")),
radioButtons("model", label = "Choose the Model:", choices = c("Linear Model", "LOESS", "Robust Linear", "None"), selected = "LOESS"),
checkboxInput("ribbon", label = "Standard Error Ribbon", value = TRUE),
conditionalPanel(
condition = "input.model == 'LOESS'",
sliderInput("span", label = "Span for LOESS", min = 0, max = 1, value = .75)
)
),
dashboardBody(
box(width = NULL, height = 415, plotOutput("plots"))
)
)
Server:
server = function(input, output) {
observe({
data = input$file1
if(is.null(data))
return(NULL)
df = read_sas(data$datapath)
output$plots = renderPlot({
ggplot(df, aes(x = input$x, y = input$y)) +
geom_line()
})
})
}

Answer 1

As the input is a string, we need aes_string in ggplot
server = function(input, output) {
observe({
data = input$file1
if(is.null(data))
return(NULL)
df = read_sas(data$datapath)
output$plots = renderPlot({
ggplot(df, aes_string(x = input$x, y = input$y)) +
geom_line()
})
})
}
shinyApp(ui, server)
NOTE: For demonstration, we are uploading a csv file instead of SAS file