Redraw shiny plot after updating data frame? - r

Question

I have built a Shiny app with a database backend -
Im trying to reload the dataframe current_data_frame and redraw the plot using it when input$draw_plot (action button) is pressed.
I am having trouble re-drawing the plot after recalling the data frame?
Any ideas what I am missing??
snippet from server.R
current_data_frame = data.frame(matrix(ncol = 4, nrow = 0))
names( current_data_frame ) <- c("sample_id", "call", "intensity_A" , "intensity_B")
# OBSERVE BUTTON PRESS & UPDATE DATA FRAME
observeEvent( input$draw_plot, {
current_data_frame <- get_data_frame( input$probeset_id , input$study_id , input$batch_id)
})
vals <- reactiveValues(
keeprows = rep(TRUE, nrow( current_data_frame ))
)
output$call_plot <- renderPlot({
# Lists for holding unactive_points
keep <- current_data_frame[ vals$keeprows, , drop = FALSE]
exclude <- current_data_frame[ !vals$keeprows, , drop = FALSE]
# Le plot
ggplot(keep, aes( intensity_A , intensity_B)) +
geom_point(aes(colour = factor(call), shape = factor(call)) ) #+
#geom_point(data = exclude, shape = 21 , fill = NA, colour = "black", alpha = 0.25)
})
# Toggle click points
observeEvent( input$call_plot_click, {
res <- nearPoints(current_data_frame, input$call_plot_click, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Toggle points that are brushed when clicked
observeEvent(input$exclude_toggle, {
res <- brushedPoints(current_data_frame, input$call_plot_brush, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Reset all points
observeEvent( input$exclude_reset, {
vals$keeprows <- rep( TRUE, nrow(current_data_frame))
})
})

Answer 1

You probably need to make current_data_frame a reactive value. You can either do that by returning it inside of a reactive or by adding it to your vals object, including using vals$current_data_frame everywhere you currently use current_data_frame and changing vals to look something like this:
vals <- reactiveValues(keeprows = rep(TRUE, nrow( current_data_frame )),
current_data_frame = current_data_frame
)
which will set vals$current_data_frame to the default you defined at the start of your code the first time, then allow you to change it every time the observeEvent is triggered.

Answer 2

Managed to answer this myself -
Wrapped the whole output$call_plot in the response function. Now it redraws + fetches new data each time the button is pressed.
Code below...
observeEvent( input$draw_plot, {
current_data_frame <- get_data_frame( input$probeset_id , input$study_id , input$batch_id)
vals <- reactiveValues(
keeprows = rep(TRUE, nrow( current_data_frame ))
)
output$call_plot <- renderPlot({
# Lists for holding unactive_points
keep <- current_data_frame[ vals$keeprows, , drop = FALSE]
exclude <- current_data_frame[ !vals$keeprows, , drop = FALSE]
# Le plot
ggplot(keep, aes( intensity_A , intensity_B)) +
geom_point(aes(colour = factor(call), shape = factor(call)) ) #+
#geom_point(data = exclude, shape = 21 , fill = NA, colour = "black", alpha = 0.25)
})
# Toggle click points
observeEvent( input$call_plot_click, {
res <- nearPoints(current_data_frame, input$call_plot_click, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Toggle points that are brushed when clicked
observeEvent(input$exclude_toggle, {
res <- brushedPoints(current_data_frame, input$call_plot_brush, allRows = TRUE)
vals$keeprows <- xor(vals$keeprows, res$selected_)
})
# Reset all points
observeEvent( input$exclude_reset, {
vals$keeprows <- rep( TRUE, nrow(current_data_frame))
})
})
})