Конечно. Таким образом, мы сохраняем цену, получаем новую цену, если цена снижается, делаем текст красным, а затем снова быстро запускаем, чтобы получить эффект fla sh.
Для тестирования я добавил кнопки для имитации роста и уменьшения цены. Я также сделал это проверять изменения чаще.
Длина fla sh может быть изменена в этой строке: invalidateLater(1200).
library(quantmod)
library(shiny)
library(shinydashboard)
library(shinydashboardPlus)
library(shinyWidgets)
ui <- dashboardPage(
dashboardHeader(title = "Example"),
dashboardSidebar(
sidebarMenu(
ID = "tabs",
menuItem(text = "Naspers", tabName = "tabNaspers", icon = icon("chart-line"))
)
),
dashboardBody(
tags$head(tags$style(HTML('.fas { font-size: 36px; }.fas {vertical-align: middle;} #'))),
tabItems(
tabItem(tabName = "tabNaspers",
fluidRow(
column(
width = 7,
boxPlus(title = span("ALL SHARE", style = "color: rgb(128,128,128); font-size: 22px"),
collapsible = TRUE,
closable = FALSE,
enable_dropdown = TRUE,
dropdown_icon = "NULL",
status = 'success',
valueBoxOutput('npn_price', 12),
valueBoxOutput('npn_day_change', 12),
width = 4
)
)
),
#Buttons to simulate stock going up, so that we don't have to wait for the stock to actually go up or down
actionButton('btn_stockgoesup', 'Simulate Stock Going Up'),
actionButton('btn_stockgoesdown', 'Simulate Stock Going Down')
)
)
)
)
npn_close <- 203059.00
server <- function(input, output, session){
autoInvalidate <- reactiveTimer(intervalMs = 6000)
#Buttons to simulate stock going up, so that we don't have to wait for the stock to actually go up or down
observeEvent(input$btn_stockgoesup, {npn_last_stored <<- 0 ; print('At the next update the stock will simulate going up')})
observeEvent(input$btn_stockgoesdown, {npn_last_stored <<- Inf; print('At the next update the stock will simulate going down')})
output$npn_price <- renderUI({
autoInvalidate()
npn_last <- getQuote("NPN.JO", what=yahooQF("Last Trade (Price Only)"))[, 2]
#Handle when app first starts and there is no stored value to compare against
if(exists('npn_last_stored') == FALSE) {npn_last_stored <<- npn_last}
if(npn_last < npn_last_stored) {
#Stock went down
print('stock went down')
npn_color <- 'rgb(220, 50, 20)'
invalidateLater(1200)
} else {
#Stock went up / not changed
print('stock went up / not changed')
npn_color <- 'rgb(0, 0, 0)'
}
#Update stored value
npn_last_stored <<- npn_last
npn_change <- round((npn_last - npn_close) / npn_close, 4) * 100
arrow_color <- ifelse(npn_change > 0, 'rgb(15, 157, 88)' ,'rgb(226, 74, 26)')
npn_diff <- npn_last - npn_close
npn_diff <- ifelse(npn_diff < 0, paste0('-', npn_diff), paste0('+', npn_diff))
tags$div(HTML(paste0('<span style="color:', npn_color, '; font-size: 24px"><strong>', npn_last, '</strong></span>', '<span style="color:', arrow_color, '; font-size: 14px">', npn_diff, '</span>')))
})
output$npn_day_change <- renderUI({
autoInvalidate()
npn_last <- getQuote("NPN.JO", what=yahooQF("Last Trade (Price Only)"))[, 2]
npn_change <- round((npn_last - npn_close) / npn_close, 4) * 100
npn_change <- paste0(npn_change, "%")
arrow_color <- ifelse(npn_change > 0, 'rgb(15, 157, 88)' ,'rgb(226, 74, 26)')
arrow_icon <- ifelse(npn_change < 0, '"fas fa-caret-down"', '"fas fa-caret-up"')
tags$div(HTML(paste0('<i class=', arrow_icon, ' style = "color:', arrow_color,';"></i><span style="color:', arrow_color,'; font-size: 24px"><strong>',npn_change, '</strong></span>')))
})
}
shinyApp(ui, server)