r-调用RShiny服务器调用中的函数，并将结果呈现为打印输出

Question

我写了一个脚本，它使用了两个函数来计算运行测试所需的持续时间，例如功率分析。

输入和编码如下；

## RUN POWER CALCULATION
average_daily_traffic <-  3515/30
control <- 0.47
uplift <- 0.02
num_vars <- 2 
sample_size_calculator <- function(control, uplift){
variant <- (uplift + 1) * control
baseline <- ES.h(control, variant)
sample_size_output <- pwr.p.test(h = baseline,
n = ,
sig.level = 0.05,
power = 0.8)
if(variant >= 0)
{return(sample_size_output)}
else
{paste("N/A")}
}

## RUN DAYS CALCULATOR FUNCTION 
days_calculator <- function(sample_size_output, average_daily_traffic){
days_required <- c((sample_size_output)*num_vars)/(average_daily_traffic)
if(days_required >= 0)
{paste0("It will take ", round(days_required, digits = 0)*num_vars, " days for this test to reach significance, with a daily average of " , round(average_daily_traffic, digits = 0), " visitors to this page over a 30 day period.")}
else
{paste("N/A")}
}

## RUN FUNCTIONS AND OUTPUT ANSWER
sample_size_calculator <- sample_size_calculator(control, uplift)
sample_size_output <-   sample_size_calculator$n
answer <- days_calculator(sample_size_output, average_daily_traffic)
answer

这段代码是高性能的，适合我在独立的R脚本中使用。

然而，我需要在Shiny应用程序中执行这些功能。我的尝试如下：；

library(shiny)
ui <- fluidPage(
actionButton("exe", "Run", 
style="color: #fff; background-color: #337ab7; border-color: #2e6da4"),

mainPanel(
textOutput("answer")
))

server <- function(input, output, session) {
sample_size_calculator <- eventReactive(input$exe,{
average_daily_traffic <-  3515/30
control <- 0.47
uplift <- 0.02
num_vars <- 2 
variant <- (uplift + 1) * control
baseline <- ES.h(control, variant)
sample_size_output <- pwr.p.test(h = baseline,
n = ,
sig.level = 0.05,
power = 0.8)
if(variant >= 0)
{return(sample_size_output)}
else
{paste("N/A")}
})
days_calculator <- eventReactive  (input$exe,{
days_required <- c((sample_size_output)*num_vars)/(average_daily_traffic)
if(days_required >= 0)
{paste0("It will take approximately ", round(days_required, digits = 0)*num_vars, " days or ", round((round(days_required, digits = 0)*num_vars)/365, digits = 1) ," years for this test to reach significance, based on a daily average of " , round(average_daily_traffic, digits = 0), " users to this page in the last 30 days.")}
else
{paste("N/A")}
})
outputs_ <- eventReactive( input$exe, {
req(sample_size_calculator())
req(days_calculator())
sample_size_calculator <- sample_size_calculator(control, uplift)
sample_size_output <-   sample_size_calculator$n

answer <- days_calculator(sample_size_output, average_daily_traffic)
output$answer <- renderText(outputs_$answer) 
})
}

shinyApp(ui = ui, server = server)

当我运行这个代码时，我看到执行按钮，但没有显示任何输出。这很可能是由于我对Shiny如何调用函数的理解受到限制，所以如果有更好的方法，我将非常感激听到它

提前谢谢。

*编辑以包含完整功能代码*

该代码的目的是使用Mark Edmonson的googleAnalyticsR和googleAuthR，从谷歌分析账户检索过去30天内特定URL/页面的网络访问数据，并显示该数据的趋势。一旦用户输入URL并点击"运行"，这种方法就可以正常工作。

还有一个额外的GA调用，用于检索特定转换操作的额外数据(请参阅other_data(。这是为了导出稍后在功率计算中使用的转换率而需要的。

计算为cvr <- aeng$users/totalusers

#options(shiny.port = 1221)

## REQUIRED LIBS 
library(shiny)
library(googleAnalyticsR)
library(plotly)
library(googleAuthR)
library(markdown)
library(pwr)
gar_set_client(scopes = c("https://www.googleapis.com/auth/analytics.readonly"))
daterange <- function(x) {
as.Date(format(x, "%Y-%m-01"))
}
## DATE PARAMETERS 
date_start <- as.Date(Sys.Date(),format='%d-%B-%Y')-31
date_end <- as.Date(Sys.Date(),format='%d-%B-%Y')-1
date_range <- c(date_start, date_end) 

## UI SECTION
ui <- fluidPage(
googleAuth_jsUI("auth"),
tags$head(
tags$link(rel = "stylesheet", type = "text/css", href = "dur_calc.css")
),


tags$br(),
sidebarLayout(
sidebarPanel(
code("To begin, select from 'Accounts' and enter URL of page to be tested:"),
tags$p(),
column(width = 12, authDropdownUI("auth_dropdown", 
inColumns = FALSE)),

textInput("url", label = h5(strong("Page to be tested")), value = "Enter full page URL..."),
hr(),
fluidRow(column(3, verbatimTextOutput("value")
)

),

actionButton("exe", "Run Calculator", 
style="color: #fff; background-color: #337ab7; border-color: #2e6da4"),

),

mainPanel(
plotlyOutput("trend_plot"),
textOutput("page"),
textOutput("answer")
)

)
)


## SERVER SECTION
server <- function(input, output, session) {
auth <- callModule(googleAuth_js, "auth")

## GET GA ACCOUNTS 
ga_accounts <- reactive({
req(auth()
)
with_shiny(
ga_account_list,
shiny_access_token = auth()
)
})

view_id <- callModule(authDropdown, "auth_dropdown", 
ga.table = ga_accounts)

ga_data <- eventReactive( input$exe, {
x <- input$url
#reactive expression
output$page <- renderText({ 
paste("You have selected the page:", input$url) })

filterPageurl <- dim_filter("dimension97" , "REGEX", x ,not = FALSE)
filts <- filter_clause_ga4(list( filterPageurl))
req(view_id())
req(date_range)
with_shiny(
google_analytics,
view_id(),
date_range = date_range, 
dimensions = "date",
metrics = "users",
dim_filters = filts,
max = -1,
shiny_access_token = auth()
)

})
other_data <- eventReactive( input$exe, {
x <- input$url

filterPageurl <- dim_filter("dimension97" , "REGEX", x ,not = FALSE)
filts <- filter_clause_ga4(list( filterPageurl))
seg_id <- "gaid::uzKGvjpFS_Oa2IRh6m3ACg" #AEUs
seg_obj <- segment_ga4("AEUs", segment_id = seg_id)
req(view_id())
req(date_range)
#req(filts)
with_shiny(
google_analytics,
view_id(),
date_range = date_range, 
dimensions = "date",
metrics = "users",
dim_filters = filts,
segments = seg_obj, 
max = -1,
shiny_access_token = auth()
)

})

outputly <- eventReactive( input$exe, {
req(other_data())
req(ga_data())
aeng <- other_data()
ga_data <- ga_data()

totalusers <<- sum(ga_data$users)
cvr <- aeng$users/totalusers

average_daily_traffic <-  totalusers/30
control <- cvr
uplift <- 0.02
num_vars <- 2 
})

sample_size_calculator <- eventReactive(input$exe,{
variant <- (uplift + 1) * control
baseline <- ES.h(control, variant)
sample_size_output <- pwr.p.test(h = baseline,
n = ,
sig.level = 0.05,
power = 0.8)
if(variant >= 0)
{return(sample_size_output)}
else
{paste("N/A")}
})

days_calculator <- eventReactive  (input$exe,{
days_required <- c((sample_size_output)*num_vars)/(average_daily_traffic)
if(days_required >= 0)
{paste0("It will take approximately ", round(days_required, digits = 0)*num_vars, " days or ", round((round(days_required, digits = 0)*num_vars)/365, digits = 1) ," years for this test to reach significance, based on a daily average of " , round(average_daily_traffic, digits = 0), " users to this page in the last 30 days.")}
else
{paste("N/A")}
})

output$trend_plot <- renderPlotly({
req(ga_data())
ga_data <- ga_data()
plot_ly(
x = ga_data$date,
y = ga_data$users, 
type = 'scatter',
mode = 'lines') %>%
layout(title = "Page Visitors by Day (last 30 days)",
xaxis=list(title="Date", tickformat='%Y-%m-%d', showgrid=FALSE, showline=TRUE),
yaxis=list(title = "Users", showgrid=FALSE, showline=TRUE)
)

})

calc_answer <- eventReactive(input$exe, {
req(outputly)
outputly <- outputly()
sample_size_calculator <- sample_size_calculator()
sample_size_output <- sample_size_calculator$n
days_calculator(sample_size_output, average_daily_traffic)
})
output$answer <- renderText(calc_answer()) 


}
shinyApp(ui = ui, server = server)

Answer 1

一些可能有所帮助的建议。

• 在添加所有计算之前，将从一个简化的闪亮应用程序开始，现在可能更容易使用
• 将避免将output语句放入eventReactive中。请参见以下示例
• 考虑按钮按下时只有一个observeEvent或eventReactive，而不是多个，特别是因为某些功能的结果取决于其他功能
• 现在没有输入，所以不需要额外的reactive表达式。不过，当您添加输入时，您可能会添加

如果您还没有，请查看R Studio Shiny关于动作按钮和反应性的教程。

希望这对今后的发展有所帮助。

library(shiny)
library(pwr)
ui <- fluidPage(
actionButton("exe", "Run", style="color: #fff; background-color: #337ab7; border-color: #2e6da4"),
mainPanel(
textOutput("answer")
)
)
server <- function(input, output, session) {
average_daily_traffic <-  3515/30
control <- 0.47
uplift <- 0.02
num_vars <- 2 
sample_size_calculator <- function() {
variant <- (uplift + 1) * control
baseline <- ES.h(control, variant)
sample_size_output <- pwr.p.test(h = baseline,
n = ,
sig.level = 0.05,
power = 0.8)
if(variant >= 0)
{return(sample_size_output)}
else
{return(NA)}
}
days_calculator <- function (sample_size_output, average_daily_traffic) {
days_required <- c((sample_size_output)*num_vars)/(average_daily_traffic)
if(days_required >= 0)
{paste0("It will take approximately ", round(days_required, digits = 0)*num_vars, " days or ", round((round(days_required, digits = 0)*num_vars)/365, digits = 1) ," years for this test to reach significance, based on a daily average of " , round(average_daily_traffic, digits = 0), " users to this page in the last 30 days.")}
else
{paste("N/A")}
}
calc_answer <- eventReactive(input$exe, {
sample_size_calculator <- sample_size_calculator()
sample_size_output <- sample_size_calculator$n
days_calculator(sample_size_output, average_daily_traffic)
})
output$answer <- renderText(calc_answer()) 
}
shinyApp(ui = ui, server = server)