【发布时间】：2020-03-12 00:20:46
【问题描述】：
几周以来，我一直在尝试为似乎与此discussion 相关的常见用例提出解决方案，但没有成功。这段对话最接近于解释如何在 Shiny 应用程序中创建和使用全局变量——但我很难理解所提供代码的细微差别。 这篇 SO 帖子很相似，但并不完全是我感到困惑的地方：
全局配置文件问题
我们有一个应用程序可以引导用户完成“向导设置” 介绍，允许他们配置某些参数，这些参数会影响多个应用程序 flexdashboard 中单个 Shiny 应用程序模块的功能。这些需要全局存储，传递到子应用程序中，并且需要在“配置文件”应用程序中进行修改在全局级别，以便对全局配置文件所做的更改会修改其他模块的功能因此。
我正在尝试理解这篇文章中提供的代码并使其适应这个用例，但到目前为止我还无法确定如何去做。任何帮助将不胜感激！
---
title: "Global Profile Reprex"
output:
flexdashboard::flex_dashboard:
orientation: columns
vertical_layout: fill
runtime: shiny
---
```{r setup, include=FALSE}
library(flexdashboard)
library(shiny)
library(magrittr)
Global <- function(input, output, session) {
profile <- reactiveValues(goal = 5)
return(profile)
}
Module1 <- function(input, output, session, globals) {
goal = globals$profile
}
```
Column {data-width=500}
-----------------------------------------------------------------------
### Access
```{r 'Access'}
# This is just intented to access the global reactive values
ui <- renderUI(fluidPage(
shiny::htmlOutput("viewProfile")
))
server <- function(input, output, session) {
globalProfile <- callModule(Global, "global")
output$viewProfile <- shiny::renderText({
paste0("Goal:",globalProfile$profile$goal)
})
}
# Run the application
shinyApp(ui = ui, server = server)
```
Column {data-width=500}
-----------------------------------------------------------------------
### Update
```{r 'Update'}
# This is intended to allow a user to update the global reactive values.
ui <- renderUI(fluidPage(
fluidRow(width = 12,
column(12,
textInput(inputId = "goal",
label = "Goals (time per week)",
placeholder = "ex 4h42m 4:42"))),
fluidRow(width = 12,
column(5), column(2, submitButton("Save Changes", icon("save", lib = "font-awesome"))),
column(5)) ,
shiny::htmlOutput("test.text")
))
# Define server logic required to draw a histogram
server <- function(input, output, session) {
globalProfile <- callModule(Global, "global")
reactive({
print("profile Saved")
mod1 <- callModule(Module1, "mod1", globalProfile)
mod1$profile$goal <- input$goal
})
output$test.text <- shiny::renderText({
c("Goal",globalProfile$profile$goal) %>% paste0(collapse = " ")
})
}
# Run the application
shinyApp(ui = ui, server = server)
```
R version 3.5.3 (2019-03-11)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 18362)
Matrix products: default
locale:
[1] LC_COLLATE=English_United States.1252
[2] LC_CTYPE=English_United States.1252
[3] LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C
[5] LC_TIME=English_United States.1252
attached base packages:
[1] stats graphics grDevices utils datasets methods base
other attached packages:
[1] magrittr_1.5 shiny_1.4.0.9000 RevoUtils_11.0.3
[4] RevoUtilsMath_11.0.0
loaded via a namespace (and not attached):
[1] Rcpp_1.0.3.1 pillar_1.4.2
[3] compiler_3.5.3 later_1.0.0
[5] plyr_1.8.4 tools_3.5.3
[7] digest_0.6.22.3 packrat_0.4.9-3
[9] lubridate_1.7.4.9000 jsonlite_1.6.9000
[11] evaluate_0.14 tibble_2.1.3
[13] gtable_0.2.0 pkgconfig_2.0.3
[15] rlang_0.4.1 rstudioapi_0.10.0-9000
[17] yaml_2.2.0 xfun_0.11.1
[19] fastmap_1.0.1 withr_2.1.2
[21] dplyr_0.8.3 httr_1.4.1.9000
[23] knitr_1.26 grid_3.5.3
[25] tidyselect_0.2.5 flexdashboard_0.5.1.9000
[27] glue_1.3.1.9000 R6_2.4.1
[29] rmarkdown_1.17 ggplot2_3.1.0
[31] purrr_0.3.3.9000 promises_1.1.0.9000
[33] scales_1.0.0.9000 htmltools_0.4.0.9000
[35] rsconnect_0.8.13 assertthat_0.2.1
[37] xtable_1.8-4 mime_0.7
[39] colorspace_1.4-0 httpuv_1.5.2.9000
[41] lazyeval_0.2.1 munsell_0.5.0
[43] crayon_1.3.4
访问函数适用于这个简化的代码，但我仍然无法弄清楚如何从更新应用程序内部更新全局反应值。
---
title: "Global Profile Reprex"
output:
flexdashboard::flex_dashboard:
orientation: columns
vertical_layout: fill
runtime: shiny
---
```{r setup, include=FALSE}
library(flexdashboard)
library(shiny)
library(magrittr)
profile <- reactiveValues(goal = 5)
Module1 <- function(input, output, session, globals) {
goal = globals$profile
}
```
Column {data-width=500}
-----------------------------------------------------------------------
### Access
```{r 'Access'}
# This is just intented to access the global reactive values
ui <- renderUI(fluidPage(
shiny::htmlOutput("viewProfile")
))
server <- function(input, output, session) {
output$viewProfile <- shiny::renderText({
paste0("Goal:", profile$goal)
})
}
# Run the application
shinyApp(ui = ui, server = server)
```
Column {data-width=500}
-----------------------------------------------------------------------
### Update
```{r 'Update'}
# This is intended to allow a user to update the global reactive values.
ui <- renderUI(fluidPage(
fluidRow(width = 12,
column(12,
textInput(inputId = "goal",
label = "Goals (time per week)",
placeholder = "ex 4h42m 4:42"))),
fluidRow(width = 12,
column(5), column(2, submitButton("Save Changes", icon("save", lib = "font-awesome"))),
column(5)) ,
shiny::htmlOutput("test.text")
))
# Define server logic required to draw a histogram
server <- function(input, output, session) {
reactive({
print("profile Saved")
profile$goal <<- input$goal
})
output$test.text <- shiny::renderText({
c("Goal: ",profile$goal) %>% paste0(collapse = " ")
})
}
# Run the application
shinyApp(ui = ui, server = server)
```
【问题讨论】：
标签： r shiny scoping flexdashboard shiny-reactivity