在Shiny中，如何直接将源代码替换为R函数调用或语句？

Question

Right now, I'm coding in Shiny, the web-app creation framework written in R, and I use the app.R format for my Shiny app, which mean I have two variables that I pass to Shiny::runapp(ui, server) . The code for the server looks like this:

#SERVER CODE: INCLUDE YOUR SOURCE FILES BELOW
server <- function(input, output, session) {
  source("mod_input.R", local=TRUE)
  source("mod_normalization.R", local=TRUE)
  source("mod_outlier.R", local=TRUE)
}

These source files contain code like this:

output$outlier_PCA <- renderPlot({
  withProgress(message='Creating PCA plot...', {
    if(!is.null(rval$outlier_rw)) {
      rwl <<- logTrans(rval$outlier_rw)
      print(mdl_pca(rwl) + ggtitle("Principal Component Analysis Graph (Retained Data)"))
    }
  })
})

...which is pretty standard--I output my ggplot2 graphs to variables that are "features" of the general output variable that Shiny processes and sends to the output.

The other half of a Shiny app is the UI:

ui <- navbarPage("test app",

  ###INPUT MODULE
  tabPanel("Data Input",

    ##ROW 1
    fluidRow(
      column(12,
          #FILE UPLOAD
          tabsetPanel("Upload files",
            tabPanel("Upload Raw Data",
               fileInput("rw_file",label = "Raw Sample Counts (CSV)"),
               fileInput("srr_file", label= "Experiment-Sample Metadata (CSV) \n[Optional]"),
               fileInput("srx_file", label= "Experiment Summary (CSV) \n[Optional]"),
               actionButton("submit_raw_data", label='Submit data')
            ),
            #DATA PREVIEW
            tabPanel("Preview Raw Data",
              DT::dataTableOutput("rw_preview",  width = "auto", height="auto"),
              uiOutput("rw_preview_range"),
              uiOutput("grab_rw_preview_range")
            ),
            #NORMALIZED DATA PREVIEW
            tabPanel("Preview Normalized Data",
               DT::dataTableOutput("norm_preview",  width = "auto", height="auto"),
               uiOutput("norm_preview_range"),
               uiOutput("grab_norm_preview_range")
            )
          )
      )
    )
    ##ROW 2
  ),
  ###END INPUT MODULE

  ###OUTLIER REMOVAL MODULE
  tabPanel("Outlier Removal",
           column(4,
                  wellPanel(
                    tabsetPanel("Settings",
                                tabPanel("Filter data",
                                         sliderInput(inputId = "outlier_zscore", "Resistant Z-score Sample Threshold",
                                                     min=0, max=10.0,
                                                     value=2.0, step=0.01),
                                         actionButton(inputId = "grab_outlier_zscore", "Filter data")
                                ),
                                tabPanel("Sample Boxplot",
                                         uiOutput("outlier_preview_range") ,
                                         actionButton(inputId = "grab_outlier_preview_range", "View samples")
                                )
                    )
                  ),
                  plotOutput("outlier_PCA")
           ),
           column(8,
                  plotOutput("outlier_boxplot"),
                  plotOutput("outlier_density")
           )
  )
  ###END OUTLIER REMOVAL MODULE
)

Now, I want to compartmentalize each part of the UI that corresponds to a certain module in this app, but I can't simply do the same thing like I did with server and source("filename.R", local=TRUE) . It simply doesn't work.

Is there another option I can use for directly substituting source code from a file directly into a R function/statement?

Answer 1

Since @DavidRobinson didn't provide an answer, I will summarize his solution:

The best way to accomplish this is to simply assign the output of the UI component functions as variables, and then to directly include these variables in the larger UI function itself.

ui_input <- 
tabPanel("Data Input",
 ##ROW 1
 fluidRow(...and so on...


ui <- navbarPage("Shiny App",
  ui_input
)