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Render source data related statistics

updating-data-statistics.Rd

The function should assign rendering that displays data source statistics to the valid output. By default, the output is placed within .render_filters method.

Usage

.update_data_stats(source, ...)

# S3 method for default
.update_data_stats(source, step_id, cohort, session, ...)

# S3 method for tblist
.update_data_stats(source, step_id, cohort, session, ...)

Arguments

source

Source object.

...

Extra arguments passed to a specific method.

step_id

Id if filtering step.

cohort

Cohort object.

session

Shiny session object.

Value

No return value, used for side effect which assigning Cohort data statistics to the `output` object.

Details

When rendering the output, a good practice is to use cached data statistics available with `cohort$get_cache(step_id)`. This way, you omit running additional computations which results with performance improvement.

See also

source-gui-layer

Examples

if (interactive()) {
  library(magrittr)
  library(shiny)
  library(cohortBuilder)
  library(shinyCohortBuilder)

  ui <- fluidPage(
    sliderInput("step_two_max", "Max step two copies", min = 6, max = 12, value = 8),
    uiOutput("2-stats_books")
  )

  server <- function(input, output, session) {
    coh <- cohort(
      set_source(as.tblist(librarian)),
      step(
        filter(
          "range", id = "copies", dataset = "books",
          variable = "copies", range = c(5, 12)
        )
      ),
      step(
        filter(
          "range", id = "copies", dataset = "books",
          variable = "copies", range = c(6, 8)
        )
      )
    ) %>% run()
    coh$attributes$stats <- c("pre", "post")
    observeEvent(input$step_two_max, {
      coh$update_filter("copies", step_id = 2, range = c(6, input$step_two_max))
      run(coh, min_step_id = "2")
      .update_data_stats(coh$get_source(), step_id = "2", cohort = coh, session = session)
    })
  }

  shinyApp(ui, server)
}