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Server logic for the dataFilter module

Source: R/dataFilter_module_server.R
dataFilterServer.Rd

Renders an interactive DT table with column-level filters and returns a reactive containing only the currently visible (filtered) rows. This reactive can be passed directly to any plotting module as its data argument.

Usage

dataFilterServer(
  id,
  data,
  factor.char.cols = TRUE,
  page.length = 10,
  col.visibility = FALSE,
  hide.columns = NULL,
  filter.max.options = 50
)

Arguments

id

The ID for the Shiny module. Must match the id used in dataFilterUI().

data

A reactive containing the data frame to display and filter. Values that are not data frames are coerced with as.data.frame(); a NULL value is treated as "not ready yet" and the table waits for data.

factor.char.cols

Logical. When TRUE, all character columns in data are converted to factors before the table is rendered. This causes DT to display select-box filters for those columns instead of free-text search boxes. Note that DT serialises every level of a factor column into the page, so this is best avoided for columns with very many distinct values. Defaults to TRUE.

page.length

Integer. The default number of rows shown per page. Defaults to 10.

col.visibility

Logical. When TRUE, adds a DT "Columns" button (Buttons extension colvis) so users can show/hide individual columns. Defaults to FALSE.

hide.columns

Character vector of column names (or a numeric vector of column positions) to hide when the table is first drawn. Hidden columns get no filter box, which keeps the interface focused on the columns that matter. They are still present in the returned data, so plotting modules can use them. Set col.visibility = TRUE if users should be able to bring them back; otherwise they stay hidden. Names that do not occur in data are ignored with a warning. Defaults to NULL (show every column).

filter.max.options

Integer. The maximum number of options a factor column's filter dropdown renders at once. Typing in the box narrows the list, so a low cap keeps high-cardinality columns usable. Defaults to 50.

Value

A reactive expression that evaluates to the filtered subset of data based on the current DT selection/filter state. All columns are retained, including any hidden via hide.columns. Pass this reactive to a plotting module's data argument to keep the plot in sync with the table filters.

See also

dataFilterUI(), resolve_column_targets()

Author

Jacob Martin

Examples

library(shiny)
library(VizModules)

ui <- fluidPage(
    dataFilterUI("filter"),
    verbatimTextOutput("rows")
)

server <- function(input, output, session) {
    data <- reactive(iris)
    # Petal columns are hidden on load, but the "Columns" button lets users
    # bring them back, and they remain in the returned data either way.
    filtered <- dataFilterServer("filter", data,
        factor.char.cols = TRUE,
        hide.columns = c("Petal.Length", "Petal.Width"),
        col.visibility = TRUE
    )
    output$rows <- renderPrint(nrow(filtered()))
}

if (interactive()) shinyApp(ui, server)