Package 'crosstalk'

Description

This helper function makes it easy to put HTML elements side by side. It can be called directly from the console but is especially designed to work in an R Markdown document. Warning: This will bring in all of Bootstrap!

Usage

bscols(..., widths = NA, device = c("xs", "sm", "md", "lg"))

Arguments

Value

A browsable HTML element.

Examples

library(htmltools)

# If width is unspecified, equal widths will be used
bscols(
  div(style = css(width="100%", height="400px", background_color="red")),
  div(style = css(width="100%", height="400px", background_color="blue"))
)

# Use NA to absorb remaining width
bscols(widths = c(2, NA, NA),
  div(style = css(width="100%", height="400px", background_color="red")),
  div(style = css(width="100%", height="400px", background_color="blue")),
  div(style = css(width="100%", height="400px", background_color="green"))
)

# Recycling widths
bscols(widths = c(2, 4),
  div(style = css(width="100%", height="400px", background_color="red")),
  div(style = css(width="100%", height="400px", background_color="blue")),
  div(style = css(width="100%", height="400px", background_color="red")),
  div(style = css(width="100%", height="400px", background_color="blue"))
)

Description

An object that can be used in a Shiny server function to get or set a crosstalk variable that exists on the client. The client copy of the variable is the canonical copy, so there is no direct "set" method that immediately changes the value; instead, there is a 'sendUpdate' method that sends a request to the browser to change the value, which will then cause the new value to be relayed back to the server.

This object is used to implement SharedData and should not need to be used directly by users.

Methods

Public methods

• ClientValue$new()

• ClientValue$get()

• ClientValue$sendUpdate()

• ClientValue$clone()

Method new()

Creates a new ClientValue object to reflect the crosstalk variable specified by 'group' and 'name'.

Usage

ClientValue$new(
  name,
  group = "default",
  session = shiny::getDefaultReactiveDomain()
)

Arguments

Method get()

Read the value. This is a reactive operation akin to reading a reactive value, and so can only be done in a reactive context (e.g. in a 'shiny::reactive()', 'shiny::observe()', or 'shiny::isolate()' block).

Usage

ClientValue$get()

Method sendUpdate()

Send a message to the browser asking it to update the crosstalk var to the given value. This update does not happen synchronously, that is, a call to 'get()' immediately following 'sendUpdate(value)' will not reflect the new value.

Usage

ClientValue$sendUpdate(value)

Arguments

Method clone()

The objects of this class are cloneable with this method.

Usage

ClientValue$clone(deep = FALSE)

Arguments

Examples

library(shiny)

server <- function(input, output, session) {
  cv <- ClientValue$new("var1", "group1")

  r <- reactive({
    # Don't proceed unless cv$get() is a non-NULL value
    validate(need(cv$get(), message = FALSE))

    runif(cv$get())
  })

  observeEvent(input$click, {
    cv$sendUpdate(NULL)
  })
}

Description

List of htmlDependency objects necessary for Crosstalk to function. Intended for widget authors.

Usage

crosstalkLibs()

Description

Creates a select box or list of checkboxes, for filtering a SharedData object based on categorical data.

Usage

filter_select(id, label, sharedData, group, allLevels = FALSE, multiple = TRUE)

filter_checkbox(
  id,
  label,
  sharedData,
  group,
  allLevels = FALSE,
  inline = FALSE,
  columns = 1
)

Arguments

Examples

## Only run examples in interactive R sessions
if (interactive()) {

sd <- SharedData$new(chickwts)
filter_select("feedtype", "Feed type", sd, "feed")

}

Description

Creates a slider widget that lets users filter observations based on a range of values.

Usage

filter_slider(
  id,
  label,
  sharedData,
  column,
  step = NULL,
  round = FALSE,
  ticks = TRUE,
  animate = FALSE,
  width = NULL,
  sep = ",",
  pre = NULL,
  post = NULL,
  timeFormat = NULL,
  timezone = NULL,
  dragRange = TRUE,
  min = NULL,
  max = NULL
)

animation_options(
  interval = 1000,
  loop = FALSE,
  playButton = NULL,
  pauseButton = NULL
)

Arguments

Examples

## Only run examples in interactive R sessions
if (interactive()) {

sd <- SharedData$new(mtcars)
filter_slider("mpg", "Miles per gallon", sd, "mpg")

}

Description

Check if an object is an instance of SharedData or not.

Usage

is.SharedData(x)

Arguments

Value

logical

Description

Waits for a brush to change, and propagates that change to the sharedData object.

Usage

maintain_selection(sharedData, brushId, ownerId = "")

Arguments

Description

Add scale_fill_selection() or scale_color_selection to a ggplot to customize the scale for fill or color, respectively, for linked brushing. Use selection_factor to turn logical vectors representing selection, to a factor with the levels ordered for use with ggplot2 bar stacking.

Usage

scale_fill_selection(color_false, color_true)

scale_color_selection(color_false, color_true)

selection_factor(
  x,
  na.replace = c(FALSE, NA, TRUE),
  reverse = packageVersion("ggplot2") < "2.2.0"
)

Arguments

Examples

## Not run: 
sd <- SharedData$new(iris)
renderPlot({
  df <- sd$data(withSelection = TRUE, withFilter = TRUE)
  ggplot(df, aes(Sepal.Length, Sepal.Width,
    color = selection_factor(df))) +
    geom_point() +
    scale_color_selection("#444444", "skyblue1")
})


## End(Not run)

Description

An R6 class that represents a shared data frame, or sufficiently data frame-like object.

The primary use for SharedData is to be passed to Crosstalk-compatible widgets in place of a data frame. Each SharedData$new(...) call makes a new "group" of widgets that link to each other, but not to widgets in other groups. You can also use a SharedData object from Shiny code in order to react to filtering and brushing from non-widget visualizations (like ggplot2 plots).

Methods

Public methods

• SharedData$new()

• SharedData$origData()

• SharedData$groupName()

• SharedData$key()

• SharedData$data()

• SharedData$selection()

• SharedData$clearSelection()

• SharedData$clone()

Method new()

Usage

SharedData$new(
  data,
  key = NULL,
  group = createUniqueId(4, prefix = "SharedData")
)

Arguments

Method origData()

Return the data frame that was used to create this SharedData instance. If a reactive expression, evaluate the reactive expression. Equivalent to SharedData$data(FALSE, FALSE, FALSE).

Usage

SharedData$origData()

Method groupName()

Returns the value of group that was used to create this instance.

Usage

SharedData$groupName()

Method key()

Returns the vector of key values. Filtering is not applied.

Usage

SharedData$key()

Method data()

Return the data (or read and return the data if the data is a Shiny reactive expression).

When running in Shiny, calling data() is a reactive operation that will invalidate if the selection or filter change (assuming that information was requested), or if the original data is a reactive expression that has invalidated.

Usage

SharedData$data(withSelection = FALSE, withFilter = TRUE, withKey = FALSE)

Arguments

Method selection()

Get or set the current selection in the client.

If called without arguments, returns a logical vector of rows that are currently selected (brushed), or NULL if no selection exists. Intended to be called from a Shiny reactive context, and invalidates whenever the selection changes.

If called with one or two arguments, sets the selection based on the given value indirectly, by sending the value to the web browser (assumes an active Shiny app or Shiny R Markdown document).

Usage

SharedData$selection(value, ownerId = "")

Arguments

Method clearSelection()

Clears the selection indirectly, by sending an instruction to the client that it should do so.

Usage

SharedData$clearSelection(ownerId = "")

Arguments

Method clone()

The objects of this class are cloneable with this method.

Usage

SharedData$clone(deep = FALSE)

Arguments