#' Helper functions for using DT in Shiny
#'
#' These two functions are like most \code{fooOutput()} and \code{renderFoo()}
#' functions in the \pkg{shiny} package. The former is used to create a
#' container for table, and the latter is used in the server logic to render the
#' table.
#' @inheritParams shiny::dataTableOutput
#' @param width the width of the table container
#' @param height the height of the table container
#' @references \url{http://rstudio.github.io/DT/shiny.html}
#' @export
#' @examples # !formatR
#' if (interactive()) {
#' library(shiny)
#' shinyApp(
#' ui = fluidPage(fluidRow(column(12, DT::dataTableOutput('tbl')))),
#' server = function(input, output) {
#' output$tbl = DT::renderDataTable(
#' iris, options = list(lengthChange = FALSE)
#' )
#' }
#' )
#' }
dataTableOutput = function(outputId, width = '100%', height = 'auto') {
htmltools::attachDependencies(
htmlwidgets::shinyWidgetOutput(
outputId, 'datatables', width, height, package = 'DT'
),
crosstalk::crosstalkLibs(),
append = TRUE
)
}
#' @export
#' @rdname dataTableOutput
#' @inheritParams shiny::renderDataTable
#' @param expr an expression to create a table widget (normally via
#' \code{\link{datatable}()}), or a data object to be passed to
#' \code{datatable()} to create a table widget
#' @param server whether to use server-side processing. If \code{TRUE}, then the
#' data is kept on the server and the browser requests a page at a time; if
#' \code{FALSE}, then the entire data frame is sent to the browser at once.
#' Highly recommended for medium to large data frames, which can cause
#' browsers to slow down or crash.
#' @param ... ignored when \code{expr} returns a table widget, and passed as
#' additional arguments to \code{datatable()} when \code{expr} returns a data
#' object
renderDataTable = function(expr, server = TRUE, env = parent.frame(), quoted = FALSE, ...) {
if (!quoted) expr = substitute(expr)
# TODO: this can be simplified after this htmlwidgets PR is merged
# https://github.com/ramnathv/htmlwidgets/pull/122
currentSession = NULL
currentOutputName = NULL
exprFunc = shiny::exprToFunction(expr, env, quoted = TRUE)
widgetFunc = function() {
instance = exprFunc()
if (!all(c('datatables', 'htmlwidget') %in% class(instance))) {
instance = datatable(instance, ...)
} else if (length(list(...)) != 0) {
warning("renderDataTable ignores ... arguments when expr yields a datatable object; see ?renderDataTable")
}
# in the server mode, we should not store the full data in JSON
if (server && !is.null(instance[['x']])) {
if (!is.null(instance$x$options$crosstalkOptions$group)) {
stop("Crosstalk only works with DT client mode: DT::renderDataTable({...}, server=FALSE)")
}
origData = instance[['x']][['data']]
instance$x$data = NULL
# register the data object in a shiny session
options = instance[['x']][['options']]
# Normalize "ajax" argument; if we leave it a string then we have several
# code paths that need to account for both string and list representations
if (is.character(options[['ajax']])) {
options$ajax = list(url = options$ajax)
}
if (is.null(options[['ajax']][['url']])) {
url = sessionDataURL(currentSession, origData, currentOutputName, dataTablesFilter)
options$ajax$url = url
}
instance$x$options = fixServerOptions(options)
}
instance
}
renderFunc = htmlwidgets::shinyRenderWidget(
widgetFunc(), dataTableOutput, environment(), FALSE
)
func = shiny::markRenderFunction(dataTableOutput, function(shinysession, name, ...) {
currentSession <<- shinysession
currentOutputName <<- name
on.exit({
currentSession <<- NULL
currentOutputName <<- NULL
}, add = TRUE)
renderFunc()
})
# This snapshotPreprocess function was added in shiny 1.0.3.9001
if (exists("snapshotPreprocess", asNamespace("shiny"))) {
func = shiny::snapshotPreprocess(func, function(value) {
# Looks for a string like this in the JSON:
# "url":"session/2a2b834d90637a7559f3ebaba460ad10/dataobj/table?w=&nonce=aea032f33aedfd0e",
# and removes it, so that the value isn't saved in test snapshots.
gsub('"ajax"\\s*:\\s*\\{\\s*"url"\\s*:\\s*"[^"]*"\\s*,?', '"ajax":{', value)
})
}
func
}
#' Manipulate an existing DataTables instance in a Shiny app
#'
#' The function \code{datatableProxy()} creates a proxy object that can be used
#' to manipulate an existing DataTables instance in a Shiny app, e.g. select
#' rows/columns, or add rows.
#' @param outputId the id of the table to be manipulated (the same id as the one
#' you used in \code{\link{dataTableOutput}()})
#' @param session the Shiny session object (from the server function of the
#' Shiny app)
#' @param deferUntilFlush whether an action should be carried out right away, or
#' should be held until after the next time all of the outputs are updated
#' @note \code{addRow()} only works for client-side tables. If you want to use
#' it in a Shiny app, make sure to use \code{renderDataTable(..., server =
#' FALSE)}.
#' @references \url{http://rstudio.github.io/DT/shiny.html}
#' @rdname proxy
#' @export
dataTableProxy = function(
outputId, session = shiny::getDefaultReactiveDomain(), deferUntilFlush = TRUE
) {
if (is.null(session))
stop('datatableProxy() must be called from the server function of a Shiny app')
structure(
list(id = session$ns(outputId), session = session, deferUntilFlush = deferUntilFlush),
class = 'datatableProxy'
)
}
#' @param proxy a proxy object returned by \code{dataTableProxy()}
#' @param selected an integer vector of row/column indices, or a matrix of two
#' columns (row and column indices, respectively) for cell indices; you may
#' use \code{NULL} to clear existing selections
#' @rdname proxy
#' @export
selectRows = function(proxy, selected) {
invokeRemote(proxy, 'selectRows', list(I(selected)))
}
#' @rdname proxy
#' @export
selectColumns = function(proxy, selected) {
invokeRemote(proxy, 'selectColumns', list(I(selected)))
}
#' @rdname proxy
#' @export
selectCells = function(proxy, selected) {
invokeRemote(proxy, 'selectCells', list(selected))
}
#' @param data a single row of data to be added to the table; it can be a matrix
#' or data frame of one row, or a vector or list of row data (in the latter
#' case, please be cautious about the row name: if your table contains row
#' names, here \code{data} must also contain the row name as the first
#' element)
#' @rdname proxy
#' @export
addRow = function(proxy, data) {
if ((is.matrix(data) || is.data.frame(data)) && nrow(data) != 1)
stop("'data' must be of only one row")
invokeRemote(proxy, 'addRow', list(as.list(unname(data)), I(rownames(data))))
}
#' @rdname proxy
#' @export
clearSearch = function(proxy) {
updateSearch(proxy, list(global = '', columns = ''))
}
#' @param page a number indicating the page to select
#' @rdname proxy
#' @export
selectPage = function(proxy, page) {
invokeRemote(proxy, 'selectPage', list(page))
}
#' @param caption a new table caption (see the \code{caption} argument of
#' \code{\link{datatable}()})
#' @rdname proxy
#' @export
updateCaption = function(proxy, caption) {
invokeRemote(proxy, 'updateCaption', list(captionString(caption)))
}
#' @param keywords a list of two components: \code{global} is the global search
#' keyword of a single character string (ignored if \code{NULL});
#' \code{columns} is a character vector of the search keywords for all columns
#' (when the table has one column for the row names, this vector of keywords
#' should contain one keyword for the row names as well)
#' @rdname proxy
#' @export
updateSearch = function(proxy, keywords = list(global = NULL, columns = NULL)) {
global = keywords$global
if (is.null(global)) {
keywords['global'] = list(NULL)
} else {
if (!is.character(global) || length(global) != 1)
stop('keywords$global must be a character string')
}
columns = keywords$columns
if (is.null(columns)) {
keywords['columns'] = list(NULL)
} else {
if (is.character(columns)) {
if (length(columns) == 0) stop(
'The length of keywords$columns must be greater than zero if it is a character vector'
)
} else if (is.list(columns)) {
if (any(sapply(columns, length) > 1)) stop(
'keywords$columns should be a list of NULL or character strings'
)
} else stop('keywords$columns must be either a character vector or a list')
}
invokeRemote(proxy, 'updateSearch', list(keywords))
}
#' @param resetPaging whether to reset the paging position
#' @param clearSelection which existing selections to clear: it can be any
#' combinations of \code{row}, \code{column}, and \code{cell}, or \code{all}
#' for all three, or \code{none} to keep current selections (by default, all
#' selections are cleared after the data is reloaded)
#' @note \code{reloadData()} only works for tables in the server-side processing
#' mode, e.g. tables rendered with \code{renderDataTable(server = TRUE)}. The
#' data to be reloaded (i.e. the one you pass to \code{dataTableAjax()}) must
#' have exactly the same number of columns as the previous data object in the
#' table.
#' @rdname proxy
#' @export
reloadData = function(
proxy, resetPaging = TRUE, clearSelection = c('all', 'none', 'row', 'column', 'cell')
) {
if ('all' %in% clearSelection) clearSelection = c('row', 'column', 'cell')
invokeRemote(proxy, 'reloadData', list(resetPaging, clearSelection))
}
#' Replace data in an existing table
#'
#' Replace the data object of a table output and avoid regenerating the full
#' table, in which case the state of the current table will be preserved
#' (sorting, filtering, and pagination) and applied to the table with new data.
#' @param proxy a proxy object created by \code{dataTableProxy()}
#' @param data the new data object to be loaded in the table
#' @param ... other arguments to be passed to \code{\link{dataTableAjax}()}
#' @param resetPaging,clearSelection passed to \code{\link{reloadData}()}
#' @note When you replace the data in an existing table, please make sure the
#' new data has the same number of columns as the current data. When you have
#' enabled column filters, you should also make sure the attributes of every
#' column remain the same, e.g. factor columns should have the same or fewer
#' levels, and numeric columns should have the same or smaller range,
#' otherwise the filters may never be able to reach certain rows in the data.
#' @export
replaceData = function(proxy, data, ..., resetPaging = TRUE, clearSelection = 'all') {
dataTableAjax(proxy$session, data, ..., outputId = proxy$id)
reloadData(proxy, resetPaging, clearSelection)
}
invokeRemote = function(proxy, method, args = list()) {
if (!inherits(proxy, 'datatableProxy'))
stop('Invalid proxy argument; table proxy object was expected')
msg = list(id = proxy$id, call = list(method = method, args = args))
sess = proxy$session
if (proxy$deferUntilFlush) {
sess$onFlushed(function() {
sess$sendCustomMessage('datatable-calls', msg)
}, once = TRUE)
} else {
sess$sendCustomMessage('datatable-calls', msg)
}
proxy
}
shinyFun = function(name) getFromNamespace(name, 'shiny')
#' Register a data object in a shiny session for DataTables
#'
#' This function stores a data object in a shiny session and returns a URL that
#' returns JSON data based on DataTables Ajax requests. The URL can be used as
#' the \code{url} option inside the \code{ajax} option of the table. It is
#' basically an implementation of server-side processing of DataTables in R.
#' Filtering, sorting, and pagination are processed through R instead of
#' JavaScript (client-side processing).
#'
#' Normally you should not need to call this function directly. It is called
#' internally when a table widget is rendered in a Shiny app to configure the
#' table option \code{ajax} automatically. If you are familiar with
#' \pkg{DataTables}' server-side processing, and want to use a custom filter
#' function, you may call this function to get an Ajax URL.
#' @param session the \code{session} object in the shiny server function
#' (\code{function(input, output, session)})
#' @param data a data object (will be coerced to a data frame internally)
#' @param rownames see \code{\link{datatable}()}; it must be consistent with
#' what you use in \code{datatable()}, e.g. if the widget is generated by
#' \code{datatable(rownames = FALSE)}, you must also use
#' \code{dataTableAjax(rownames = FALSE)} here
#' @param filter (for expert use only) a function with two arguments \code{data}
#' and \code{params} (Ajax parameters, a list of the form \code{list(search =
#' list(value = 'FOO', regex = 'false'), length = 10, ...)}) that return the
#' filtered table result according to the DataTables Ajax request
#' @param outputId the output ID of the table (the same ID passed to
#' \code{dataTableOutput()}; if missing, a random string)
#' @references \url{http://rstudio.github.io/DT/server.html}
#' @return A character string (an Ajax URL that can be queried by DataTables).
#' @example inst/examples/ajax-shiny.R
#' @export
dataTableAjax = function(session, data, rownames, filter = dataTablesFilter, outputId) {
oop = options(stringsAsFactors = FALSE); on.exit(options(oop), add = TRUE)
# abuse tempfile() to obtain a random id unique to this R session
if (missing(outputId)) outputId = basename(tempfile(''))
# deal with row names: rownames = TRUE or missing, use rownames(data)
rn = if (missing(rownames) || isTRUE(rownames)) base::rownames(data) else {
if (is.character(rownames)) rownames # use custom row names
}
data = as.data.frame(data) # think dplyr
if (length(rn)) data = cbind(' ' = rn, data)
sessionDataURL(session, data, outputId, filter)
}
sessionDataURL = function(session, data, id, filter) {
URLdecode = shinyFun('URLdecode')
toJSON = shinyFun('toJSON')
httpResponse = shinyFun('httpResponse')
filterFun = function(data, req) {
# DataTables requests were sent via POST
params = URLdecode(rawToChar(req$rook.input$read()))
Encoding(params) = 'UTF-8'
# use system native encoding if possible (again, this grep(fixed = TRUE) bug
# https://bugs.r-project.org/bugzilla3/show_bug.cgi?id=16264)
params2 = iconv(params, 'UTF-8', '')
if (!is.na(params2)) params = params2 else warning(
'Some DataTables parameters contain multibyte characters ',
'that do not work in current locale.'
)
params = shiny::parseQueryString(params, nested = TRUE)
res = tryCatch(filter(data, params), error = function(e) {
list(error = as.character(e))
})
httpResponse(200, 'application/json', enc2utf8(toJSON(res, dataframe = 'rows')))
}
session$registerDataObj(id, data, filterFun)
}
# filter a data frame according to the DataTables request parameters
dataTablesFilter = function(data, params) {
n = nrow(data)
q = params
ci = q$search[['caseInsensitive']] == 'true'
# users may be updating the table too frequently
if (length(q$columns) != ncol(data)) return(list(
draw = as.integer(q$draw),
recordsTotal = n,
recordsFiltered = 0,
data = list(),
DT_rows_all = seq_len(n),
DT_rows_current = list()
))
# global searching
i = logical(n)
# for some reason, q$search might be NULL, leading to error `if (logical(0))`
if (isTRUE(q$search[['value']] != '')) for (j in seq_len(ncol(data))) {
if (q$columns[[j]][['searchable']] != 'true') next
i0 = grep2(
q$search[['value']], as.character(data[, j]),
fixed = q$search[['regex']] == 'false', ignore.case = ci
)
i[i0] = TRUE
} else i = !i
i = which(i)
# search by columns
if (length(i)) for (j in names(q$columns)) {
col = q$columns[[j]]
# if the j-th column is not searchable or the search string is "", skip it
if (col[['searchable']] != 'true') next
if ((k <- col[['search']][['value']]) == '') next
j = as.integer(j)
dj = data[, j + 1]
ij = if (is.numeric(dj) || is.Date(dj)) {
which(filterRange(dj, k))
} else if (is.factor(dj)) {
which(dj %in% jsonlite::fromJSON(k))
} else if (is.logical(dj)) {
which(dj %in% as.logical(jsonlite::fromJSON(k)))
} else {
grep2(k, as.character(dj), fixed = col[['search']][['regex']] == 'false',
ignore.case = ci)
}
i = intersect(ij, i)
if (length(i) == 0) break
}
if (length(i) != n) data = data[i, , drop = FALSE]
iAll = i # row indices of filtered data
# sorting
oList = list()
for (ord in q$order) {
k = ord[['column']] # which column to sort
d = ord[['dir']] # direction asc/desc
if (q$columns[[k]][['orderable']] != 'true') next
col = data[, as.integer(k) + 1]
oList[[length(oList) + 1]] = (if (d == 'asc') identity else `-`)(
if (is.numeric(col)) col else xtfrm(col)
)
}
if (length(oList)) {
i = do.call(order, oList)
data = data[i, , drop = FALSE]
iAll = iAll[i]
}
# paging
if (q$length != '-1') {
len = as.integer(q$length)
# I don't know why this can happen, but see https://github.com/rstudio/DT/issues/164
if (is.na(len)) {
warning("The DataTables parameter 'length' is '", q$length, "' (invalid).")
len = 0
}
i = seq(as.integer(q$start) + 1L, length.out = len)
i = i[i <= nrow(data)]
fdata = data[i, , drop = FALSE] # filtered data
iCurrent = iAll[i]
} else {
fdata = data
iCurrent = iAll
}
if (q$escape != 'false') {
k = seq_len(ncol(fdata))
if (q$escape != 'true') {
# q$escape might be negative indices, e.g. c(-1, -5)
k = k[as.integer(strsplit(q$escape, ',')[[1]])]
}
for (j in k) if (maybe_character(fdata[, j])) fdata[, j] = htmlEscape(fdata[, j])
}
# TODO: if iAll is just 1:n, is it necessary to pass this vector to JSON, then
# to R? When n is large, it may not be very efficient
list(
draw = as.integer(q$draw),
recordsTotal = n,
recordsFiltered = nrow(data),
data = cleanDataFrame(fdata),
DT_rows_all = iAll,
DT_rows_current = iCurrent
)
}
# when both ignore.case and fixed are TRUE, we use grep(ignore.case = FALSE,
# fixed = TRUE) to do lower-case matching of pattern on x
grep2 = function(pattern, x, ignore.case = FALSE, fixed = FALSE, ...) {
if (fixed && ignore.case) {
pattern = tolower(pattern)
x = tolower(x)
ignore.case = FALSE
}
# when the user types in the search box, the regular expression may not be
# complete before it is sent to the server, in which case we do not search
if (!fixed && inherits(try(grep(pattern, ''), silent = TRUE), 'try-error'))
return(seq_along(x))
grep(pattern, x, ignore.case = ignore.case, fixed = fixed, ...)
}
# filter a numeric/date/time vector using the search string "lower ... upper"
filterRange = function(d, string) {
if (!grepl('[.]{3}', string) || length(r <- strsplit(string, '[.]{3}')[[1]]) > 2)
stop('The range of a numeric / date / time column must be of length 2')
if (length(r) == 1) r = c(r, '') # lower,
r = gsub('^\\s+|\\s+$', '', r)
r1 = r[1]; r2 = r[2]
if (is.numeric(d)) {
r1 = as.numeric(r1); r2 = as.numeric(r2)
} else if (inherits(d, 'Date')) {
if (r1 != '') r1 = as.Date(r1)
if (r2 != '') r2 = as.Date(r2)
} else {
if (r1 != '') r1 = as.POSIXct(r1, tz = 'GMT', '%Y-%m-%dT%H:%M:%S')
if (r2 != '') r2 = as.POSIXct(r2, tz = 'GMT', '%Y-%m-%dT%H:%M:%S')
}
if (r[1] == '') return(d <= r2)
if (r[2] == '') return(d >= r1)
d >= r1 & d <= r2
}
# treat factors as characters
maybe_character = function(x) {
is.character(x) || is.factor(x)
}
# make sure we have a tidy data frame (no unusual structures in it)
cleanDataFrame = function(x) {
x = unname(x) # remove column names
if (!is.data.frame(x)) return(x)
for (j in seq_len(ncol(x))) {
xj = x[, j]
xj = unname(xj) # remove names
dim(xj) = NULL # drop dimensions
if (is.table(xj)) xj = c(xj) # drop the table class
x[, j] = xj
}
unname(x)
}
fixServerOptions = function(options) {
options$serverSide = TRUE
if (is.null(options$processing)) options$processing = TRUE
# if you generated the Ajax URL from dataTableAjax(), I'll configure type:
# 'POST' and a few other options automatically
if (!inShiny()) return(options)
if (length(grep('^session/[a-z0-9]+/dataobj/', options$ajax$url)) == 0)
return(options)
if (is.null(options$ajax$type)) options$ajax$type = 'POST'
if (is.null(options$ajax$data)) options$ajax$data = JS(
'function(d) {',
sprintf(
'd.search.caseInsensitive = %s;',
tolower(!isFALSE(options[['search']]$caseInsensitive))
),
sprintf('d.escape = %s;', attr(options, 'escapeIdx', exact = TRUE)),
'var encodeAmp = function(x) { x.value = x.value.replace(/&/g, "%26"); }',
'encodeAmp(d.search);',
'$.each(d.columns, function(i, v) {encodeAmp(v.search);});',
'}'
)
options
}
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