Build a Complex Popup for a Leaflet Map

Group a dataframe together by latitude/longitude columns and create a HTML popup with user-defined columns. By default, the unique values of character columns are collapsed into comma-separated lists, numeric columns are averaged, and date columns are presented as a range. This function returns the input dataframe appended with a "popup" column, which can then be used in the popup argument of a function like polarMap().

Usage

buildPopup(
  data,
  columns,
  latitude = NULL,
  longitude = NULL,
  type = NULL,
  fun.character = function(x) paste(unique(x), collapse = ", "),
  fun.numeric = function(x) signif(mean(x, na.rm = TRUE), 3),
  fun.dttm = function(x) paste(lubridate::floor_date(range(x, na.rm = TRUE), "day"),
    collapse = " to "),
  ...
)

Arguments

data

Input data table with geo-spatial information.

required

A data frame containing latitude and longitude information that will go on to be used in a function such as polarMap().

columns

A character vector of column names to include in the popup.

required

Summaries of the selected columns will appear in the popup. If a named vector is provided, the names of the vector will be used in place of the raw column names. See the Examples for more information.

latitude, longitude

The decimal latitude(Y)/longitude(X).

default: NULL | scope: dynamic & static

Column names representing the decimal latitude and longitude (or other Y/X coordinate if using a different crs). If not provided, will be automatically inferred from data by looking for a column named "lat"/"latitude" or "lon"/"lng"/"long"/"longitude" (case-insensitively).

type

A column to be passed to the type argument of another function.

default: NULL

Column which will be used for the type argument of other mapping functions. This only needs to be used if type is going to be used in polarMap() or another similar function, and you'd expect different values for the different map layers (for example, if you are calculating a mean pollutant concentration).

fun.character

A function to summarise character and factor columns.

default: function(x) paste(unique(x), collapse = ", ")

The default collapses unique values into a comma-separated list.

fun.numeric

A function to summarise numeric columns.

default: function(x) signif(mean(x, na.rm = TRUE), 3)

The default takes the mean to three significant figures. Other numeric summaries may be of interest, such as the maximum, minimum, standard deviation, and so on.

fun.dttm

A function to summarise date columns.

default: function(x) paste(lubridate::floor_date(range(x, na.rm = TRUE), "day"), collapse = " to ")

The default presents the date as a range. Other statistics of interest could be the start or end of the dates.

...

Not currently used.

Value

a tibble

Examples

if (FALSE) { # \dontrun{
buildPopup(
  data = polar_data,
  columns = c(
    "Site" = "site",
    "Site Type" = "site_type",
    "Date Range" = "date"
  )
) %>%
  polarMap("nox", popup = "popup")
} # }