Reactive file reader
Given a file path and read function, returns a reactive data source for the contents of the file.
reactiveFileReader(intervalMillis, session, filePath, readFunc, ...)
intervalMillis |
Approximate number of milliseconds to wait between checks of the file's last modified time. This can be a numeric value, or a function that returns a numeric value. |
session |
The user session to associate this file reader with, or
|
filePath |
The file path to poll against and to pass to |
readFunc |
The function to use to read the file; must expect the first argument to be the file path to read. The return value of this function is used as the value of the reactive file reader. |
... |
Any additional arguments to pass to |
reactiveFileReader works by periodically checking the file's last
modified time; if it has changed, then the file is re-read and any reactive
dependents are invalidated.
The intervalMillis, filePath, and readFunc functions
will each be executed in a reactive context; therefore, they may read
reactive values and reactive expressions.
A reactive expression that returns the contents of the file, and automatically invalidates when the file changes on disk (as determined by last modified time).
## Not run:
# Per-session reactive file reader
function(input, output, session) {
fileData <- reactiveFileReader(1000, session, 'data.csv', read.csv)
output$data <- renderTable({
fileData()
})
}
# Cross-session reactive file reader. In this example, all sessions share
# the same reader, so read.csv only gets executed once no matter how many
# user sessions are connected.
fileData <- reactiveFileReader(1000, NULL, 'data.csv', read.csv)
function(input, output, session) {
output$data <- renderTable({
fileData()
})
}
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.