R.rsp (version 0.40.0)

HttpDaemon: The HttpDaemon class

Description

Package: R.rsp Class HttpDaemon

Object ~~| ~~+--HttpDaemon

Directly known subclasses:

public static class HttpDaemon extends Object

A minimalistic HTTP daemon (web server) that also preprocesses RSP.

Usage

HttpDaemon(...)

Arguments

...

Not used.

Fields and Methods

Methods:

	appendRootPaths
Appends and inserts new paths to the list of known root directories.
as.character	Returns a short string describing the HTTP daemon.
	finalize
-
getConfig	Retrieves the server's 'config' structure from Tcl.
	getCount
-
getDefaultFilenamePattern	Gets the default filename pattern to be loaded by the HTTP daemon.
	getHttpRequest
Gets the HTTP request.
getPort	Gets the socket port of the HTTP daemon.
	getRootPaths
Gets the root directories of the HTTP daemon.
insertRootPaths	-
	isStarted
Checks if the HTTP daemon is started.
openUrl	Starts the HTTP daemon and launches the specified URL.
	processRsp
Processes an RSP page.
restart	Restarts the HTTP daemon.
	setCount
-
setRootPaths	Sets a new set of root directories for the HTTP daemon.
	sourceTcl
Loads the Tcl source for the HTTP daemon into R.
start	Starts the HTTP daemon.
	startHelp
Starts the HTTP daemon and launches the help page.
stop	Stops the HTTP daemon.
	writeResponse
Writes a string to the HTTP output connection.

Methods inherited from Object: $, $<-, [[, [[<-, as.character, attach, attachLocally, clearCache, clearLookupCache, clone, detach, equals, extend, finalize, getEnvironment, getFieldModifier, getFieldModifiers, getFields, getInstantiationTime, getStaticInstance, hasField, hashCode, ll, load, names, objectSize, print, save

Details

The actual server is written in Tcl such that it runs in a non-blocking mode, which means that the R prompt will be available for other things. This class is tightly coupled with the source code of the Tcl script.

For security reasons, the server only accept connections from the local host (127.0.0.1). This lowers the risk for external computers to gain access to the R session. This is asserted by the accept_connect Tcl procedure in r-httpd.tcl (located in system("tcl/", package="R.rsp")). If access from other hosts are wanted, then this procedure needs to be modified.

The Tcl server was written by Steve Uhlers, and later adopted for R by Philippe Grosjean and Tom Short (Rpad package author) [1].

References

[1] Rpad package, Tom Short, 2005.

Examples

if (interactive()) {
  if (!HttpDaemon$isStarted()) {
    # Start the web server
    rootPath <- system.file("rsp", package="R.rsp")
    HttpDaemon$start(rootPath=rootPath, port=8074, default="^index[.](html|.*)$")
  }
 
  browseURL("http://127.0.0.1:8074/")
}