HttpClientRequest (Class)

An HttpClientRequest object lets you perform certain operations as an HTTP client.

Exemple :

var req = new HttpClientRequest("http://www.somewhere.com/login")

var buffer = new MemoryBuffer()
buffer.fromString("MyLogin" + ':' + "MyPassword", "iso-8859-1")

req.header["Authorization"] = "Basic " + buffer.toBase64()
req.header["Content-Type"] = "text/xml; charset=utf-8"
req.method = "SEARCH"
req.body = "<xml>any content</xml>"

req.execute()
     

The object can be used in two different modes: standard or keep alive. Standard mode lets you send a single query, keep alive mode lets you send several queries while maintaining the connection open. The status of the object depends on the method use sequence. If the connect() method is called, the object switches to "keep alive" mode. Example

var req = new HttpClientRequest("http://evc-cit.info/cgi-bin/cit042/timeofday.cgi")

req.connect()
// Now the object is in keep-alive mode, we can sand many requests using
// the same connection

// Request ten times the time of the cgi
var i = 0
while ( i < 10 )
{
  req.execute()
  var response = req.reponse
  i++
}
req.disconnect()
   

Queries are executed in blocking mode by default, which means that the

execute

function only returns control once the query is sent and the response received. It is also possible to execute queries in asynchronous mode. In this case, the

execute

function returns control immediately, and a function will be called once the response is received. This enables the simultaneous execution of several queries. The following program is a full example that shows you how to run a series of HTTP uploads opening 3 connections at the same time, where each upload starts once the last one is finished.

var list = [
  "http://www.adobe.com/",
  "http://www.google.com/",
  "http://www.mozilla.org/",
  "http://www.linux.org/",
  "http://www.postgresql.org/"]

var requests = []

var complete = function(req, context, status)
{
  if( status == "success" )
    logInfo("Receiving " + context + ": " +  req.url + ": code = " + req.response.code)
  else
    logWarning("Error " + context + ": " + req.url + ": " + status)

  sendNext(context)
}

function sendNext(context)
{
  // Repeat until the first execute() passes
  while( list.length != 0 )
  {
    // Pick one URL from the list
    var url = list.shift()

    var req = new HttpClientRequest(url)
    req.complete = complete
    try
    {
      req.execute(false, true, context, 5000)
      logInfo("Sending " + url)
      requests.push(req)
      return
    }
    catch(e)
    {
      // Log a message and pick up next item from list
      logWarning("Failed to send " + url)
    }
  }
}

// Start 3 requests
sendNext(1)
sendNext(2)
sendNext(3)

// Wait until all requests are completed
HttpClientRequest.wait(requests)

logInfo("Finished.")
         

Available in:

• Content management
• Delivery properties
• Typology rule
• JSSP
• SOAP Method
• WebApp
• Workflow