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Updating a web document using ajax

I have a web application where users amend a document on the web. There is lots of information to be captured and this information needs to be on one screen for ease of use. We have a problem where users say their browsers crash and their information is lost. We want to implement autosave using ajax on our form. I am a novice at Ajax and from what I have read, we use the ajax code to submit the request to the server. This I have working. BUT

The listening mechanism I have for the request is an agent. So basically, when I send the request I specify the url to the agent and I include the doc id , the field name and the field value in the queryString.
The problem I am concerned about it that the agent will go and find the backend document make the change to the field and save the document. But the user is still busy editing the document and when they save the document, it sends a proper save to the server. Will this cause a save conflict on the document when the user saves the document as we have saved the document in the backend and now those same fields are sent back to the server ?

Is there another approach to implementing autosave over the web ?
Is there another listening mechanism in domino other than an agent to sort out the update to the field ?

var xmlHttp;
function createXMLHttpRequest() { 
  if (window.ActiveXObject) { 
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); 
  }
  else if (window.XMLHttpRequest) { 
    xmlHttp = new XMLHttpRequest(); 
  }
}
 
 
 
 
function AutoSave()
{
var CurrLocation = new String (window.location)
var LocationSplit = CurrLocation.split("/")
var server = LocationSplit[0] +"//" + LocationSplit[2] 
var path = document.forms[0].dbpath.value
 
var pos=0;
 
currURL = (document.location.href).toLowerCase();
 
if (trim(server) == "") {
pos = currURL.indexOf('://'); 
if (pos < 0 )
{
	var CurrLocation = new String (window.location)
	var LocationSplit = CurrLocation.split("/")
	var server = LocationSplit[0] +"//" + LocationSplit[2] 
}
//server = "http://Localhost" // PUT YOUR SERVERNAME HERE
else
{
pos += 3;
pos = currURL.indexOf('/', pos);
server = currURL.substring(0, pos)
}
}
 
if( trim(path) == "" )
{
if( pos > 0 )
{
newPos = currURL.indexOf('.nsf',pos);
if (newPos > 0)
{
path = currURL.substring(pos+1,newPos+4)
}
}
}
 
//Javascript index starts at 0, so need to decrement the column by -1
var args='&docID=' + document.forms[0].DocID.value + "&testing=" + document.forms[0].Testing.value
vurl = trim(server)+"/"+trim(path)+"/UpdateMyDocument?openagent" + args
alert(vurl)
 
  createXMLHttpRequest(); // build update string
  alert("1")
  //xmlHttp.onreadystatechange = this.handleStateChange;
  alert("2")
  xmlHttp.open("GET" ,vurl ,true);
  alert("3")
  xmlHttp.send(null);
  alert("4")
	//UpdateMyDocument
 
}
 
 
 
function trim(sStr)
{
var iI = 0;
var iJ = 0;
var iTam = 0;
var sAux = "";
 
iTam = sStr.length;
if(iTam==0) return(sStr);
 
for(iI=0; iI<iTam; iI++)
if(sStr.charAt(iI)!=' ') break;
 
if(iI >= iTam) return("");
 
for(iJ=iTam - 1; iJ>=0; iJ--)
if(sStr.charAt(iJ)!=' ') break;
 
return(sStr.substring(iI,iJ+1));
} //End of trim

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ASKER CERTIFIED SOLUTION

Sjef Bosman

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quzzie

I'm not a fan of AJAX. it tends to add significant complexity to a problem that can usually be solved without it.

If the fundamental problem is that the users are filling in a really big form that sometimes crashes and they lose data cos the form is so big it takes too long to complete, then one solution would be to break the form down.

you often see on web sites (such as shopping carts, questionaires, surveys) the form split in to sections. As you progress from section to section you save the document. you could either split the notes back end document up into smaller chunks, or as SJEF suggests, just do a filesave after each section

devguru001

ASKER

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