Solved

Problems with function literal used as DWR callback.

Posted on 2007-12-03
4
952 Views
Last Modified: 2008-02-27
I have written a piece of code to be executed on form submit. The code consists of a containing object called EventHandler which handles both initialisation and execution of event handlers.

I use prototype for the eventhandling code. The problem is that the property error of type StringBuffer (another object) does not play well with the function literal myCallback (which is invoked by DWR).

I want to store all validation errors in the error property for access later but neither of the two versions I have attached the code to does the trick for me. I am guessing it has to do with the scope in JavaScript but I can't pinpoint the problem.

Any help greatly appreciated!
//
//Invoked by
//
Event.observe(matchPlayerFormId, 'submit', this.formSubmit.bind(this));
 
//
//Version 1
//
EventHandler.prototype.formSubmit = function(event) {
	this.error = new StringBuffer();
 
	var myCallback = function(data){
		console.log("in callback, result = '" + data + "'");
		if (data.length > 0) {
			this.error.append(data);
			console.log("Intermediate: " + error.toString());
		}
	};
 
	for (var i = 0; i < this.validationNodes.length; i++){
		var variableId = this.validationNodes[i].id;
			
		var variableName = this.validationNodes[i].name;
	
		var variableValue = document.getElementById(variableId).value;
		
		JMatchValidator.validate(variableName, variableValue, myCallback.bind(this));
 
	}
		
	if (this.error.length() > 0){
		console.log("Submit cancelled");
		Event.stop(event);
		
	}
}
 
//
//Version 2
//
EventHandler.prototype.formSubmit = function(event) {
	var error = new StringBuffer();
 
	var myCallback = function(data){
		if (data.length > 0) {
			error.append(data);
		}
	};
 
	alert("Start submit");
	for (var i = 0; i < this.validationNodes.length; i++){
		var variableId = this.validationNodes[i].id;
			
		var variableName = this.validationNodes[i].name;
	
		var variableValue = document.getElementById(variableId).value;
 
		JMatchValidator.validate(variableName, variableValue, myCallback.bind(this));
 
	}
		
	if (error.length() > 0){
		console.log("Submit cancelled");
		Event.stop(event);
		
	}
}

Open in new window

0
Comment
Question by:kveasana
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
4 Comments
 
LVL 29

Accepted Solution

by:
Badotz earned 500 total points
ID: 20524057
// Try this:
//
var self = this;
JMatchValidator.validate(variableName, variableValue, myCallback.bind(this, self));

// I have noticed that "bind" drops the first object from the argument list
// The first object bwcomes the object that is "called"
0
 
LVL 1

Expert Comment

by:Computer101
ID: 20999905
Forced accept.

Computer101
EE Admin
0

Featured Post

The Ultimate Checklist to Optimize Your Website

Websites are getting bigger and complicated by the day. Video, images, custom fonts are all great for showcasing your product/service. But the price to pay in terms of reduced page load times and ultimately, decreased sales, can lead to some difficult decisions about what to cut.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

International Data Corporation (IDC) prognosticates that before the current the year gets over disbursing on IT framework products to be sent in cloud environs will be $37.1B.
It’s a strangely common occurrence that when you send someone their login details for a system, they can’t get in. This article will help you understand why it happens, and what you can do about it.
This video teaches viewers how to create their own website using cPanel and Wordpress. Tutorial walks users through how to set up their own domain name from tools like Domain Registrar, Hosting Account, and Wordpress. More specifically, the order in…
The viewer will learn how to dynamically set the form action using jQuery.

690 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question