Reputation: 12663
in my current project I used a AsyncFileUpload control from AJAX Control Toolkits. After I got the async file upload part working, I needed to filter the file type so users can only upload image files. I found the following code off web and it worked well:
function uploadStarted(sender, args) {
var filename = args.get_fileName();
var filext = filename.substring(filename.lastIndexOf(".") + 1);
if (filext == "jpg" || filext == "jpeg" || filext == "gif" || filext == "bmp") {
return true;
}
else
{
// force uploading cancel
args.set_cancel(true);
// set reason of cancel
args.set_errorMessage("Invalid File Format Selected");
return false;
}
}
The problem is : I don't understand this javascript. What is the type of args parameter? Where are the methods such as "get_fileName()", "set_cancel()" defined? I went to the homepage of the AsyncFileUpload control but couldn't find any documentation regarding the "args".
Can someone help me out explaining this Javascript? Thanks
Upvotes: 3
Views: 2593
Reputation: 12663
I think I can answer my own question
The first parameter identifies the object that fired the event, while the second provides information on the file being uploaded. In fact, it contains five useful properties accessed using the get_abc() syntax demonstrated above.
For more details refer to this article:
http://p2p.wrox.com/content/blogs/danm/enter-asyncfileupload-control
Upvotes: 2