Kendo UI File Uploading Client Side Validation

In Kendo UI async file uploading there is no option to make some client side validation like:

• No of files you can upload at a time
• Size of the file
• Extension of your uploading file

              So, how we can achieve this ? So, to know that see the javascript code snippet below. I am going to explain that.

$('#selectedFiles-edit-win').kendoUpload({

  multiple: true,

 localization: {

  select: 'Select File(s)'

 },

 async: {

  saveUrl: "/CFCS/AjaxFactory.cfc?method=uploadFile",

  removeUrl: "/CFCS/AjaxFactory.cfc?method=cancelUploadedFile",

  autoUpload: true

 },

select: function(e) {

 var files = e.files;

 if( files.length  > 10 ) {

  alert("Maximum 10 files can be uploaded at a time.");

  e.preventDefault();

  return false;

 }

 

 for(var fileCntr = 0; fileCntr < files.length; fileCntr ++) {

  if( files[fileCntr].size > 10485760 ) {

   alert("File size more than 10MB can not be uploaded.");

   e.preventDefault();

   return false;

  }

 

  if( files[fileCntr].extension.toLowerCase() == '.exe' ) {

   alert("Executable files can not be uploaded.");

   e.preventDefault();

   return false;

  }

 }

}

});

  So, if you notice in select method we are getting all selected files in "e.files". Using that we can get all information of the selected files .

              To cancel the selected files we are just writing the line "e.preventDefault();". After each e.preventDefault() I am writing "return false" that is because when the condition checking gets an error it just comes out of the function with one message. If we will remove that then it will alert all error messages then it will cancel the selected files.
          To display only first error message I have wrote "return false". If you want to display all error messages then you write your own javascript logic.

So, now you can see what other information "e.files" and according to that you can implement your logic.