Filter on Select

Intercept file selection and apply custom filters before files are added to the queue.

What you should see: a rule the built-in validators do not cover, applied in onSelect: files are inspected and can be dropped before they ever reach the queue.

var uploader = CoreUpload.create('#filter-uploader', {
 uploadUrl: '/api/upload/upload',
 multiple: true,
 autoUpload: true,
 // onSelect receives the WHOLE selection; the array you return replaces it.
 onSelect: function(files) {
 return files.filter(function (file) {
 // Reject files larger than 5MB
 if (file.size > 5 * 1024 * 1024) {
 alert(file.name + ' is too large (max 5MB)');
 return false; // prevent file from being added
 }
 // Reject non-image files
 if (!/\.(jpg|jpeg|png|gif)$/i.test(file.name)) {
 alert(file.name + ' is not an image');
 return false;
 }
 return true; // accept the file
 });
 }
});