How to limit the number of dropzone.js files uploa

Question

Depending on the use case, how do I constrain the number of files that dropzone.js will allow?

For example, I might need to only allow 1, 2, or 4 files uploaded.

It's not uploadMultiple. Unfortunately, uploadMultiple only applies to the number of files handled per request.

Answer 1

maxFiles: 1 does the job but if you also want to remove the additional files you can use this sample code taken from the Wiki page:

How can I limit the number of files?

You're in luck! Starting with 3.7.0 Dropzone supports the maxFiles option. Simply set it to the desired quantity and you're good to go. If you don't want the rejected files to be viewed, simply register for the maxfilesexceeded event, and remove the file immediately:

myDropzone.on("maxfilesexceeded", function(file)
{
    this.removeFile(file);
});

Answer 2

I thought that the most intuitive single file upload process was to replace the previous file upon a new entry.

  $(".drop-image").dropzone({
    url: '/cart?upload-engraving=true',
    maxFiles: 1,
    maxfilesexceeded: function(file) {
        this.removeAllFiles();
        this.addFile(file);
    }
})

Answer 3

You can also add in callbacks - here I'm using Dropzone for Angular

dzCallbacks = {
    'addedfile' : function(file){
        $scope.btSend = false;
        $scope.form.logoFile = file;
    },
    'success' : function(file, xhr){
        $scope.btSend = true;
        console.log(file, xhr);
    },
    'maxfilesexceeded': function(file) {
         $timeout(function() { 
            file._removeLink.click();
        }, 2000);
    }
}

Answer 4

The problem with the solutions provided is that you can only upload 1 file ever. In my case I needed to upload only 1 file at a time (on click or on drop).

This was my solution..

    Dropzone.options.myDropzone = {
        maxFiles: 2,
        init: function() {
            this.handleFiles = function(files) {
                var file, _i, _len, _results;
                _results = [];
                for (_i = 0, _len = files.length; _i < _len; _i++) {
                    file = files[_i];
                    _results.push(this.addFile(file));
                    // Make sure we don't handle more files than requested
                    if (this.options.maxFiles != null && this.options.maxFiles > 0 && _i >= (this.options.maxFiles - 1)) {
                        break;
                    }
                }
                return _results;
            };
            this._addFilesFromItems = function(items) {
                var entry, item, _i, _len, _results;
                _results = [];
                for (_i = 0, _len = items.length; _i < _len; _i++) {
                    item = items[_i];
                    if ((item.webkitGetAsEntry != null) && (entry = item.webkitGetAsEntry())) {
                        if (entry.isFile) {
                            _results.push(this.addFile(item.getAsFile()));
                        } else if (entry.isDirectory) {
                            _results.push(this._addFilesFromDirectory(entry, entry.name));
                        } else {
                            _results.push(void 0);
                        }
                    } else if (item.getAsFile != null) {
                        if ((item.kind == null) || item.kind === "file") {
                            _results.push(this.addFile(item.getAsFile()));
                        } else {
                            _results.push(void 0);
                        }
                    } else {
                        _results.push(void 0);
                    }
                    // Make sure we don't handle more files than requested
                    if (this.options.maxFiles != null && this.options.maxFiles > 0 && _i >= (this.options.maxFiles - 1)) {
                        break;
                    }
                }
                return _results;
            };
        }
    };

Hope this helps ;)

Answer 5

it looks like maxFiles is the parameter you are looking for.

https://github.com/enyo/dropzone/blob/master/src/dropzone.coffee#L667

Answer 6

Dropzone.options.dpzSingleFile = {
    paramName: "file", // The name that will be used to transfer the file
    maxFiles: 1,
    init: function() {
        this.on("maxfilesexceeded", function(file) {
            this.removeAllFiles();
            this.addFile(file);
        });
    }
};