How to limit the number of dropzone.js files uploaded?

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.

Answer 1

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 ;)