- Implement of promise for filter function;

src/file-upload/file-drop.directive.ts

@@ -1,12 +1,14 @@
-import { Directive, EventEmitter, ElementRef, HostListener, Input, Output } from '@angular/core';
+import { Directive, ElementRef, EventEmitter, HostListener, Input, Output } from '@angular/core';
 
-import { FileUploader, FileUploaderOptions } from './file-uploader.class';
+import { FileUploader, FileUploaderOptions, FilterFunction } from './file-uploader.class';
 
 @Directive({ selector: '[ng2FileDrop]' })
 export class FileDropDirective {
   @Input() public uploader: FileUploader;
+  // tslint:disable-next-line:no-input-rename
+  @Input('ng2FileFilter') public filter: FilterFunction['fn'];
   @Output() public fileOver: EventEmitter<any> = new EventEmitter();
-  @Output() public onFileDrop: EventEmitter<File[]> = new EventEmitter<File[]>();
+  @Output() public onFileDrop: EventEmitter<FileList> = new EventEmitter<FileList>();
 
   protected element: ElementRef;
 
@@ -30,7 +32,10 @@ export class FileDropDirective {
     }
 
     let options = this.getOptions();
-    let filters = this.getFilters();
+    let filters = typeof this.filter === 'function' ? [{
+      name: 'ng2FileDropDirectiveFilter',
+      fn: this.filter
+    }, ...options.filters] : this.getFilters();
     this._preventAndStop(event);
     this.uploader.addToQueue(transfer.files, options, filters);
     this.fileOver.emit(false);
@@ -61,11 +66,11 @@ export class FileDropDirective {
     this.fileOver.emit(false);
   }
 
-  protected _getTransfer(event: any): any {
+  protected _getTransfer(event: any): DragEvent['dataTransfer'] {
     return event.dataTransfer ? event.dataTransfer : event.originalEvent.dataTransfer; // jQuery fix;
   }
 
-  protected _preventAndStop(event: any): any {
+  protected _preventAndStop(event: Event): any {
     event.preventDefault();
     event.stopPropagation();
   }

src/file-upload/file-select.directive.ts

@@ -1,10 +1,12 @@
-import { Directive, EventEmitter, ElementRef, Input, HostListener, Output } from '@angular/core';
+import { Directive, ElementRef, EventEmitter, HostListener, Input, Output } from '@angular/core';
 
-import { FileUploader } from './file-uploader.class';
+import { FileUploader, FilterFunction } from './file-uploader.class';
 
 @Directive({ selector: '[ng2FileSelect]' })
 export class FileSelectDirective {
   @Input() public uploader: FileUploader;
+  // tslint:disable-next-line:no-input-rename
+  @Input('ng2FileFilter') public filter: FilterFunction['fn'];
   @Output() public onFileSelected: EventEmitter<File[]> = new EventEmitter<File[]>();
 
   protected element: ElementRef;
@@ -29,7 +31,10 @@ export class FileSelectDirective {
   public onChange(): any {
     let files = this.element.nativeElement.files;
     let options = this.getOptions();
-    let filters = this.getFilters();
+    let filters = typeof this.filter === 'function' ? [{
+      name: 'ng2FileSelectDirectiveFilter',
+      fn: this.filter
+    }, ...options.filters] : this.getFilters();
 
     this.uploader.addToQueue(files, options, filters);
     this.onFileSelected.emit(files);

src/file-upload/file-uploader.class.ts

@@ -14,9 +14,9 @@ export interface Headers {
 
 export type ParsedResponseHeaders = { [headerFieldName: string]: string };
 
-export type FilterFunction = {
-  name: string,
-  fn: (item?: FileLikeObject, options?: FileUploaderOptions) => boolean
+export interface FilterFunction {
+  name: string;
+  fn(this: FileUploader, item?: FileLikeObject, options?: FileUploaderOptions, queueIndex?: number): boolean | Promise<boolean>;
 };
 
 export interface FileUploaderOptions {
@@ -89,26 +89,30 @@ export class FileUploader {
       this.options.filters.unshift({ name: 'mimeType', fn: this._mimeTypeFilter });
     }
 
-    for (let i = 0; i < this.queue.length; i++) {
-      this.queue[ i ].url = this.options.url;
+    for (const q of this.queue) {
+      q.url = this.options.url;
     }
   }
 
-  public addToQueue(files: File[], options?: FileUploaderOptions, filters?: FilterFunction[] | string): void {
+  public async addToQueue(files: FileList, options?: FileUploaderOptions, filters?: FilterFunction[] | string): Promise<void> {
     let list: File[] = [];
-    for (let file of files) {
-      list.push(file);
+    // tslint:disable-next-line:prefer-for-of
+    for (let i = 0; i < files.length; i++) {
+      list.push(files[i]);
     }
+
     let arrayOfFilters = this._getFilters(filters);
     let count = this.queue.length;
     let addedFileItems: FileItem[] = [];
-    list.map((some: File) => {
+    let idx = 0;
+
+    for (const some of list) {
       if (!options) {
         options = this.options;
       }
 
       let temp = new FileLikeObject(some);
-      if (this._isValidFile(temp, arrayOfFilters, options)) {
+      if (await this._isValidFile(temp, arrayOfFilters, options, idx++)) {
         let fileItem = new FileItem(this, some, options);
         addedFileItems.push(fileItem);
         this.queue.push(fileItem);
@@ -117,7 +121,7 @@ export class FileUploader {
         let filter = arrayOfFilters[this._failFilterIndex];
         this._onWhenAddingFileFailed(temp, filter, options);
       }
-    });
+    }
     if (this.queue.length !== count) {
       this._onAfterAddingAll(addedFileItems);
       this.progress = this._getTotalProgress();
@@ -420,12 +424,18 @@ export class FileUploader {
     return this.options.queueLimit === undefined || this.queue.length < this.options.queueLimit;
   }
 
-  protected _isValidFile(file: FileLikeObject, filters: FilterFunction[], options: FileUploaderOptions): boolean {
+  protected async _isValidFile(file: FileLikeObject, filters: FilterFunction[], options: FileUploaderOptions, queueIndex: number) {
     this._failFilterIndex = -1;
-    return !filters.length ? true : filters.every((filter: FilterFunction) => {
+
+    for (const filter of filters) {
       this._failFilterIndex++;
-      return filter.fn.call(this, file, options);
-    });
+
+      if (!(await Promise.resolve(filter.fn.call(this, file, options, queueIndex)))) {
+        return false;
+      }
+    }
+
+    return true;
   }
 
   protected _isSuccessCode(status: number): boolean {