fix blob input in text viewer (#1942)

ng2-components/ng2-alfresco-viewer/src/components/txtViewer.component.ts

@@ -16,8 +16,7 @@
  */
 
 import { Component, Input } from '@angular/core';
-import { SimpleChange }    from '@angular/core';
-import { ContentService } from 'ng2-alfresco-core';
+import { SimpleChanges }    from '@angular/core';
 import { Http, Response, RequestOptions, ResponseContentType }  from '@angular/http';
 import 'rxjs/add/operator/toPromise';
 
@@ -32,36 +31,59 @@ export class TxtViewerComponent {
     urlFile: any;
 
     @Input()
-    blobFile: any;
+    blobFile: Blob;
 
     content: string;
 
-    constructor(private http: Http, private contentService: ContentService) {
+    constructor(private http: Http) {
     }
 
-    ngOnChanges(changes: SimpleChange) {
+    ngOnChanges(changes: SimpleChanges): Promise<any> {
+
         let blobFile = changes['blobFile'];
         if (blobFile && blobFile.currentValue) {
-            this.urlFile = this.contentService.createTrustedUrl(this.blobFile);
+            return this.readBlob(blobFile.currentValue);
         }
+
+        let urlFile = changes['urlFile'];
+        if (urlFile && urlFile.currentValue) {
+            return this.getUrlContent(urlFile.currentValue);
+        }
+
         if (!this.urlFile && !this.blobFile) {
             throw new Error('Attribute urlFile or blobFile is required');
         }
+    }
 
+    private getUrlContent(url: string): Promise<any> {
         return new Promise((resolve, reject) => {
-            this.getUrlContent(resolve, reject);
+
+            this.http.get(url, new RequestOptions({
+                responseType: ResponseContentType.Text
+            })).toPromise().then(
+                (res: Response) => {
+                    this.content = res.text();
+                    resolve();
+                }, (event) => {
+                    reject(event);
+                });
         });
     }
 
-    private getUrlContent(resolve, reject): void {
-        this.http.get(this.urlFile, new RequestOptions({
-            responseType: ResponseContentType.Text
-        })).toPromise().then(
-            (res: Response) => {
-                this.content =  res.text();
+    private readBlob(blob: Blob): Promise<any> {
+        return new Promise((resolve, reject) => {
+            let reader = new FileReader();
+
+            reader.onload = () => {
+                this.content = reader.result;
                 resolve();
-            }, (event) => {
-                reject(event);
-            });
+            };
+
+            reader.onerror = (error: ErrorEvent) => {
+                reject(error);
+            };
+
+            reader.readAsText(blob);
+        });
     }
 }