[fix] Force send attachment to always download and never open (#2908)

* [refactor] Introduce a file download service

* [refactor] Point platformUtilsService.saveFile() callers to fileDownloadService.download() instead

* [refactor] Remove platformUtilsService.saveFile()

* [fix] Force send attachments to always download and never open

* [fix] Remove the window property from FileDownloadRequest

* [fix] Move FileDownloadRequest to /abstractions/fileDownload

* [fix] Simplify FileDownloadRequest to a type

* [fix] Move BrowserApi.saveFile logic into BrowserFileDownloadService

* [fix] Use proper blob types for file downloads

* [fix] forceDownload -> downloadMethod on FileDownloadRequest

* [fix] Remove fileType from FileDownloadRequest

* [fix] Make fileType private

libs/common/src/abstractions/fileDownload/fileDownload.service.ts

@@ -0,0 +1,5 @@
+import { FileDownloadRequest } from "./fileDownloadRequest";
+
+export abstract class FileDownloadService {
+  download: (request: FileDownloadRequest) => void;
+}

libs/common/src/abstractions/fileDownload/fileDownloadBuilder.ts

@@ -0,0 +1,50 @@
+import { FileDownloadRequest } from "./fileDownloadRequest";
+
+export class FileDownloadBuilder {
+  get blobOptions(): any {
+    const options = this._request.blobOptions ?? {};
+    if (options.type == null) {
+      options.type = this.fileType;
+    }
+    return options;
+  }
+
+  get blob(): Blob {
+    if (this.blobOptions != null) {
+      return new Blob([this._request.blobData], this.blobOptions);
+    } else {
+      return new Blob([this._request.blobData]);
+    }
+  }
+
+  get downloadMethod(): "save" | "open" {
+    if (this._request.downloadMethod != null) {
+      return this._request.downloadMethod;
+    }
+    return this.fileType != "application/pdf" ? "save" : "open";
+  }
+
+  private get fileType() {
+    const fileNameLower = this._request.fileName.toLowerCase();
+    if (fileNameLower.endsWith(".pdf")) {
+      return "application/pdf";
+    } else if (fileNameLower.endsWith(".xlsx")) {
+      return "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
+    } else if (fileNameLower.endsWith(".docx")) {
+      return "application/vnd.openxmlformats-officedocument.wordprocessingml.document";
+    } else if (fileNameLower.endsWith(".pptx")) {
+      return "application/vnd.openxmlformats-officedocument.presentationml.presentation";
+    } else if (fileNameLower.endsWith(".csv")) {
+      return "text/csv";
+    } else if (fileNameLower.endsWith(".png")) {
+      return "image/png";
+    } else if (fileNameLower.endsWith(".jpg") || fileNameLower.endsWith(".jpeg")) {
+      return "image/jpeg";
+    } else if (fileNameLower.endsWith(".gif")) {
+      return "image/gif";
+    }
+    return null;
+  }
+
+  constructor(private readonly _request: FileDownloadRequest) {}
+}

libs/common/src/abstractions/fileDownload/fileDownloadRequest.ts

@@ -0,0 +1,6 @@
+export type FileDownloadRequest = {
+  fileName: string;
+  blobData: BlobPart;
+  blobOptions?: BlobPropertyBag;
+  downloadMethod?: "save" | "open";
+};

libs/common/src/abstractions/platformUtils.service.ts

@@ -18,7 +18,6 @@ export abstract class PlatformUtilsService {
   isMacAppStore: () => boolean;
   isViewOpen: () => Promise<boolean>;
   launchUri: (uri: string, options?: any) => void;
-  saveFile: (win: Window, blobData: any, blobOptions: any, fileName: string) => void;
   getApplicationVersion: () => Promise<string>;
   supportsWebAuthn: (win: Window) => boolean;
   supportsDuo: () => boolean;