Allow file urls option to download file or not (disposition header)

Author: CarsonF

src/components/file/file-url.controller.ts

@@ -5,6 +5,7 @@ import {
   HttpStatus,
   Inject,
   Param,
+  Query,
   Request,
   Response,
 } from '@nestjs/common';
@@ -29,6 +30,7 @@ export class FileUrlController {
   @Get(':fileId/:fileName?')
   async download(
     @Param('fileId') fileId: ID,
+    @Query('download') download: '' | undefined,
     @Request() request: IRequest,
     @Response() res: unknown,
   ) {
@@ -41,7 +43,7 @@ export class FileUrlController {
 
     // TODO authorization using session
 
-    const url = await this.files.getDownloadUrl(node);
+    const url = await this.files.getDownloadUrl(node, download != null);
     const cacheControl = this.files.determineCacheHeader(node);
 
     const { httpAdapter } = this.httpAdapterHost;

src/components/file/file-url.resolver-util.ts

@@ -1,4 +1,4 @@
-import { ResolveField } from '@nestjs/graphql';
+import { Args, ResolveField } from '@nestjs/graphql';
 import { stripIndent } from 'common-tags';
 import { URL } from 'url';
 
@@ -10,3 +10,14 @@ export const Resolver = () =>
       This url could require authentication.
     `,
   });
+
+export const DownloadArg = () =>
+  Args('download', {
+    description: stripIndent`
+      Whether the browser should download this file if opened directly
+
+      This sets the \`Content-Disposition\` header to \`attachment\` instead of \`inline\`.
+      https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition
+    `,
+    defaultValue: false,
+  });

src/components/file/file-version.resolver.ts

@@ -10,8 +10,11 @@ export class FileVersionResolver {
   constructor(protected readonly service: FileService) {}
 
   @FileUrl.Resolver()
-  async url(@Parent() node: FileVersion) {
-    return await this.service.getUrl(node);
+  async url(
+    @Parent() node: FileVersion,
+    @FileUrl.DownloadArg() download: boolean,
+  ) {
+    return await this.service.getUrl(node, download);
   }
 
   @ResolveField(() => URL, {

src/components/file/file.resolver.ts

@@ -77,8 +77,8 @@ export class FileResolver {
   }
 
   @FileUrl.Resolver()
-  async url(@Parent() node: File) {
-    return await this.service.getUrl(node);
+  async url(@Parent() node: File, @FileUrl.DownloadArg() download: boolean) {
+    return await this.service.getUrl(node, download);
   }
 
   @ResolveField(() => URL, {

src/components/file/file.service.ts

@@ -145,27 +145,28 @@ export class FileService {
     return data;
   }
 
-  async getUrl(node: FileNode) {
+  async getUrl(node: FileNode, download: boolean) {
     const url = withAddedPath(
       this.config.hostUrl,
       FileUrl.path,
       isFile(node) ? node.latestVersionId : node.id,
       encodeURIComponent(node.name),
     );
-    return url.toString();
+    return url.toString() + (download ? '?download' : '');
   }
 
-  async getDownloadUrl(node: FileNode): Promise<string> {
+  async getDownloadUrl(node: FileNode, download = true): Promise<string> {
     if (isDirectory(node)) {
       throw new InputException('View directories via GraphQL API');
     }
     const id = isFile(node) ? node.latestVersionId : node.id;
+    const disposition = download ? 'attachment' : 'inline';
     try {
       // before sending link, first check if object exists in s3
       await this.bucket.headObject(id);
       return await this.bucket.getSignedUrl(GetObject, {
         Key: id,
-        ResponseContentDisposition: `attachment; filename="${encodeURIComponent(
+        ResponseContentDisposition: `${disposition}; filename="${encodeURIComponent(
           node.name,
         )}"`,
         ResponseContentType: node.mimeType,

src/components/file/media-url.resolver.ts

@@ -12,9 +12,10 @@ export class MediaUrlResolver {
   @FileUrl.Resolver()
   async url(
     @Parent() media: Media,
+    @FileUrl.DownloadArg() download: boolean,
     @Loader(FileNodeLoader) files: LoaderOf<FileNodeLoader>,
   ) {
     const node = await files.load(media.file);
-    return await this.service.getUrl(node);
+    return await this.service.getUrl(node, download);
   }
 }