GH-1905: Implemented the file download functionality.

Closes #1905.

Signed-off-by: Akos Kitta <kittaakos@gmail.com>

examples/browser/package.json

@@ -53,4 +53,4 @@
   "devDependencies": {
     "@theia/cli": "^0.3.11"
   }
-}
+}

examples/electron/package.json

@@ -52,4 +52,4 @@
   "devDependencies": {
     "@theia/cli": "^0.3.11"
   }
-}
+}

packages/core/package.json

@@ -9,7 +9,7 @@
     "@theia/application-package": "^0.3.11",
     "@types/body-parser": "^1.16.4",
     "@types/bunyan": "^1.8.0",
-    "@types/express": "^4.0.36",
+    "@types/express": "^4.16.0",
     "@types/lodash.debounce": "4.0.3",
     "@types/lodash.throttle": "^4.1.3",
     "@types/route-parser": "^0.1.1",
@@ -20,7 +20,7 @@
     "bunyan": "^1.8.10",
     "electron": "1.8.2-beta.5",
     "es6-promise": "^4.2.4",
-    "express": "^4.15.3",
+    "express": "^4.16.3",
     "file-icons-js": "^1.0.3",
     "font-awesome": "^4.7.0",
     "inversify": "^4.2.0",
@@ -80,4 +80,4 @@
   "nyc": {
     "extends": "../../configs/nyc.json"
   }
-}
+}

packages/core/src/common/objects.ts

@@ -30,3 +30,10 @@ const _hasOwnProperty = Object.prototype.hasOwnProperty;
 export function notEmpty<T>(arg: T | undefined | null): arg is T {
     return arg !== undefined && arg !== null;
 }
+
+/**
+ * `true` if the argument is an empty object. Otherwise, `false`.
+ */
+export function isEmpty(arg: Object): boolean {
+    return Object.keys(arg).length === 0 && arg.constructor === Object;
+}

packages/filesystem/package.json

@@ -5,13 +5,25 @@
   "dependencies": {
     "@theia/core": "^0.3.11",
     "@types/base64-js": "^1.2.5",
+    "@types/body-parser": "^1.17.0",
     "@types/fs-extra": "^4.0.2",
+    "@types/mime-types": "^2.1.0",
+    "@types/rimraf": "^2.0.2",
     "@types/touch": "0.0.1",
+    "@types/tar-fs": "^1.16.1",
+    "@types/uuid": "^3.4.3",
     "base64-js": "^1.2.1",
+    "body-parser": "^1.18.3",
     "fs-extra": "^4.0.2",
+    "http-status-codes": "^1.3.0",
+    "mime-types": "^2.1.18",
     "mv": "^2.1.1",
     "touch": "^3.1.0",
-    "trash": "^4.0.1"
+    "trash": "^4.0.1",
+    "rimraf": "^2.6.2",
+    "uuid": "^3.2.1",
+    "tar-fs": "^1.16.2",
+    "zip-dir": "^1.0.2"
   },
   "publishConfig": {
     "access": "public"
@@ -20,6 +32,10 @@
     {
       "frontend": "lib/browser/filesystem-frontend-module",
       "backend": "lib/node/filesystem-backend-module"
+    },
+    {
+      "frontend": "lib/browser/download/file-download-frontend-module",
+      "backend": "lib/node/download/file-download-backend-module"
     }
   ],
   "keywords": [
@@ -53,4 +69,4 @@
   "nyc": {
     "extends": "../../configs/nyc.json"
   }
-}
+}

packages/filesystem/src/browser/download/file-download-command-contribution.ts

@@ -0,0 +1,86 @@
+/*
+ * Copyright (C) 2018 TypeFox and others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import { inject, injectable } from 'inversify';
+import URI from '@theia/core/lib/common/uri';
+import { notEmpty } from '@theia/core/lib/common/objects';
+import { UriSelection } from '@theia/core/lib/common/selection';
+import { SelectionService } from '@theia/core/lib/common/selection-service';
+import { Command, CommandContribution, CommandRegistry } from '@theia/core/lib/common/command';
+import { UriAwareCommandHandler, UriCommandHandler } from '@theia/core/lib/common/uri-command-handler';
+import { FileDownloadService } from './file-download-service';
+
+@injectable()
+export class FileDownloadCommandContribution implements CommandContribution {
+
+    @inject(FileDownloadService)
+    protected readonly downloadService: FileDownloadService;
+
+    @inject(SelectionService)
+    protected readonly selectionService: SelectionService;
+
+    registerCommands(registry: CommandRegistry): void {
+        const options = {
+            multi: true,
+            isValid: this.isValid.bind(this)
+        };
+        const handler = new UriAwareCommandHandler<URI[]>(this.selectionService, this.downloadHandler(), options);
+        registry.registerCommand(FileDownloadCommands.DOWNLOAD, handler);
+    }
+
+    protected downloadHandler(): UriCommandHandler<URI[]> {
+        return {
+            execute: uri => this.executeDownload(uri),
+            isEnabled: (uri, args) => this.isDownloadEnabled(uri, args),
+            isVisible: (uri, args) => this.isDownloadVisible(uri, args),
+        };
+    }
+
+    protected async executeDownload(uris: URI[]): Promise<void> {
+        this.downloadService.download(uris);
+    }
+
+    // tslint:disable-next-line:no-any
+    protected isDownloadEnabled(uri: Object | undefined, ...args: any[]): boolean {
+        return this.getUris(uri).length > 0;
+    }
+
+    // tslint:disable-next-line:no-any
+    protected isDownloadVisible(uri: Object | undefined, ...args: any[]): boolean {
+        return this.isDownloadEnabled(uri, args);
+    }
+
+    protected isValid(uris: URI[]): boolean {
+        return uris.every(u => u.scheme === 'file');
+    }
+
+    protected getUris(uri: Object | undefined): URI[] {
+        if (uri === undefined) {
+            return [];
+        }
+        return (Array.isArray(uri) ? uri : [uri]).map(u => this.getUri(u)).filter(notEmpty);
+    }
+
+    protected getUri(uri: Object | undefined): URI | undefined {
+        if (uri instanceof URI) {
+            return uri;
+        }
+        if (UriSelection.is(uri)) {
+            return uri.uri;
+        }
+        return undefined;
+    }
+
+}
+
+export namespace FileDownloadCommands {
+
+    export const DOWNLOAD: Command = {
+        id: 'file.download'
+    };
+
+}

packages/filesystem/src/browser/download/file-download-frontend-module.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2018 TypeFox and others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import { ContainerModule } from 'inversify';
+import { CommandContribution } from '@theia/core/lib/common/command';
+import { FileDownloadService } from './file-download-service';
+import { FileDownloadCommandContribution } from './file-download-command-contribution';
+
+export default new ContainerModule(bind => {
+    bind(FileDownloadService).toSelf().inSingletonScope();
+    bind(CommandContribution).to(FileDownloadCommandContribution).inSingletonScope();
+});

packages/filesystem/src/browser/download/file-download-service.ts

@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2018 TypeFox and others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+import { inject, injectable } from 'inversify';
+import URI from '@theia/core/lib/common/uri';
+import { ILogger } from '@theia/core/lib/common/logger';
+import { Endpoint } from '@theia/core/lib/browser/endpoint';
+import { FileSystem } from '../../common/filesystem';
+import { FileDownloadData } from '../../common/download/file-download-data';
+
+@injectable()
+export class FileDownloadService {
+
+    protected anchor: HTMLAnchorElement | undefined;
+
+    @inject(ILogger)
+    protected readonly logger: ILogger;
+
+    @inject(FileSystem)
+    protected readonly fileSystem: FileSystem;
+
+    async download(uris: URI[]): Promise<void> {
+        if (uris.length === 0) {
+            return;
+        }
+        try {
+            const response = await fetch(this.request(uris));
+            const title = await this.title(response, uris);
+            const { status, statusText } = response;
+            if (status === 200) {
+                this.forceDownload(response, title);
+            } else {
+                throw new Error(`Received unexpected status code: ${status}. [${statusText}]`);
+            }
+        } catch (e) {
+            this.logger.error(`Error occurred when downloading: ${uris.map(u => u.toString(true))}.`, e);
+        }
+    }
+
+    protected async forceDownload(response: Response, title: string): Promise<void> {
+        let url: string | undefined;
+        try {
+            const blob = await response.blob();
+            url = URL.createObjectURL(blob);
+            if (this.anchor === undefined) {
+                this.anchor = document.createElement('a');
+                this.anchor.style.display = 'none';
+            }
+            this.anchor.href = url;
+            this.anchor.download = title;
+            this.anchor.click();
+        } finally {
+            if (url) {
+                URL.revokeObjectURL(url);
+            }
+        }
+    }
+
+    protected async title(response: Response, uris: URI[]): Promise<string> {
+        let title = (response.headers.get('Content-Disposition') || '').split('attachment; filename=').pop();
+        if (title) {
+            return title;
+        }
+        // tslint:disable-next-line:whitespace
+        const [uri,] = uris;
+        if (uris.length === 1) {
+            const stat = await this.fileSystem.getFileStat(uri.toString());
+            if (stat === undefined) {
+                throw new Error(`Unexpected error occurred when downloading file. Files does not exist. URI: ${uri.toString(true)}.`);
+            }
+            title = uri.path.base;
+            return stat.isDirectory ? `${title}.tar` : title;
+        }
+        return `${uri.parent.path.name}.tar`;
+    }
+
+    protected request(uris: URI[]): Request {
+        const url = this.url(uris);
+        const init = this.requestInit(uris);
+        return new Request(url, init);
+    }
+
+    protected requestInit(uris: URI[]): RequestInit {
+        if (uris.length === 1) {
+            return {
+                body: undefined,
+                method: 'GET'
+            };
+        }
+        return {
+            method: 'PUT',
+            body: JSON.stringify(this.body(uris)),
+            headers: new Headers({ 'Content-Type': 'application/json' }),
+        };
+    }
+
+    protected body(uris: URI[]): FileDownloadData {
+        return {
+            uris: uris.map(u => u.toString(true))
+        };
+    }
+
+    protected url(uris: URI[]): string {
+        const endpoint = this.endpoint();
+        if (uris.length === 1) {
+            // tslint:disable-next-line:whitespace
+            const [uri,] = uris;
+            return `${endpoint}/?uri=${uri.toString()}`;
+        }
+        return endpoint;
+
+    }
+
+    protected endpoint(): string {
+        const url = new Endpoint({ path: 'files' }).getRestUrl().toString();
+        return url.endsWith('/') ? url.slice(0, -1) : url;
+    }
+
+}

packages/filesystem/src/common/download/README.md

@@ -0,0 +1,30 @@
+# Theia - File Download
+
+Provides the file download contribution to the `Files` navigator.
+
+Supports single and multi file downloads.
+ 1. A single file will be downloaded as is.
+ 2. Folders will be downloaded az tar archives.
+ 3. When downloading multiple files, the name of the closest common parent directory will be used for the archive.
+ 4. When downloading multiple files from multiple disks (for instance: `C:\` and `D:\` on Windows), then we apply rule `3.` per disks and we tar the tars.
+
+### REST API
+
+ - To download a single file or folder use the following endpoint: `GET /files/?uri=/encoded/file/uri/to/the/resource`.
+   - Example: `curl -X GET http://localhost:3000/files/?uri=file:///Users/akos.kitta/git/theia/package.json`.
+
+ - To download multiple files (from the same folder) use the `PUT /files/` endpoint with the `application/json` content type header and the following body format:
+    ```json
+    {
+        "uri": [
+            "/encoded/file/uri/to/the/resource",
+            "/another/encoded/file/uri/to/the/resource"
+        ]
+    }
+    ```
+   ```
+   curl -X PUT -H "Content-Type: application/json" -d '{ "uris": ["file:///Users/akos.kitta/git/theia/package.json", "file:///Users/akos.kitta/git/theia/README.md"] }' http://localhost:3000/files/
+   ```
+
+## License
+[Apache-2.0](https://github.com/theia-ide/theia/blob/master/LICENSE)

packages/filesystem/src/common/download/file-download-data.ts

@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2018 TypeFox and others.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+export interface FileDownloadData {
+    readonly uris: string[];
+}
+
+export namespace FileDownloadData {
+    export function is(arg: Object | undefined): arg is FileDownloadData {
+        return !!arg && 'uris' in arg;
+    }
+}

packages/filesystem/src/common/filesystem.ts

@@ -15,7 +15,7 @@ export const FileSystem = Symbol("FileSystem");
 export interface FileSystem extends JsonRpcServer<FileSystemClient> {
 
     /**
-     * Returns the filestat for the given uri.
+     * Returns the file stat for the given URI.
      *
      * If the uri points to a folder it will contain one level of unresolved children.
      *
@@ -102,7 +102,7 @@ export interface FileSystem extends JsonRpcServer<FileSystemClient> {
     getRoots(): Promise<FileStat[]>;
 
     /**
-     * Returns a promise the resolves to a file stat representing the current user's home directory.
+     * Returns a promise that resolves to a file stat representing the current user's home directory.
      */
     getCurrentUserHome(): Promise<FileStat | undefined>;