Download messages at a folder level

A few changes:
- Right clicking on a folder (excluding Drafts, Unread, Starred) gives an option to "Export the %@ folder"
- In order to get this to work I needed to add the property/reference to the existing DB column `remoteFolderId`
- Sanitise regex utilities for paths
- Downloading a single email now has it's name sanitised to stop saving errors (i.e slashes, colons, etc.)
- Prettier/lint changes (for best practices)

**Issues:**
- Needs translations
- long running process ties up mailsync - need to deprioritise tasks or have a `Action.queueBackgroundTask` option

app/internal_packages/account-sidebar/lib/sidebar-item.ts

@@ -11,10 +11,18 @@ import {
   Actions,
   RegExpUtils,
   localized,
+  MessageStore,
+  GetMessageRFC2822Task,
+  MutableQuerySubscription,
+  Thread,
+  Message,
+  DatabaseStore,
+  Folder,
 } from 'mailspring-exports';
 
 import * as SidebarActions from './sidebar-actions';
 import { ISidebarItem } from './types';
+import { dialog } from '@electron/remote';
 
 const idForCategories = categories => _.pluck(categories, 'id').join('-');
 
@@ -74,6 +82,39 @@ const onDeleteItem = function (item) {
   );
 };
 
+const onExportItem = async function(item) {
+  const filepath = await dialog.showOpenDialog({
+    properties: ['openDirectory', 'createDirectory'],
+  });
+
+  if (!filepath.canceled && filepath.filePaths[0]) {
+    await DatabaseStore.findAll<Message>(Message, { remoteFolderId: this.id }).then(messages => {
+      const tasks = [];
+
+      messages.forEach(message => {
+        const savePath = `${filepath.filePaths[0]}/${
+          message.subject
+        } - ${message.date.toLocaleString('sv-SE')} - ${message.id.substring(0, 10)}.eml`
+          .replace(/:/g, ';')
+          .replace(RegExpUtils.illegalPathCharacters(), '-')
+          .replace(RegExpUtils.unicodeControlCharacters(), '-');
+
+        tasks.push(
+          new GetMessageRFC2822Task({
+            messageId: message.id,
+            accountId: message.accountId,
+            filepath: savePath,
+          })
+        );
+      });
+
+      if (tasks.length > 0) {
+        Actions.queueTasks(tasks);
+      }
+    });
+  }
+};
+
 const onEditItem = function(item, value) {
   let newDisplayName;
   if (!value) {
@@ -134,6 +175,7 @@ export default class SidebarItem {
         counterStyle,
         onDelete: opts.deletable ? onDeleteItem : undefined,
         onEdited: opts.editable ? onEditItem : undefined,
+        onExport: opts.exportable ? onExportItem : undefined,
         onCollapseToggled: toggleItemCollapsed,
 
         onDrop(item, event) {
@@ -190,6 +232,9 @@ export default class SidebarItem {
     if (opts.editable == null) {
       opts.editable = true;
     }
+
+    opts.exportable = true;
+
     opts.contextMenuLabel = contextMenuLabel;
     return this.forPerspective(id, perspective, opts);
   }

app/internal_packages/account-sidebar/lib/types.ts

@@ -20,6 +20,7 @@ export interface ISidebarItem {
 
   deletable?: boolean;
   editable?: boolean;
+  exportable?: boolean;
 }
 
 export interface ISidebarSection {

app/internal_packages/message-list/lib/message-controls.tsx

@@ -9,6 +9,7 @@ import {
   GetMessageRFC2822Task,
   Thread,
   Message,
+  RegExpUtils,
 } from 'mailspring-exports';
 import { RetinaImg, ButtonDropdown, Menu } from 'mailspring-component-kit';
 import { ipcRenderer, SaveDialogReturnValue } from 'electron';
@@ -162,10 +163,13 @@ export default class MessageControls extends React.Component<MessageControlsProp
     const { message } = this.props;
 
     const filepath = await dialog.showSaveDialog({
-      filters: [{ name: 'Email', extensions: ['.eml'] }],
+      filters: [{ name: 'Email', extensions: ['eml'] }],
-      defaultPath: `${message.subject} - ${new Date().toLocaleDateString(
+      defaultPath: `${message.subject} - ${message.date.toLocaleString(
         'sv-SE'
-      )} - ${message.id.substring(0, 10)}.eml`,
+      )} - ${message.id.substring(0, 10)}.eml`
+        .replace(/:/g, ';')
+        .replace(RegExpUtils.illegalPathCharacters(), '-')
+        .replace(RegExpUtils.unicodeControlCharacters(), '-'),
     });
 
     if (!filepath.canceled && filepath.filePath) {

app/lang/en.json

@@ -223,6 +223,7 @@
   "Explore Mailspring Pro": "Explore Mailspring Pro",
   "Export Failed": "Export Failed",
   "Export Raw Data": "Export Raw Data",
+  "Export the %@ folder": "Export the %@ folder",
   "Facebook URL": "Facebook URL",
   "Failed to load \"%@\"": "Failed to load \"%@\"",
   "Failed to load config.json: %@": "Failed to load config.json: %@",

app/src/components/outline-view-item.tsx

@@ -191,7 +191,11 @@ class OutlineViewItem extends Component<OutlineViewItemProps, OutlineViewItemSta
   };
 
   _shouldShowContextMenu = () => {
-    return this.props.item.onDelete != null || this.props.item.onEdited != null;
+    return (
+      this.props.item.onDelete != null ||
+      this.props.item.onEdited != null ||
+      this.props.item.onExport != null
+    );
   };
 
   _shouldAcceptDrop = event => {
@@ -244,6 +248,10 @@ class OutlineViewItem extends Component<OutlineViewItemProps, OutlineViewItemSta
     }
   };
 
+  _onExport = () => {
+    this._runCallback('onExport');
+  };
+
   _onInputFocus = event => {
     const input = event.target;
     input.selectionStart = input.selectionEnd = input.value.length;
@@ -273,7 +281,7 @@ class OutlineViewItem extends Component<OutlineViewItemProps, OutlineViewItemSta
     if (this.props.item.onEdited) {
       menu.append(
         new MenuItem({
-          label: `${localized(`Rename`)} ${contextMenuLabel}`,
+          label: `${localized('Rename')} ${contextMenuLabel}`,
           click: this._onEdit,
         })
       );
@@ -282,11 +290,19 @@ class OutlineViewItem extends Component<OutlineViewItemProps, OutlineViewItemSta
     if (this.props.item.onDelete) {
       menu.append(
         new MenuItem({
-          label: `${localized(`Delete`)} ${contextMenuLabel}`,
+          label: `${localized('Delete')} ${contextMenuLabel}`,
           click: this._onDelete,
         })
       );
     }
+
+    menu.append(
+      new MenuItem({
+        label: localized('Export the %@ folder', item.name ?? ''),
+        click: this._onExport,
+      })
+    );
+
     menu.popup({});
   };
 

app/src/components/outline-view.tsx

@@ -27,6 +27,7 @@ export interface IOutlineViewItem {
   onSelect?: (...args: any[]) => any;
   onDelete?: (...args: any[]) => any;
   onEdited?: (...args: any[]) => any;
+  onExport?: (...args: any[]) => any;
 }
 
 interface OutlineViewProps {
@@ -184,7 +185,7 @@ export class OutlineView extends Component<OutlineViewProps, OutlineViewState> {
 
   _renderHeading(allowCreate, collapsed, collapsible) {
     const collapseLabel = collapsed ? localized('Show') : localized('Hide');
-    let style: CSSProperties = {}
+    let style: CSSProperties = {};
     if (this.props.titleColor) {
       style = {
         height: '50%',
@@ -192,7 +193,7 @@ export class OutlineView extends Component<OutlineViewProps, OutlineViewState> {
         borderLeftWidth: '4px',
         borderLeftColor: this.props.titleColor,
         borderLeftStyle: 'solid',
-      }
+      };
     }
     return (
       <DropZone

app/src/flux/models/message.ts

@@ -177,6 +177,11 @@ export class Message extends ModelWithMetadata {
       modelKey: 'folder',
       itemClass: Folder,
     }),
+
+    remoteFolderId: Attributes.String({
+      queryable: true,
+      modelKey: 'remoteFolderId',
+    }),
   };
 
   public subject: string;
@@ -198,6 +203,7 @@ export class Message extends ModelWithMetadata {
   public replyToHeaderMessageId: string;
   public forwardedHeaderMessageId: string;
   public folder: Folder;
+  public remoteFolderId: string;
 
   /** indicates that "body" is plain text, not HTML */
   public plaintext: boolean;

app/src/regexp-utils.ts

@@ -317,6 +317,20 @@ const RegExpUtils = {
   subcategorySplitRegex() {
     return /[./\\]/g;
   },
+
+  // Finds illegal path characters
+  // https://kb.acronis.com/content/39790
+  illegalPathCharacters() {
+    return /[/?<>\\:*|"]/g;
+  },
+
+  // Finds Unicode Control codes
+  // C0 0x00-0x1f & C1 (0x80-0x9f)
+  // http://en.wikipedia.org/wiki/C0_and_C1_control_codes
+  unicodeControlCharacters() {
+    // eslint-disable-next-line no-control-regex
+    return /[\x00-\x1f\x80-\x9f]/g;
+  },
 };
 
 export default RegExpUtils;