feat: Individual page export in Markdown and HTML formats (#80)

* fix maths node

* render default html width

* Add page export module
* with support for html and markdown exports

* Page export UI
* Add PDF print too

* remove unused import

apps/server/src/app.module.ts

@@ -12,6 +12,7 @@ import { QueueModule } from './integrations/queue/queue.module';
 import { StaticModule } from './integrations/static/static.module';
 import { EventEmitterModule } from '@nestjs/event-emitter';
 import { HealthModule } from './integrations/health/health.module';
+import { ExportModule } from './integrations/export/export.module';
 
 @Module({
   imports: [
@@ -23,6 +24,7 @@ import { HealthModule } from './integrations/health/health.module';
     QueueModule,
     StaticModule,
     HealthModule,
+    ExportModule,
     StorageModule.forRootAsync({
       imports: [EnvironmentModule],
     }),

apps/server/src/collaboration/collaboration.util.ts

@@ -60,7 +60,7 @@ export const tiptapExtensions = [
   Callout,
 ] as any;
 
-export function jsonToHtml(tiptapJson: JSONContent) {
+export function jsonToHtml(tiptapJson: any) {
   return generateHTML(tiptapJson, tiptapExtensions);
 }
 

apps/server/src/integrations/export/dto/export-dto.ts

@@ -0,0 +1,26 @@
+import {
+  IsBoolean,
+  IsIn,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+} from 'class-validator';
+
+export enum ExportFormat {
+  HTML = 'html',
+  Markdown = 'markdown',
+}
+
+export class ExportPageDto {
+  @IsString()
+  @IsNotEmpty()
+  pageId: string;
+
+  @IsString()
+  @IsIn(['html', 'markdown'])
+  format: ExportFormat;
+
+  @IsOptional()
+  @IsBoolean()
+  includeFiles?: boolean;
+}

apps/server/src/integrations/export/export.controller.ts

@@ -0,0 +1,69 @@
+import {
+  Body,
+  Controller,
+  ForbiddenException,
+  HttpCode,
+  HttpStatus,
+  NotFoundException,
+  Post,
+  Res,
+  UseGuards,
+} from '@nestjs/common';
+import { ExportService } from './export.service';
+import { ExportPageDto } from './dto/export-dto';
+import { AuthUser } from '../../common/decorators/auth-user.decorator';
+import { User } from '@docmost/db/types/entity.types';
+import SpaceAbilityFactory from '../../core/casl/abilities/space-ability.factory';
+import { JwtAuthGuard } from '../../common/guards/jwt-auth.guard';
+import { PageRepo } from '@docmost/db/repos/page/page.repo';
+import {
+  SpaceCaslAction,
+  SpaceCaslSubject,
+} from '../../core/casl/interfaces/space-ability.type';
+import { FastifyReply } from 'fastify';
+import { sanitize } from 'sanitize-filename-ts';
+import { getExportExtension } from './utils';
+import { getMimeType } from '../../common/helpers';
+
+@Controller()
+export class ImportController {
+  constructor(
+    private readonly importService: ExportService,
+    private readonly pageRepo: PageRepo,
+    private readonly spaceAbility: SpaceAbilityFactory,
+  ) {}
+
+  @UseGuards(JwtAuthGuard)
+  @HttpCode(HttpStatus.OK)
+  @Post('pages/export')
+  async exportPage(
+    @Body() dto: ExportPageDto,
+    @AuthUser() user: User,
+    @Res() res: FastifyReply,
+  ) {
+    const page = await this.pageRepo.findById(dto.pageId, {
+      includeContent: true,
+    });
+
+    if (!page) {
+      throw new NotFoundException('Page not found');
+    }
+
+    const ability = await this.spaceAbility.createForUser(user, page.spaceId);
+    if (ability.cannot(SpaceCaslAction.Read, SpaceCaslSubject.Page)) {
+      throw new ForbiddenException();
+    }
+
+    const rawContent = await this.importService.exportPage(dto.format, page);
+
+    const fileExt = getExportExtension(dto.format);
+    const fileName = sanitize(page.title || 'Untitled') + fileExt;
+
+    res.headers({
+      'Content-Type': getMimeType(fileExt),
+      'Content-Disposition': 'attachment; filename="' + fileName + '"',
+    });
+
+    res.send(rawContent);
+  }
+}

apps/server/src/integrations/export/export.module.ts

@@ -0,0 +1,9 @@
+import { Module } from '@nestjs/common';
+import { ExportService } from './export.service';
+import { ImportController } from './export.controller';
+
+@Module({
+  providers: [ExportService],
+  controllers: [ImportController],
+})
+export class ExportModule {}

apps/server/src/integrations/export/export.service.ts

@@ -0,0 +1,34 @@
+import { Injectable } from '@nestjs/common';
+import { jsonToHtml } from '../../collaboration/collaboration.util';
+import { turndown } from './turndown-utils';
+import { ExportFormat } from './dto/export-dto';
+import { Page } from '@docmost/db/types/entity.types';
+
+@Injectable()
+export class ExportService {
+  async exportPage(format: string, page: Page) {
+    const titleNode = {
+      type: 'heading',
+      attrs: { level: 1 },
+      content: [{ type: 'text', text: page.title }],
+    };
+
+    let prosemirrorJson: any = page.content || { type: 'doc', content: [] };
+
+    if (page.title) {
+      prosemirrorJson.content.unshift(titleNode);
+    }
+
+    const pageHtml = jsonToHtml(prosemirrorJson);
+
+    if (format === ExportFormat.HTML) {
+      return `<!DOCTYPE html><html><head><title>${page.title}</title></head><body>${pageHtml}</body></html>`;
+    }
+
+    if (format === ExportFormat.Markdown) {
+      return turndown(pageHtml);
+    }
+
+    return;
+  }
+}

apps/server/src/integrations/export/turndown-utils.ts

@@ -0,0 +1,100 @@
+import * as TurndownService from '@joplin/turndown';
+import * as TurndownPluginGfm from '@joplin/turndown-plugin-gfm';
+
+export function turndown(html: string): string {
+  const turndownService = new TurndownService({
+    headingStyle: 'atx',
+    codeBlockStyle: 'fenced',
+    hr: '---',
+    bulletListMarker: '-',
+  });
+  const tables = TurndownPluginGfm.tables;
+  const strikethrough = TurndownPluginGfm.strikethrough;
+  const highlightedCodeBlock = TurndownPluginGfm.highlightedCodeBlock;
+
+  turndownService.use([
+    tables,
+    strikethrough,
+    highlightedCodeBlock,
+    taskList,
+    callout,
+    toggleListTitle,
+    toggleListBody,
+    listParagraph,
+  ]);
+
+  return turndownService.turndown(html).replaceAll('<br>', ' ');
+}
+
+function listParagraph(turndownService: TurndownService) {
+  turndownService.addRule('paragraph', {
+    filter: ['p'],
+    replacement: (content: any, node: HTMLInputElement) => {
+      if (node.parentElement?.nodeName === 'LI') {
+        return content;
+      }
+
+      return `\n\n${content}\n\n`;
+    },
+  });
+}
+
+function callout(turndownService: TurndownService) {
+  turndownService.addRule('callout', {
+    filter: function (node: HTMLInputElement) {
+      return (
+        node.nodeName === 'DIV' && node.getAttribute('data-type') === 'callout'
+      );
+    },
+    replacement: function (content: any, node: HTMLInputElement) {
+      const calloutType = node.getAttribute('data-callout-type');
+      return `\n\n:::${calloutType}\n${content.trim()}\n:::\n\n`;
+    },
+  });
+}
+
+function taskList(turndownService: TurndownService) {
+  turndownService.addRule('taskListItem', {
+    filter: function (node: HTMLInputElement) {
+      return (
+        node.getAttribute('data-type') === 'taskItem' &&
+        node.parentNode.nodeName === 'UL'
+      );
+    },
+    replacement: function (content: any, node: HTMLInputElement) {
+      const checkbox = node.querySelector(
+        'input[type="checkbox"]',
+      ) as HTMLInputElement;
+      const isChecked = checkbox.checked;
+
+      return `- ${isChecked ? '[x]' : '[ ]'}  ${content.trim()} \n`;
+    },
+  });
+}
+
+function toggleListTitle(turndownService: TurndownService) {
+  turndownService.addRule('toggleListTitle', {
+    filter: function (node: HTMLInputElement) {
+      return (
+        node.nodeName === 'SUMMARY' && node.parentNode.nodeName === 'DETAILS'
+      );
+    },
+    replacement: function (content: any, node: HTMLInputElement) {
+      return '- ' + content;
+    },
+  });
+}
+
+function toggleListBody(turndownService: TurndownService) {
+  turndownService.addRule('toggleListContent', {
+    filter: function (node: HTMLInputElement) {
+      return (
+        node.getAttribute('data-type') === 'detailsContent' &&
+        node.parentNode.nodeName === 'DETAILS'
+      );
+    },
+    replacement: function (content: any, node: HTMLInputElement) {
+      return `   ${content.replace(/\n/g, '\n    ')}  `;
+    },
+  });
+}

apps/server/src/integrations/export/utils.ts

@@ -0,0 +1,12 @@
+import { ExportFormat } from './dto/export-dto';
+
+export function getExportExtension(format: string) {
+  if (format === ExportFormat.HTML) {
+    return '.html';
+  }
+
+  if (format === ExportFormat.Markdown) {
+    return '.md';
+  }
+  return;
+}