Text Editor and PDF Viewer in DSM

Two small but useful DSM apps: Text Editor for plain text and code in the browser, PDF Viewer for reading PDFs without Adobe. You rarely open them directly — they launch automatically when you click matching files in File Station or Drive.

Text Editor

What it can do

• Open and edit plain-text files (.txt, .md, .csv, .log)
• Code files with syntax highlighting for >50 languages:
  • JavaScript, TypeScript, Python, Go, Rust
  • HTML, CSS, SCSS
  • PHP, Ruby, Java, C/C++
  • Shell scripts
  • Config files (YAML, JSON, TOML, INI, XML)
• Find and replace (Ctrl+F / Cmd+F)
• Multi-line editing with block selection
• Auto-indentation
• Line numbering (toggleable)
• Theme selection (light / dark)

How you open it

In File Station or Drive: click a text file → it opens automatically in the Text Editor (browser-based).

Or open Text Editor from the DSM main menu, then load a file.

Use cases

• Quickly look at a .gitignore file
• Inspect config files
• Keep notes in .md format (an alternative to Note Station)
• Store code snippets

What it can’t do

• Not an IDE: no debugger, no code completion like VS Code
• No plugin library
• No integrated version control (use the Drive versioning)
• Performance with very large files: above 5 MB it gets sluggish

For serious coding: a local IDE (VS Code, JetBrains) with sync via the Drive client. Text Editor is for “just having a quick look / small edits on the go”.

Saving

Ctrl+S / Cmd+S or toolbar → Save. The file is saved to the cloud.

While editing: auto-save every 30 seconds plus on manual save.

PDF Viewer

What it can do

• Display PDF files in the browser
• Zoom (Ctrl+Plus / Cmd+Plus or mouse wheel)
• Search within the content
• Bookmarks (bookmarks in the PDF)
• Print (via the browser print dialog)
• Annotation: highlighting, notes, drawing
  • Highlight marker
  • Free-text notes
  • Comments
  • Stamps
• Fill in form fields (PDF forms with input fields)
• Extract pages (save individual pages as a new PDF)

How you open it

Click a .pdf in File Station or Drive → opens automatically.

Also directly from the mobile apps, with reduced functionality.

Annotations

Toolbar in the PDF Viewer:

• Highlight: select text → marker icon → yellow highlighting
• Note: click a spot → note icon → enter text
• Stamp: predefined stamps (“Approved”, “Confidential”, “Draft”)
• Drawing: freehand with the mouse

Annotations are saved in the PDF (as an additional layer). They survive opening the file with Adobe Reader / other PDF viewers.

Use cases

• Review and comment on contracts
• Check invoices
• Read reports with highlights
• Fill in form PDFs without a local Adobe install

Creating PDFs

There’s no PDF creation directly in DSM. Instead:

• Synology Office (in Drive): create a Word document → export as PDF
• Locally: “Print → Save as PDF” from any program

Then upload the PDF files to storageDRIVE.

Full-text search — what gets indexed, what doesn’t

The DSM full-text search (Universal Search) indexes text-based files: Office documents, text PDFs, .txt, .md and so on. Their content is findable through search.

What it can’t do: OCR. Scanned PDFs and photos of documents are just images to the index — their text isn’t recognized. If you want scanned paperwork to be searchable, you have to OCR it locally before uploading — e.g. with the scanner app on your smartphone (many add a text layer), Adobe Acrobat, or the free ocrmypdf. Once a text layer is in place, the content lands in the search index like anything else.

Indexing new files takes a while with large volumes — that runs server-side in the background.

Both together — a typical workflow

Example “tax documents”:

1. The tax assessment arrives as a PDF — filed in Drive
2. Open it in the PDF Viewer, highlight the important parts
3. Your own notes in Note Station with references to the PDF
4. A code snippet for a tax script? Into the Text Editor
5. Everything in Drive — searchable via full text

Frequently asked questions

Are the annotations compatible with Adobe Reader? Yes, PDF annotations are a standard. Whoever opens the PDF with Adobe or Foxit sees your highlights.

Can I sign PDF files? To a limited extent. The PDF Viewer can insert signature images, but can’t create cryptographically signed PDFs. For legally binding signatures: local tools like Adobe Acrobat or DocuSign.

Text Editor with Markdown preview? Limited. Markdown is displayed with syntax highlighting, but there’s no live preview. For Markdown editing with preview: local tools (Obsidian, Typora) with sync via Drive.

Code files in the Text Editor — where’s the version history? Drive does automatic versioning. In the Drive browser: right-click the file → Version history.

Can we exclude certain code files from Drive indexing (e.g. node_modules)? There’s a global ignore list in the Drive settings. We configure it on request — open a ticket.

What if I want to use VS Code, but the files live in the cloud? Drive client locally with a sync folder → VS Code opens the local folder. Like a normal project, with cloud backup.

PDF size limit for viewing? Up to ~100 MB it runs smoothly. Above that it gets sluggish. Very large PDFs are better viewed locally.

Does the Text Editor work in a mobile browser? Yes, but it’s unwieldy. Typing on the virtual keyboard is tedious. For mobile notes: Note Station, not the Text Editor.

What’s next

• File Station
• Synology Drive browser
• Note Station