create-file-viewer

Development

Create a custom file viewer for Datagrok file share browser

QUICK START

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Source SKILL.md: https://github.com/majiayu000/claude-skill-registry/blob/HEAD/skills/development/create-file-viewer/SKILL.md

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Create File Viewer

Create a custom file viewer that is used by the Datagrok file share browser to display files with specific extensions.

Usage

/create-file-viewer [extensions] [package-path]

Instructions

When this skill is invoked, help the user create a custom file viewer for one or more file extensions.

Step 1: Create the viewer function

Add a function to package.ts (or a separate file imported by it) with the correct annotations. The function must:

Accept a single file input
Return a view
Have the fileViewer tag plus a fileViewer-<ext> tag for each supported extension

//name: myFileViewer
//tags: fileViewer, fileViewer-xyz, fileViewer-abc
//input: file file
//output: view v
export function myFileViewer(file: DG.FileInfo) {
  let view = DG.View.create();

  // Read file content and render it
  file.readAsString().then((content) => {
    let host = ui.div([]);
    // Process and display content
    host.innerText = content;
    view.append(host);
  });

  return view;
}

Step 2: Handle file content

Choose the appropriate method to read file content:

file.readAsString() - for text-based files (returns Promise<string>)
file.readAsBytes() - for binary files (returns Promise<Uint8Array>)

Example for binary files:

//tags: fileViewer, fileViewer-mol, fileViewer-sdf, fileViewer-cif
//input: file file
//output: view v
export function structureViewer(file: DG.FileInfo) {
  let view = DG.View.create();
  let host = ui.div([], 'd4-ngl-viewer');

  file
    .readAsBytes()
    .then(bytes => {
      // Process binary content
      let blob = new Blob([bytes]);
      // Render blob...
    });

  view.append(host);
  return view;
}

Step 3: Build and publish

npm run build
grok publish

Once the package is published, Datagrok automatically uses the viewer when a user selects a file with a matching extension in the file share browser.

Key points

Each supported extension needs its own tag: fileViewer-mol, fileViewer-sdf, etc.
The function runs when a user clicks on a file with a matching extension in the file share browser
The view is displayed in the file preview panel
Return the view synchronously; load file content asynchronously inside it
Multiple extensions can be handled by a single function with multiple fileViewer-<ext> tags

Behavior

Ask the user which file extension(s) they want to support if not specified
Determine whether the file is text-based or binary to choose readAsString vs readAsBytes
Create the viewer function with correct tags for all specified extensions
Add rendering logic appropriate for the file type
Ensure imports are correct (import * as DG from 'datagrok-api/dg', import * as ui from 'datagrok-api/ui')