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

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