Democr.ai Plugin Developer Docs

Attachment Preview

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Use AttachmentPreview only when a module explicitly chooses to render an attachment preview.

MessageList does not open this component automatically. Attachment clicks are application actions; the module receives the attachment payload and owns the next step.

Parameters

Property Web Desktop Runtime update Notes
id yes yes no Required
name yes yes practical no File name
mime yes yes practical no Drives preview branch
path yes yes practical no File source
source_path yes yes practical no File source
file_id no direct yes practical no Desktop consumes it directly
url yes yes practical no Preferred cross-client source
height yes yes practical no Preview height
style yes yes yes Wrapper styling

Cross-renderer rule:

  • Always provide url or source_path for previewable files.
  • Do not rely on file_id alone if the flow must also work on web.

Example

preview = sdk.ui.AttachmentPreview(
    "attachment_preview",
    name="candidate-brief.pdf",
    mime="application/pdf",
    source_path="/abs/path/candidate-brief.pdf",
    url="https://example.invalid/candidate-brief.pdf",
    height=420,
)

Attachment Click Flow

Recommended pattern:

  1. MessageList exposes on_attachment_click.
  2. Clicking an image or PDF emits an action with attachment context.
  3. The action decides what to do with that payload.
  4. If the module needs a preview, it explicitly renders AttachmentPreview or another dedicated content/document viewer.

Recommended action payload fields:

  • message_id
  • message_role
  • name
  • mime
  • path
  • source_path
  • file_id
  • url
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