chatboxai/chatbox · error · Error

Preview not available

Error message

Preview not available

What it means

Thrown by readSandboxHtml (src/renderer/modals/ArtifactPreview.tsx:39) when the current platform has not implemented the optional platform.sandboxReadFileBase64 capability. The function is called from onPublish when publishing a sandboxed HTML artifact that has no inline htmlCode. Because sandbox reading is an optional platform interface method (see platform/interfaces.ts), platforms/shells that omit it cannot publish sandbox-only artifacts and hit this guard before any I/O.

Source

Thrown at src/renderer/modals/ArtifactPreview.tsx:39

import * as toastActions from '@/stores/toastActions'

export interface ArtifactPreviewProps {
  htmlCode: string
  previewUrl?: string
  sandboxPath?: string
  uniqueId?: string
  sessionId?: string
}

function decodeBase64Utf8(base64: string): string {
  const binary = atob(base64)
  const bytes = Uint8Array.from(binary, (char) => char.charCodeAt(0))
  return new TextDecoder().decode(bytes)
}

async function readSandboxHtml(sandboxPath: string): Promise<string> {
  if (!platform.sandboxReadFileBase64) {
    throw new Error('Preview not available')
  }
  const res = await platform.sandboxReadFileBase64({ filePath: sandboxPath })
  if (!res.success || !res.base64) {
    throw new Error(res.error || 'Preview not available')
  }
  return inlineSandboxHtmlAssets(decodeBase64Utf8(res.base64), sandboxPath, (assetPath) => {
    if (!platform.sandboxReadFileBase64) {
      return Promise.resolve({ success: false })
    }
    return platform.sandboxReadFileBase64({ filePath: assetPath })
  })
}

const ArtifactPreview = NiceModal.create((props: ArtifactPreviewProps) => {
  const { htmlCode, previewUrl, sandboxPath, uniqueId, sessionId } = props
  const modal = useModal()
  const { t } = useTranslation()
  const [reloadSign, setReloadSign] = useState(0)

View on GitHub (pinned to 81571269ad)

Solutions

  1. Disable or hide the Publish action on platforms without platform.sandboxReadFileBase64 (guard canPublish on the capability, not just on sandboxPath).
  2. Ensure the artifact carries inline htmlCode so publish does not depend on reading the sandbox.
  3. If you maintain a platform adapter, implement sandboxReadFileBase64 to read files from the sandbox and return { success, base64 }.
  4. Catch the error and show a clear 'publish not supported on this device' message rather than a generic failure.

Example fix

// before
const canPublish = htmlCode.trim().length > 0 || !!sandboxPath

// after (only offer sandbox-backed publish where the capability exists)
const canPublish =
  htmlCode.trim().length > 0 || (!!sandboxPath && !!platform.sandboxReadFileBase64)
Defensive patterns

Strategy: validation

Validate before calling

// Gate publish on the capability, not just on having a sandbox path
const canPublish =
  htmlCode.trim().length > 0 || (!!sandboxPath && !!platform.sandboxReadFileBase64)

Type guard

// Narrow the optional platform capability before calling
function canReadSandbox(
  p: { sandboxReadFileBase64?: (...a: any[]) => any }
): p is { sandboxReadFileBase64: (params: { filePath: string }) => Promise<{ success: boolean; base64?: string; error?: string }> } {
  return typeof p.sandboxReadFileBase64 === 'function'
}

Try / catch

// onPublish already catches; keep the capability guard to avoid offering publish
try {
  const html = htmlCode.trim() ? htmlCode : await readSandboxHtml(sandboxPath || '')
} catch (e) {
  toastActions.add((e as Error)?.message || t('Publish failed'))
}

Prevention

When it happens

Trigger: ArtifactPreview.onPublish is invoked with an artifact whose htmlCode is empty but sandboxPath is set (canPublish true via sandboxPath), so readSandboxHtml(sandboxPath) runs. On a platform where platform.sandboxReadFileBase64 is undefined, the very first check throws 'Preview not available'. The publish then fails and the catch at line 83 shows a toast.

Common situations: Running the app on a platform variant that did not wire up sandbox file access (some mobile/embedded shells); a new target platform that reuses the renderer but not the desktop platform implementation; opening a shared/synced artifact whose source is only in the sandbox on a platform without sandbox support.

Related errors

AI-assisted analysis of chatboxai/chatbox@81571269ad (2026-08-12). Data as JSON: /api/errors/e2fe9631a1bf5bf6. Report an issue: GitHub.