---

name: add-pdf-viewer description: Internal implementation skill invoked by /add-native for native PDF control workflows. Handles HTTPS and file URI PDF viewing with @microsoft/power-apps-native-pdf-viewer 0.2.9+. user-invocable: false disable-model-invocation: true allowed-tools: Read, Edit, Write, Grep, Glob, Bash, AskUserQuestion model: sonnet

📋 Shared instructions: shared-instructions.md — read first.

Add PDF Viewer

Internal helper. Users should invoke /add-native pdf-viewer, /add-native pdf-control, or /add-native @microsoft/power-apps-native-pdf-viewer; /add-native routes here after resolving the capability.

Generate or verify the native PDF viewer wrapper and show how to call its native React Native API. Version 0.2.9 and later support HTTPS PDF URLs and local file:// URIs. Do not use the HostingSDK / PCF path from the package README; that is for a different use case.

Steps

1. Verify app

test -f app.config.js && test -f power.config.json && test -f package.json && test -d src

If this fails, tell the user to run /create-mobile-app first and STOP.

2. Verify package is already present

node -e "const p=require('./package.json'); const m='@microsoft/power-apps-native-pdf-viewer'; if (!p.dependencies?.[m]) { console.error('MISSING: ' + m + ' is not in package.json. The template/app must already ship this native extension. This skill will not install it or edit native config.'); process.exit(1); } let v; try { v=require('./node_modules/' + m + '/package.json').version; } catch { console.error('MISSING_INSTALL: cannot verify the installed ' + m + ' version. Run the project package install first.'); process.exit(1); } const [major,minor,patch]=v.split('.').map(Number); if (!(major > 0 || minor > 2 || (minor === 2 && patch >= 9))) { console.error('UNSUPPORTED_VERSION: ' + m + ' ' + v + ' does not support file:// URIs. Version 0.2.9+ is required.'); process.exit(1); } console.log('OK: native PDF viewer ' + v + ' supports https:// and file://');"

If the check fails, STOP. Do not run npm install, npx expo install, pod install, or edit app.config.js. Version 0.2.9+ must already be part of the app's native build.

3. Write or verify src/native/pdfViewer.ts

Create src/native/pdfViewer.ts if it does not exist. If it already exists, inspect it and patch only if it violates the supported URI rules or throws instead of returning a result.

The wrapper MUST:

• Accept https:// URLs and file:// URIs.
• Reject content://, blob:, http://, empty, and malformed URLs before calling native code.
• Return a discriminated union and never throw.
• Return NATIVE_MODULE_MISSING when the extension is installed in JS but unavailable in the native build.
• Surface viewer action results (shared, printed, dismissed) when available.
• Return VIEWER_FAILED for native errors not covered by validation/module checks.

// src/native/pdfViewer.ts
import { NativePdfViewer } from '@microsoft/power-apps-native-pdf-viewer';

export type PdfViewerResult =
  | { ok: true; action?: 'shared' | 'printed' | 'dismissed' }
  | { ok: false; reason: 'INVALID_URL' | 'NATIVE_MODULE_MISSING' | 'VIEWER_FAILED'; message?: string };

export async function openHttpsPdf(
  url: string,
  options?: { title?: string; maxFileSizeMb?: number; cacheEnabled?: boolean },
): Promise<PdfViewerResult> {
  let parsed: URL;
  try {
    parsed = new URL(url);
  } catch {
    return { ok: false, reason: 'INVALID_URL', message: 'PDF location must be a valid https:// URL or file:// URI.' };
  }

  const isHttpsUrl = parsed.protocol === 'https:';
  const isFileUri = parsed.protocol === 'file:' && url.startsWith('file://') && parsed.pathname !== '/';
  if (!isHttpsUrl && !isFileUri) {
    return { ok: false, reason: 'INVALID_URL', message: 'Native PDF viewer supports https:// and file:// inputs only.' };
  }

  if (!NativePdfViewer?.openPdf) {
    return { ok: false, reason: 'NATIVE_MODULE_MISSING', message: 'Native PDF viewer module is not available in this build.' };
  }

  try {
    const response = await NativePdfViewer.openPdf(url, {
      maxFileSizeMb: 50,
      cacheEnabled: true,
      ...options,
    });

    if (response.status === 'ok') {
      return { ok: true, action: response.result?.action };
    }

    return { ok: false, reason: 'VIEWER_FAILED', message: response.message ?? response.error };
  } catch (error: any) {
    return { ok: false, reason: 'VIEWER_FAILED', message: error?.message ?? String(error) };
  }
}

4. Use the wrapper

Screens import the wrapper, not the native package directly:

import { openHttpsPdf } from '@/native/pdfViewer';

const response = await openHttpsPdf('https://example.com/report.pdf', {
  title: "Inspection report",
});

if (response.ok) {
  switch (response.action) {
    case "shared":
      // User completed native Share.
      break;
    case "printed":
      // User completed native Print.
      break;
    case "dismissed":
      // User closed the viewer.
      break;
  }
} else {
  console.warn("Failed to open PDF:", response.reason, response.message);
}

Notes:

• URLs must use https:// or a non-empty file:// URI. content://, blob:, and http:// are not supported by this skill.
• Use @microsoft/power-apps-native-pdf-viewer only for this native PDF viewing use case.
• Use expo-document-picker for picking/importing/uploading a local PDF or document.
• Use /add-native pdf-report for generated local PDFs. That helper requires expo-print and adds sharing behavior only when expo-sharing is already present.
• Generated local PDFs from expo-print may be opened by native PDF viewer 0.2.9+ as file:// URIs.
• Share and Print are built into the native viewer; there are no separate JS share/print calls.
• The wrapper returns { ok: true } | { ok: false }; handle every non-ok reason in UI.

5. Type-check

npx tsc --noEmit

Fix any TypeScript errors before rebuilding.

6. Native rebuild note

This skill does not install native code. If the package was just added outside the skill, the app needs a native rebuild outside this workflow. If the package was already in the build, Metro hot reload is enough for wrapper edits.

7. Do not use HostingSDK / PCF

Do not import or register:

import NativePdfViewerExtension from "@microsoft/power-apps-native-pdf-viewer";

Do not wire Companion PCF or NativePdfViewerExtension. In Power Apps native code apps, use the native React Native API above.

8. Summary

Tell the user:

PDF viewer added
Package present   : @microsoft/power-apps-native-pdf-viewer
Wrapper           : src/native/pdfViewer.ts
URL support       : HTTPS and file:// (0.2.9+)
Type-check        : PASS
Native rebuild    : not performed by this skill
Usage             : openHttpsPdf(...)
HostingSDK / PCF  : not used

Update memory-bank.md under Controls:

- PDF viewer added — @microsoft/power-apps-native-pdf-viewer (<ISO date>)