Expo Document Picker

import { getDocumentAsync } from "expo-document-picker";

import { 
  getDocumentAsync,
  DocumentPickerOptions,
  DocumentPickerResult,
  DocumentPickerAsset,
  DocumentPickerSuccessResult,
  DocumentPickerCanceledResult
} from "expo-document-picker";

const { getDocumentAsync } = require("expo-document-picker");

import { getDocumentAsync } from "expo-document-picker";

// Simple document picking
const result = await getDocumentAsync();

if (!result.canceled) {
  console.log("Selected document:", result.assets[0].name);
  console.log("Document URI:", result.assets[0].uri);
}

// Pick specific file types
const pdfResult = await getDocumentAsync({
  type: "application/pdf",
});

// Pick multiple files
const multipleResult = await getDocumentAsync({
  type: ["image/*", "application/pdf"],
  multiple: true,
});

/**
 * Display the system UI for choosing a document. By default, the chosen file is copied to the app's internal cache directory.
 * > **Notes for Web:** The system UI can only be shown after user activation (e.g. a `Button` press).
 * > Therefore, calling `getDocumentAsync` in `componentDidMount`, for example, will **not** work as
 * > intended. The `cancel` event will not be returned in the browser due to platform restrictions and
 * > inconsistencies across browsers.
 *
 * @param options - Configuration options for document selection
 * @returns Promise resolving to DocumentPickerResult
 *
 * If the user cancelled the document picking, the promise resolves to `{ canceled: true, assets: null }`.
 */
function getDocumentAsync(options?: DocumentPickerOptions): Promise<DocumentPickerResult>;

interface DocumentPickerOptions {
  /** MIME type(s) of documents available to be picked. Supports wildcards like 'image/*'. Default: '*/*' */
  type?: string | string[];
  /** If true, picked file is copied to cache directory for immediate access. iOS/Android only. Default: true */
  copyToCacheDirectory?: boolean;
  /** Allows multiple files to be selected. Default: false */
  multiple?: boolean;
  /** If true, asset url is base64 encoded from the file. Web only. Default: true */
  base64?: boolean;
}

/** Result type for successful or canceled document pick operations */
type DocumentPickerResult = DocumentPickerSuccessResult | DocumentPickerCanceledResult;

/** Result when documents are successfully picked */
interface DocumentPickerSuccessResult {
  /** Always false when documents are picked */
  canceled: false;
  /** Array of picked document assets */
  assets: DocumentPickerAsset[];
  /** FileList object for web platform parity */
  output?: FileList;
}

/** Result when document picking is canceled */
interface DocumentPickerCanceledResult {
  /** Always true when canceled */
  canceled: true;
  /** Always null when canceled */
  assets: null;
  /** Always null when canceled (web only) */
  output?: null;
}

/** Represents a selected document asset */
interface DocumentPickerAsset {
  /** Document original name */
  name: string;
  /** Document size in bytes */
  size?: number;
  /** URI to the local document file */
  uri: string;
  /** Document MIME type */
  mimeType?: string;
  /** Timestamp of last document modification (milliseconds since Unix epoch) */
  lastModified: number;
  /** File object for web platform parity */
  file?: File;
  /** Base64 string of the file (web only) */
  base64?: string;
}

// Pick only PDF files
const pdfResult = await getDocumentAsync({
  type: "application/pdf",
});

// Pick images or documents
const mediaResult = await getDocumentAsync({
  type: ["image/*", "application/pdf", "text/plain"],
});

const multipleFiles = await getDocumentAsync({
  type: "*/*",
  multiple: true,
});

if (!multipleFiles.canceled) {
  multipleFiles.assets.forEach((asset, index) => {
    console.log(`File ${index + 1}: ${asset.name}`);
    console.log(`Size: ${asset.size} bytes`);
    console.log(`Type: ${asset.mimeType}`);
  });
}

// Get base64 data for web usage
const webResult = await getDocumentAsync({
  type: "image/*",
  base64: true, // Default on web
});

if (!webResult.canceled && webResult.assets[0].base64) {
  // Use base64 data directly
  const imageData = webResult.assets[0].base64;
  // Can be used in img src or uploaded to server
}

const result = await getDocumentAsync();

if (result.canceled) {
  console.log("User canceled document selection");
} else {
  // Process selected documents
  const selectedFile = result.assets[0];
  console.log("Selected:", selectedFile.name);
  console.log("URI:", selectedFile.uri);
  console.log("Size:", selectedFile.size);
  console.log("Type:", selectedFile.mimeType);
  console.log("Modified:", new Date(selectedFile.lastModified));
}