Document picker

The options are the module's own, passed through unchanged. A canceled picker answers with no files rather than a result to unwrap, and the system picker needs no permission, so none is asked for.

Install

npx expo install expo-document-picker

import { DocumentPicker } from '@ng-native/expo/document-picker';

The smallest useful example

import { Component, inject, signal } from '@angular/core';
import { Pressable, Text } from '@ng-native/components';
import { DocumentPicker } from '@ng-native/expo/document-picker';

@Component({
  selector: 'app-attach',
  imports: [Pressable, Text],
  template: `
    <pressable (press)="attach()"><text>Attach a PDF</text></pressable>
    <text>{{ attached() }}</text>
  `,
})
export class Attach {
  private readonly documents = inject(DocumentPicker);
  protected readonly attached = signal('');

  protected async attach(): Promise<void> {
    const [file] = await this.documents.pick({ type: 'application/pdf' });
    if (file) this.attached.set(file.name);
  }
}

To read what was picked, open its uri with FileSystem: await this.files.file(file.uri).text(), with files = inject(FileSystem) as a field of the component, or .bytes() for anything that is not text.

What it does

• pick(options?) - opens the picker and resolves to the files chosen, empty if the user canceled. Each is the module's own DocumentPickerAsset: uri, name, mimeType, size and lastModified.
  • type - a MIME type such as 'image/*', or a list of them. Everything by default.
  • multiple - allow more than one file.
  • copyToCacheDirectory - on by default: each file is copied into the app's cache, so the file system and other Expo modules can read its uri. Off leaves the platform's own reference, which only some readers understand.
  • base64 - on the web, whether each uri is the file's contents as base64. On by default.

Without the module

On iOS and Android, a missing expo-document-picker - never installed, or installed without the app being rebuilt since - leaves the service made, so injecting it does not throw. A call, or a read of a value only the module knows, throws a MissingModuleError. Its message names the module and the commands that fix it; see Using a module.

On the web, and in a test that provides no fake, pick() resolves to an empty list.

Reference