tauri_plugin_nfc/lib.rs
1// Copyright 2019-2023 Tauri Programme within The Commons Conservancy
2// SPDX-License-Identifier: Apache-2.0
3// SPDX-License-Identifier: MIT
4
5//! Read and write NFC tags on Android and iOS.
6//!
7//! This plugin is mobile only: the whole crate is gated behind `#[cfg(mobile)]`,
8//! so it expands to nothing when compiling for Linux, macOS or Windows.
9//!
10//! Register the plugin with `init` and use the `NfcExt` trait to reach the
11//! `Nfc` instance from any `tauri::Manager` implementation (the app handle, a window, ...).
12
13#![cfg(mobile)]
14
15use serde::{Deserialize, Serialize};
16use tauri::{
17 Manager, Runtime,
18 plugin::{Builder, PluginHandle, TauriPlugin},
19};
20
21pub use models::*;
22
23mod error;
24mod models;
25
26pub use error::{Error, Result};
27
28#[cfg(target_os = "android")]
29const PLUGIN_IDENTIFIER: &str = "app.tauri.nfc";
30
31#[cfg(target_os = "ios")]
32tauri::ios_plugin_binding!(init_plugin_nfc);
33
34/// Access to the nfc APIs.
35pub struct Nfc<R: Runtime>(PluginHandle<R>);
36
37#[derive(Deserialize)]
38struct IsAvailableResponse {
39 available: bool,
40}
41
42#[derive(Serialize)]
43struct WriteRequest {
44 records: Vec<NfcRecord>,
45}
46
47impl<R: Runtime> Nfc<R> {
48 /// Checks whether NFC is supported by the device and currently usable by the app.
49 ///
50 /// On Android this is `false` when the device has no NFC adapter or when NFC is
51 /// disabled in the device settings.
52 /// On iOS this is `false` when the `NFCReaderUsageDescription` entry is missing from the
53 /// `Info.plist` file or when NFC tag reading is not available on the device.
54 pub fn is_available(&self) -> crate::Result<bool> {
55 self.0
56 .run_mobile_plugin::<IsAvailableResponse>("isAvailable", ())
57 .map(|r| r.available)
58 .map_err(Into::into)
59 }
60
61 /// Scans an NFC tag, blocking until a tag matching the given [`ScanRequest::kind`] filters
62 /// is read or the scan fails.
63 ///
64 /// Set [`ScanRequest::keep_session_alive`] to `true` to keep the connection to the tag open
65 /// after it has been scanned, so that a following [`Self::write`] call writes to that tag.
66 ///
67 /// # Errors
68 ///
69 /// Returns an error when NFC is not available (see [`Self::is_available`])
70 /// or when the tag could not be read.
71 pub fn scan(&self, payload: ScanRequest) -> crate::Result<ScanResponse> {
72 self.0
73 .run_mobile_plugin("scan", payload)
74 .map(|v| ScanResponse { tag: v })
75 .map_err(Into::into)
76 }
77
78 /// Writes the given NDEF records to an NFC tag, blocking until the write completes or fails.
79 ///
80 /// Because this API does not take a scan kind, on Android it can only write to the tag of an
81 /// ongoing session, so it must be preceded by a [`Self::scan`] call with
82 /// [`ScanRequest::keep_session_alive`] set to `true`.
83 /// On iOS an NDEF reader session is started when there is no ongoing session, and the
84 /// records are written to the first tag that is scanned.
85 ///
86 /// # Errors
87 ///
88 /// Returns an error when NFC is not available (see [`Self::is_available`]), when there is no
89 /// connected tag on Android, when the tag is read-only, when it cannot hold the message or
90 /// when it does not support the NDEF format.
91 pub fn write(&self, records: Vec<NfcRecord>) -> crate::Result<()> {
92 self.0
93 .run_mobile_plugin("write", WriteRequest { records })
94 .map_err(Into::into)
95 }
96}
97
98/// Extensions to [`tauri::App`], [`tauri::AppHandle`], [`tauri::WebviewWindow`], [`tauri::Webview`] and [`tauri::Window`] to access the NFC APIs.
99pub trait NfcExt<R: Runtime> {
100 /// Returns the [`Nfc`] instance managed by the plugin.
101 fn nfc(&self) -> &Nfc<R>;
102}
103
104impl<R: Runtime, T: Manager<R>> crate::NfcExt<R> for T {
105 fn nfc(&self) -> &Nfc<R> {
106 self.state::<Nfc<R>>().inner()
107 }
108}
109
110/// Initializes the plugin.
111pub fn init<R: Runtime>() -> TauriPlugin<R> {
112 Builder::new("nfc")
113 .setup(|app, api| {
114 #[cfg(target_os = "android")]
115 let handle = api.register_android_plugin(PLUGIN_IDENTIFIER, "NfcPlugin")?;
116 #[cfg(target_os = "ios")]
117 let handle = api.register_ios_plugin(init_plugin_nfc)?;
118 app.manage(Nfc(handle));
119 Ok(())
120 })
121 .build()
122}