Web: add haloGetDefaultMethod() and report the current method in statusCallback() (#192)

docs/api-utils.md

@@ -45,7 +45,7 @@ haloConvertSignature(digest, derSignature, publicKey);
 
 **Example usage:**
 ```javascript
-import {haloConvertSignature} from '@arx-research/libhalo';
+import {execHaloCmdWeb, haloConvertSignature} from '@arx-research/libhalo';
 
 const KEY_NO = 1;
 
@@ -101,7 +101,7 @@ haloRecoverPublicKey(digest, derSignature);
 
 **Example usage:**
 ```javascript
-import {haloRecoverPublicKey} from '@arx-research/libhalo';
+import {execHaloCmdWeb, haloRecoverPublicKey} from '@arx-research/libhalo';
 
 const KEY_NO = 1;
 
@@ -132,3 +132,26 @@ haloRecoverPublicKey(
   '04e2b8ec92be2ed99962470555b31f094a1862d7fa3fb8a5de1f4d7f475bd93ffb27d7295e94ac11e8fa67b70582df375fc660c5e36078e83f7a1e9f7e6ae08142' 
 ]
 ```
+
+## haloGetDefaultMethod
+
+For websites: detect the best command execution method for the current device.
+Returns a string that could be passed directly as `options.method` key for `execHaloCmdWeb()` function.
+
+```javascript
+haloGetDefaultMethod();
+```
+
+**Example usage:**
+```
+import {execHaloCmdWeb, haloGetDefaultMethod} from '@arx-research/libhalo';
+
+let signRes = await execHaloCmdWeb({
+    "name": "sign",
+    "message": "010203",
+    "keyNo": 1,
+    "legacySignCommand": true
+}, {
+    "method": haloGetDefaultMethod()
+});
+```

docs/api-web.md

@@ -67,7 +67,7 @@ the command execution process is ongoing. This could be used to increase user's
 
 Example callback:
 ```
-statusCallback: (cause) => console.log(cause)
+statusCallback: (cause, execMethod) => console.log(cause, execMethod)
 ```
 
 The callback could be called with the following `cause` as a first argument:
@@ -80,6 +80,14 @@ The callback could be called with the following `cause` as a first argument:
   the library is postprocessing the result, the frontend should ask the user to untap the tag
   and wait a moment until the operation is completed;
 
+The `execMethod` will be either:
+
+* `credential` - if the credential prompt method is being used in order to scan the tag (mostly on iOS/Windows);
+* `webnfc` - if the WebNFC method is used in order to scan the tag (mostly on Android);
+
+The application's frontend could differentiate the UI behavior depending on the `execMethod` that is being used
+by the library in order to provide better user experience.
+
 #### options.debugCallback
 ```
 options.debugCallback: null/function

drivers/common.js

@@ -20,6 +20,10 @@ const {ERROR_CODES} = require("../halo/errors");
 
 let isCallRunning = null;
 
+/**
+ * Detect the best command execution method for the current device.
+ * @returns {string} Either "credential" or "webnfc".
+ */
 function detectMethod() {
     try {
         new NDEFReader();
@@ -137,5 +141,6 @@ async function execHaloCmdWeb(command, options) {
 module.exports = {
     execHaloCmdWeb,
     execHaloCmd,
-    checkErrors
+    checkErrors,
+    detectMethod
 };

drivers/credential.js

@@ -53,7 +53,7 @@ async function execCredential(request, options) {
 
     let u2fRes;
 
-    options.statusCallback("init", "get-credential");
+    options.statusCallback("init", "credential", "get-credential");
     options.debugCallback("get-credential");
 
     try {
@@ -66,7 +66,7 @@ async function execCredential(request, options) {
         }
     }
 
-    options.statusCallback("scanned", "get-credential-done");
+    options.statusCallback("scanned", "credential", "get-credential-done");
     options.debugCallback("get-credential-done");
 
     let res = u2fRes.response.signature;

drivers/webnfc.js

@@ -58,9 +58,9 @@ async function execWebNFC(request, options) {
             options.debugCallback(writeStatus);
 
             if (writeStatus === "nfc-write") {
-                options.statusCallback("init", "nfc-write");
+                options.statusCallback("init", "webnfc", "nfc-write");
             } else if (writeStatus === "nfc-write-error") {
-                options.statusCallback("retry", "nfc-write-error");
+                options.statusCallback("retry", "webnfc", "nfc-write-error");
             }
 
             await ndef.write({records: [{recordType: "unknown", data: request}]});
@@ -83,7 +83,7 @@ async function execWebNFC(request, options) {
     return new Promise((resolve, reject) => {
         ndef.onreadingerror = (event) => {
             options.debugCallback("nfc-read-error");
-            options.statusCallback("retry", "nfc-read-error");
+            options.statusCallback("retry", "webnfc", "nfc-read-error");
         };
 
         ndef.onreading = (event) => {
@@ -114,7 +114,7 @@ async function execWebNFC(request, options) {
                 }
 
                 options.debugCallback("nfc-success");
-                options.statusCallback("scanned", "nfc-success");
+                options.statusCallback("scanned", "webnfc", "nfc-success");
 
                 ndef.onreading = () => null;
                 ndef.onreadingerror = () => null;
@@ -129,7 +129,7 @@ async function execWebNFC(request, options) {
                 }, 1);
             } catch (e) {
                 options.debugCallback("nfc-parse-error");
-                options.statusCallback("retry", "nfc-parse-error");
+                options.statusCallback("retry", "webnfc", "nfc-parse-error");
             }
         };
     });

web/examples/demo.html

@@ -76,10 +76,12 @@
             // all options are optional, you can use them to increase user's experience
             let options = {
                 method: method,
-                statusCallback: (cause) => {
+                statusCallback: (cause, execMethod) => {
                     if (cause === "init") {
                         // explicitly ask the user to tap the tag
-                        document.getElementById('statusText').innerText = 'Tap the tag to the back of your smartphone and hold it for a while.';
+                        document.getElementById('statusText').innerText =
+                            'Tap the tag to the back of your smartphone and hold it for a while. ' +
+                            'Using execution method: ' + execMethod;
                     } else if (cause === "retry") {
                         // this callback is invoked when there is a communication error
                         // the executeNFCCommand() call will be still running and the frontend

web/weblib.js

@@ -5,7 +5,7 @@
  */
 
 const {
-    execHaloCmdWeb
+    execHaloCmdWeb, detectMethod
 } = require("../drivers/common");
 const {
     HaloTagError,
@@ -34,6 +34,7 @@ module.exports = {
     // for web usage
     execHaloCmdWeb,
     haloFindBridge,
+    haloGetDefaultMethod: detectMethod,
 
     // for bridge demo
     haloCreateWs,