Merge branch 'master' into tests

Author: samuelhwilliams

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,38 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [master]
+  schedule:
+    - cron: '0 11 * * 0'
+
+jobs:
+  analyse:
+    name: Analyse
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        # We must fetch at least the immediate parents so that if this is
+        # a pull request then we can checkout the head.
+        fetch-depth: 2
+
+    # If this run was triggered by a pull request event, then checkout
+    # the head of the pull request instead of the merge commit.
+    - run: git checkout HEAD^2
+      if: ${{ github.event_name == 'pull_request' }}
+
+    # Initializes the CodeQL tools for scanning.
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      # Override language selection by uncommenting this and choosing your languages
+      with:
+        languages: javascript, python
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1

eel/__init__.py

@@ -1,4 +1,5 @@
 from builtins import range
+import traceback
 from io import open
 
 from gevent.threading import Timer
@@ -262,16 +263,32 @@ def _repeated_send(ws, msg):
 
 def _process_message(message, ws):
     if 'call' in message:
-        return_val = _exposed_functions[message['name']](*message['args'])
+        error_info = {}
+        try:
+            return_val = _exposed_functions[message['name']](*message['args'])
+            status = 'ok'
+        except Exception as e:
+            err_traceback = traceback.format_exc()
+            traceback.print_exc()
+            return_val = None
+            status = 'error'
+            error_info['errorText'] = repr(e)
+            error_info['errorTraceback'] = err_traceback
         _repeated_send(ws, _safe_json({ 'return': message['call'],
-                                        'value': return_val  }))
+                                        'status': status,
+                                        'value': return_val,
+                                        'error': error_info,}))
     elif 'return' in message:
         call_id = message['return']
         if call_id in _call_return_callbacks:
-            callback = _call_return_callbacks.pop(call_id)
-            callback(message['value'])
+            callback, error_callback = _call_return_callbacks.pop(call_id)
+            if message['status'] == 'ok':
+                callback(message['value'])
+            elif message['status'] == 'error' and error_callback is not None:
+                error_callback(message['error'], message['stack'])
         else:
             _call_return_values[call_id] = message['value']
+
     else:
         print('Invalid message received: ', message)
 
@@ -316,9 +333,9 @@ def _call_return(call):
     global _js_result_timeout
     call_id = call['call']
 
-    def return_func(callback=None):
+    def return_func(callback=None, error_callback=None):
         if callback is not None:
-            _call_return_callbacks[call_id] = callback
+            _call_return_callbacks[call_id] = (callback, error_callback)
         else:
             for w in range(_js_result_timeout):
                 if call_id in _call_return_values:

eel/eel.js

@@ -76,10 +76,10 @@ eel = {
     _call_return: function(call) {
         return function(callback = null) {
             if(callback != null) {
-                eel._call_return_callbacks[call.call] = callback;
+                eel._call_return_callbacks[call.call] = {resolve: callback};
             } else {
-                return new Promise(function(resolve) {
-                    eel._call_return_callbacks[call.call] = resolve;
+                return new Promise(function(resolve, reject) {
+                    eel._call_return_callbacks[call.call] = {resolve: resolve, reject: reject};
                 });
             }
         }
@@ -131,13 +131,27 @@ eel = {
                 if(message.hasOwnProperty('call') ) {
                     // Python making a function call into us
                     if(message.name in eel._exposed_functions) {
-                        let return_val = eel._exposed_functions[message.name](...message.args);
-                        eel._websocket.send(eel._toJSON({'return': message.call, 'value': return_val}));
+                        try {
+                            let return_val = eel._exposed_functions[message.name](...message.args);
+                            eel._websocket.send(eel._toJSON({'return': message.call, 'status':'ok', 'value': return_val}));
+                        } catch(err) {
+                            debugger
+                            eel._websocket.send(eel._toJSON(
+                                {'return': message.call,
+                                'status':'error',
+                                'error': err.message,
+                                'stack': err.stack}));
+                        }
                     }
                 } else if(message.hasOwnProperty('return')) {
                     // Python returning a value to us
                     if(message['return'] in eel._call_return_callbacks) {
-                        eel._call_return_callbacks[message['return']](message.value);
+                        if(message['status']==='ok'){
+                            eel._call_return_callbacks[message['return']].resolve(message.value);
+                        }
+                        else if(message['status']==='error' &&  eel._call_return_callbacks[message['return']].reject) {
+                                eel._call_return_callbacks[message['return']].reject(message['error']);
+                        }
                     }
                 } else {
                     throw 'Invalid message ' + message;
@@ -146,7 +160,7 @@ eel = {
             };
         });
     }
-}
+};
 
 eel._init();
 

examples/02 - callbacks/callbacks.py

@@ -7,13 +7,31 @@
 def py_random():
     return random.random()
 
+@eel.expose
+def py_exception(error):
+    if error:
+        raise ValueError("Test")
+    else:
+        return "No Error"
+
 def print_num(n):
     print('Got this from Javascript:', n)
 
+
+def print_num_failed(error, stack):
+    print("This is an example of what javascript errors would look like:")
+    print("\tError: ", error)
+    print("\tStack: ", stack)
+
 # Call Javascript function, and pass explicit callback function    
 eel.js_random()(print_num)
 
 # Do the same with an inline callback
 eel.js_random()(lambda n: print('Got this from Javascript:', n))
 
+# Show error handling
+eel.js_with_error()(print_num, print_num_failed)
+
+
 eel.start('callbacks.html', size=(400, 300))
+

examples/02 - callbacks/web/callbacks.html

@@ -10,6 +10,12 @@
         function js_random() {
             return Math.random();
         }
+
+        eel.expose(js_with_error);
+        function js_with_error() {
+            var test = 0;
+            test.something("does not exist");
+        }
 
         function print_num(n) {
             console.log('Got this from Python: ' + n);
@@ -20,7 +26,25 @@
 
         // Do the same with an inline callback
         eel.py_random()(n => console.log('Got this from Python: ' + n));
-        
+
+        // show usage with promises
+        // show no error
+        eel.py_exception(false)().then((result) => {
+                // this will execute since we said no error
+                console.log("No Error")
+            }).catch((result) => {
+                console.log("This won't be seen if no error")
+            }
+        );
+        // show if an error occurrs
+        eel.py_exception(true)().then((result) => {
+                // this will not execute
+                console.log("No Error")
+            }).catch((result) => {
+                console.log("This is the repr(e) for an exception " + result.errorText);
+                console.log("This is the full traceback:\n" + result.errorTraceback);
+            }
+        )
         </script>
     </head>