Widgets: Make a generic postMessage API in WidgetVC

It will be used for https://docs.google.com/document/d/1uPF7XWY_dXTKVKV7jZQ2KmsI19wn9-kFRgQ1tFQP7wQ/edit#. The Modular postMessage API becomes a specialisation of it.
2026-04-24 10:32:46 +02:00 · 2018-05-07 14:18:24 +02:00
parent 6a04301926
commit b1d7617d05
6 changed files with 276 additions and 209 deletions
@@ -16,6 +16,10 @@

 #import "WidgetViewController.h"

+#import "AppDelegate.h"
+
+NSString *const kJavascriptSendResponseToModular = @"riotIOS.sendResponse('%@', %@);";
+
@interface WidgetViewController ()
 {
    Widget  *widget;
@@ -42,7 +46,198 @@
    webView.scalesPageToFit = NO;
    webView.scrollView.bounces = NO;

-    self.navigationItem.title = widget.name;
+    // Disable opacity so that the webview background uses the current interface theme
+    webView.opaque = NO;
+
+    if (widget)
+    {
+        self.navigationItem.title = widget.name ? widget.name : widget.type;
+    }
+}
+
+- (void)showErrorAsAlert:(NSError*)error
+{
+    NSString *title = [error.userInfo valueForKey:NSLocalizedFailureReasonErrorKey];
+    NSString *msg = [error.userInfo valueForKey:NSLocalizedDescriptionKey];
+    if (!title)
+    {
+        if (msg)
+        {
+            title = msg;
+            msg = nil;
+        }
+        else
+        {
+            title = [NSBundle mxk_localizedStringForKey:@"error"];
+        }
+    }
+
+    __weak __typeof__(self) weakSelf = self;
+
+    UIAlertController *alert = [UIAlertController alertControllerWithTitle:title message:msg preferredStyle:UIAlertControllerStyleAlert];
+    [alert addAction:[UIAlertAction actionWithTitle:[NSBundle mxk_localizedStringForKey:@"ok"]
+                                              style:UIAlertActionStyleDefault
+                                            handler:^(UIAlertAction * action) {
+
+                                                typeof(self) self = weakSelf;
+
+                                                if (self)
+                                                {
+                                                    // Leave this widget VC
+                                                    [self withdrawViewControllerAnimated:YES completion:nil];
+                                                }
+
+                                            }]];
+
+    [self presentViewController:alert animated:YES completion:nil];
+}
+
+#pragma mark - UIWebViewDelegate
+
+-(void)webViewDidFinishLoad:(UIWebView *)theWebView
+{
+    [self enableDebug];
+
+    // Setup js code
+    NSString *path = [[NSBundle mainBundle] pathForResource:@"postMessageAPI" ofType:@"js"];
+    NSString *js = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
+    [webView stringByEvaluatingJavaScriptFromString:js];
+
+    [self stopActivityIndicator];
+
+    // Check connectivity
+    if ([AppDelegate theDelegate].isOffline)
+    {
+        // The web page may be in the cache, so its loading will be successful
+        // but we cannot go further, it often leads to a blank screen.
+        // So, display an error so that the user can escape.
+        NSError *error = [NSError errorWithDomain:NSURLErrorDomain
+                                             code:NSURLErrorNotConnectedToInternet
+                                         userInfo:@{
+                                                    NSLocalizedDescriptionKey : NSLocalizedStringFromTable(@"network_offline_prompt", @"Vector", nil)
+                                                    }];
+        [self showErrorAsAlert:error];
+    }
+}
+
+- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
+{
+    NSString *urlString = [[request URL] absoluteString];
+
+    if ([urlString hasPrefix:@"js:"])
+    {
+        // Listen only to scheme of the JS-UIWebView bridge
+        NSString *jsonString = [[[urlString componentsSeparatedByString:@"js:"] lastObject]  stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
+        NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];
+
+        NSError *error;
+        NSDictionary *parameters = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers
+                                                                     error:&error];
+        if (!error)
+        {
+            [self onMessage:parameters];
+        }
+
+        return NO;
+    }
+
+    if (navigationType == UIWebViewNavigationTypeLinkClicked )
+    {
+        // Open links outside the app
+        [[UIApplication sharedApplication] openURL:[request URL]];
+        return NO;
+    }
+
+    return YES;
+}
+
+- (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error
+{
+    // Filter out the users's scalar token
+    NSString *errorDescription = error.description;
+    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"scalar_token=\\w*"
+                                                                           options:NSRegularExpressionCaseInsensitive error:nil];
+    errorDescription = [regex stringByReplacingMatchesInString:errorDescription
+                                                       options:0
+                                                         range:NSMakeRange(0, errorDescription.length)
+                                                  withTemplate:@"scalar_token=..."];
+
+    NSLog(@"[WidgetVC] didFailLoadWithError: %@", errorDescription);
+
+    [self stopActivityIndicator];
+    [self showErrorAsAlert:error];
+}
+
+#pragma mark - postMessage API
+
+- (void)onMessage:(NSDictionary*)JSData
+{
+    // @TODO
+    NSDictionary *eventData;
+    MXJSONModelSetDictionary(eventData, JSData[@"event.data"]);
+}
+
+- (void)sendBoolResponse:(BOOL)response toEvent:(NSDictionary*)eventData
+{
+    // Convert BOOL to "true" or "false"
+    NSString *js = [NSString stringWithFormat:kJavascriptSendResponseToModular,
+                    eventData[@"_id"],
+                    response ? @"true" : @"false"];
+
+    [webView stringByEvaluatingJavaScriptFromString:js];
+}
+
+- (void)sendIntegerResponse:(NSUInteger)response toEvent:(NSDictionary*)eventData
+{
+    NSString *js = [NSString stringWithFormat:kJavascriptSendResponseToModular,
+                    eventData[@"_id"],
+                    @(response)];
+
+    [webView stringByEvaluatingJavaScriptFromString:js];
+}
+
+- (void)sendNSObjectResponse:(NSObject*)response toEvent:(NSDictionary*)eventData
+{
+    NSString *jsString;
+
+    if (response)
+    {
+        // Convert response into a JS object through a JSON string
+        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:response
+                                                           options:0
+                                                             error:0];
+        NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
+
+        jsString = [NSString stringWithFormat:@"JSON.parse('%@')", jsonString];
+    }
+    else
+    {
+        jsString = @"null";
+    }
+
+    NSString *js = [NSString stringWithFormat:kJavascriptSendResponseToModular,
+                    eventData[@"_id"],
+                    jsString];
+
+    [webView stringByEvaluatingJavaScriptFromString:js];
+}
+
+- (void)sendError:(NSString*)message toEvent:(NSDictionary*)eventData
+{
+    NSLog(@"[WidgetVC] sendError: Action %@ failed with message: %@", eventData[@"action"], message);
+
+    // TODO: JS has an additional optional parameter: nestedError
+    [self sendNSObjectResponse:@{
+                                 @"error": @{
+                                         @"message": message
+                                         }
+                                 }
+                       toEvent:eventData];
+}
+
+- (void)sendLocalisedError:(NSString*)errorKey toEvent:(NSDictionary*)eventData
+{
+    [self sendError:NSLocalizedStringFromTable(errorKey, @"Vector", nil) toEvent:eventData];
 }

@end