Handle invalid URLs in share extension.

ios/chrome/share_extension/share_view_controller.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import <MobileCoreServices/MobileCoreServices.h>
 
 #import "ios/chrome/share_extension/share_view_controller.h"
 
 #import "base/ios/block_types.h"
 #import "base/mac/foundation_util.h"
@@ skipping 16 matching lines @@
 const CGFloat kShareExtensionMaxWidth = 390;
 // Clip the last separator out of the table view.
 const CGFloat kScreenShotWidth = 100;
 const CGFloat kScreenShotHeight = 100;
 const CGFloat kAnimationDuration = 0.3;
 const CGFloat kMediumAlpha = 0.5;
 
 }  // namespace
 
 @interface ShareViewController ()<ShareExtensionViewActionTarget> {
-  // This constraint the center of the widget to be vertically in the center
-  // of the the screen. It has to be modified for the dismissal animation.
-  NSLayoutConstraint* _centerYConstraint;
+  // This constrains the center of the widget to be vertically in the center

[gambard, 2017/01/02 10:55:08]

Why adding a "s" to constraint?

[Olivier, 2017/01/02 12:23:31]

Because constraint is a noun and constrain is a verb.

+  // of the the screen. It has to be modified for the appearance and dismissal
+  // animation.
+  NSLayoutConstraint* _widgetVerticalPlacementConstraint;
 
   NSURL* _shareURL;
   NSString* _shareTitle;
+  UIImage* _image;
   NSExtensionItem* _shareItem;
 }
 
 @property(nonatomic, weak) UIView* maskView;
 @property(nonatomic, weak) ShareExtensionView* shareView;
 @property(nonatomic, assign) app_group::ShareExtensionItemType itemType;
 
 // Creates a files in |app_group::ShareExtensionItemsFolder()| containing a
 // serialized NSDictionary.
 // If |cancel| is true, |actionType| is ignored.
 - (void)queueActionItemURL:(NSURL*)URL
                      title:(NSString*)title
                     action:(app_group::ShareExtensionItemType)actionType
                     cancel:(BOOL)cancel
                 completion:(ProceduralBlock)completion;
 
 // Loads all the shared elements from the extension context and update the UI.
 - (void)loadElementsFromContext;
 
 // Sets constaints to the widget so that margin are at least
 // kShareExtensionMargin points and widget width is closest up to
 // kShareExtensionMaxWidth points.
 - (void)constrainWidgetWidth;
 
+// Displays the normal share view.
+- (void)displayShareView;
+
+// Displays an alert to report an error to the user.
+- (void)displayErrorView;
+
 @end
 
 @implementation ShareViewController
 
 @synthesize maskView = _maskView;
 @synthesize shareView = _shareView;
 @synthesize itemType = _itemType;
 
 #pragma mark - UIViewController
 
@@ skipping 11 matching lines @@
   // This view is the main view of the share extension.
   ShareExtensionView* shareView =
       [[ShareExtensionView alloc] initWithActionTarget:self];
   [self setShareView:shareView];
   [self.view addSubview:self.shareView];
 
   [self constrainWidgetWidth];
 
   // Position the widget below the screen. It will be slided up with an
   // animation.
-  _centerYConstraint = [[shareView centerYAnchor]
-      constraintEqualToAnchor:[self.view centerYAnchor]];
-  [_centerYConstraint setConstant:(self.view.frame.size.height +
-                                   self.shareView.frame.size.height) /
-                                  2];
-  [_centerYConstraint setActive:YES];
+  _widgetVerticalPlacementConstraint =
+      [[shareView topAnchor] constraintEqualToAnchor:[self.view bottomAnchor]];
+  [_widgetVerticalPlacementConstraint setActive:YES];
   [[[shareView centerXAnchor] constraintEqualToAnchor:[self.view centerXAnchor]]
       setActive:YES];
 
   [self.maskView setTranslatesAutoresizingMaskIntoConstraints:NO];
   [self.shareView setTranslatesAutoresizingMaskIntoConstraints:NO];
 
   [self loadElementsFromContext];
 }
 
-- (void)viewWillAppear:(BOOL)animated {
-  [super viewWillAppear:animated];
-
-  // Center the widget.
-  [_centerYConstraint setConstant:0];
-  [self.maskView setAlpha:0];
-  [UIView animateWithDuration:kAnimationDuration
-                   animations:^{
-                     [self.maskView setAlpha:1];
-                     [self.view layoutIfNeeded];
-                   }];
-}
-
 #pragma mark - Private methods
 
+- (void)displayShareView {
+  [self.shareView setTitle:_shareTitle];
+  [self.shareView setURL:_shareURL];
+  if (_image) {
+    [self.shareView setScreenshot:_image];
+  }
+  dispatch_async(dispatch_get_main_queue(), ^{
+    // Center the widget.
+    [_widgetVerticalPlacementConstraint setActive:NO];

[gambard, 2017/01/02 10:55:08]

Nit: you could use dot syntax for readability, here and for the other
constraints

[Olivier, 2017/01/02 12:23:31]

setActive has a lot of consequences, so I prefer the call syntax.

+    _widgetVerticalPlacementConstraint = [[_shareView centerYAnchor]

[gambard, 2017/01/02 10:55:08]

Same for the centerYAnchor

[Olivier, 2017/01/02 12:23:31]

Done.

+        constraintEqualToAnchor:[self.view centerYAnchor]];
+    [_widgetVerticalPlacementConstraint setActive:YES];
+    [self.maskView setAlpha:0];
+    [UIView animateWithDuration:kAnimationDuration
+                     animations:^{
+                       [self.maskView setAlpha:1];
+                       [self.view layoutIfNeeded];
+                     }];
+  });
+}
+
+- (void)displayErrorView {
+  NSString* errorMessage =
+      NSLocalizedString(@"IDS_IOS_ERROR_MESSAGE_SHARE_EXTENSION",
+                        @"The error message to display to the user.");
+  NSString* okButton =
+      NSLocalizedString(@"IDS_IOS_OK_BUTTON_SHARE_EXTENSION",
+                        @"The label of the OK button in share extension.");
+  NSString* applicationName = [[[NSBundle mainBundle] infoDictionary]
+      valueForKey:@"CFBundleDisplayName"];
+  errorMessage =
+      [errorMessage stringByReplacingOccurrencesOfString:@"APPLICATION_NAME"
+                                              withString:applicationName];
+  UIAlertController* alert =
+      [UIAlertController alertControllerWithTitle:errorMessage
+                                          message:[_shareURL absoluteString]
+                                   preferredStyle:UIAlertControllerStyleAlert];
+  UIAlertAction* defaultAction =
+      [UIAlertAction actionWithTitle:okButton
+                               style:UIAlertActionStyleDefault
+                             handler:^(UIAlertAction* action) {
+                               [self dismissAndReturnItem:nil];
+                             }];
+  [alert addAction:defaultAction];
+  [self presentViewController:alert animated:YES completion:nil];
+}
+
 - (void)constrainWidgetWidth {
   // Setting the constraints.
   NSDictionary* views = @{ @"share" : self.shareView };
 
   NSDictionary* metrics = @{
     @"margin" : @(kShareExtensionMargin),
     @"maxWidth" : @(kShareExtensionMaxWidth),
   };
 
   NSArray* constraints = @[
@@ skipping 26 matching lines @@
       if ([itemProvider hasItemConformingToTypeIdentifier:typeURL]) {
         ItemBlock URLCompletion = ^(id idURL, NSError* error) {
           NSURL* URL = static_cast<NSURL*>(idURL);
           dispatch_async(dispatch_get_main_queue(), ^{
             _shareItem = [item copy];
             _shareURL = [URL copy];
             _shareTitle = [[[item attributedContentText] string] copy];
             if ([_shareTitle length] == 0) {
               _shareTitle = [URL host];
             }
-            [self.shareView setURL:URL];
-            [self.shareView setTitle:_shareTitle];
+            if ([[_shareURL scheme] isEqualToString:@"http"] ||
+                [[_shareURL scheme] isEqualToString:@"https"]) {
+              [self displayShareView];
+            } else {
+              [self displayErrorView];
+            }
           });
 
         };
         [itemProvider loadItemForTypeIdentifier:typeURL
                                         options:nil
                               completionHandler:URLCompletion];
         NSDictionary* imageOptions = @{
           NSItemProviderPreferredImageSizeKey : [NSValue
               valueWithCGSize:CGSizeMake(kScreenShotWidth, kScreenShotHeight)]
         };
-        ItemBlock ImageCompletion = ^(id item, NSError* error) {
-
-          UIImage* image = static_cast<UIImage*>(item);
-          if (image) {
+        ItemBlock imageCompletion = ^(id item, NSError* error) {
+          _image = static_cast<UIImage*>(item);
+          if (_image && self.shareView) {
             dispatch_async(dispatch_get_main_queue(), ^{
-              [self.shareView setScreenshot:image];
+              [self.shareView setScreenshot:_image];
             });
           }
-
         };
         [itemProvider loadPreviewImageWithOptions:imageOptions
-                                completionHandler:ImageCompletion];
+                                completionHandler:imageCompletion];
       }
     }
   }
 }
 
 - (void)dismissAndReturnItem:(NSExtensionItem*)item {
-  // Set the Y center constraints so the whole extension slides out of the
-  // screen. Constant is relative to the center of the screen.
+  // Set the Y placement constraints so the whole extension slides out of the
+  // screen.
   // The direction (up or down) is relative to the output (cancel or submit).
-  NSInteger direction = item ? -1 : 1;
-  [_centerYConstraint setConstant:direction *
-                                  (self.view.frame.size.height +
-                                   self.shareView.frame.size.height) /
-                                  2];
+  [_widgetVerticalPlacementConstraint setActive:NO];
+  if (item) {
+    _widgetVerticalPlacementConstraint = [[_shareView bottomAnchor]
+        constraintEqualToAnchor:[self.view topAnchor]];
+  } else {
+    _widgetVerticalPlacementConstraint = [[_shareView topAnchor]
+        constraintEqualToAnchor:[self.view bottomAnchor]];
+  }
+  [_widgetVerticalPlacementConstraint setActive:YES];
   [UIView animateWithDuration:kAnimationDuration
       animations:^{
         [self.maskView setAlpha:0];
         [self.view layoutIfNeeded];
       }
       completion:^(BOOL finished) {
         NSArray* returnItem = item ? @[ item ] : @[];
         [self.extensionContext completeRequestReturningItems:returnItem
                                            completionHandler:nil];
       }];
@@ skipping 76 matching lines @@
                   [self dismissAndReturnItem:_shareItem];
                 }];
 }
 
 - (void)shareExtensionView:(id)sender
                typeChanged:(app_group::ShareExtensionItemType)type {
   [self setItemType:type];
 }
 
 @end