wkwebview-engine-localhost/src/ios/CDVWKWebViewEngine.m

/*
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you under the Apache License, Version 2.0 (the
 "License"); you may not use this file except in compliance
 with the License.  You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing,
 software distributed under the License is distributed on an
 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 */

#import "CDVWKWebViewEngine.h"
#import "CDVWKWebViewUIDelegate.h"
#import <Cordova/NSDictionary+CordovaPreferences.h>

#import <objc/message.h>

#define CDV_BRIDGE_NAME @"cordova"

@interface CDVWKWebViewEngine ()

@property (nonatomic, strong, readwrite) UIView* engineWebView;
@property (nonatomic, strong, readwrite) id <WKUIDelegate> uiDelegate;

@end

// see forwardingTargetForSelector: selector comment for the reason for this pragma
#pragma clang diagnostic ignored "-Wprotocol"

@implementation CDVWKWebViewEngine

@synthesize engineWebView = _engineWebView;

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super init];
    if (self) {
        if (!IsAtLeastiOSVersion(@"8.0")) {
            return nil;
        }
        self.uiDelegate = [[CDVWKWebViewUIDelegate alloc] initWithTitle:[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleDisplayName"]];

        WKUserContentController* userContentController = [[WKUserContentController alloc] init];
        [userContentController addScriptMessageHandler:self name:CDV_BRIDGE_NAME];

        WKWebViewConfiguration* configuration = [[WKWebViewConfiguration alloc] init];
        configuration.userContentController = userContentController;

        WKWebView* wkWebView = [[WKWebView alloc] initWithFrame:frame configuration:configuration];

        wkWebView.UIDelegate = self.uiDelegate;

        self.engineWebView = wkWebView;

        NSLog(@"Using WKWebView");
    }

    return self;
}

- (void)pluginInitialize
{
    // viewController would be available now. we attempt to set all possible delegates to it, by default

    WKWebView* wkWebView = (WKWebView*)_engineWebView;

    if ([self.viewController conformsToProtocol:@protocol(WKUIDelegate)]) {
        wkWebView.UIDelegate = (id <WKUIDelegate>)self.viewController;
    }

    if ([self.viewController conformsToProtocol:@protocol(WKNavigationDelegate)]) {
        wkWebView.navigationDelegate = (id <WKNavigationDelegate>)self.viewController;
    } else {
        wkWebView.navigationDelegate = (id <WKNavigationDelegate>)self;
    }

    if ([self.viewController conformsToProtocol:@protocol(WKScriptMessageHandler)]) {
        [wkWebView.configuration.userContentController addScriptMessageHandler:(id < WKScriptMessageHandler >)self.viewController name:@"cordova"];
    }

    [self updateSettings:self.commandDelegate.settings];
}

- (id)loadRequest:(NSURLRequest*)request
{
    SEL wk_sel = NSSelectorFromString(@"loadFileURL:allowingReadAccessToURL:");

    // the URL needs to be a file reference
    NSURL* url = request.URL;
    
    if ([_engineWebView respondsToSelector:wk_sel] && [url isFileReferenceURL]) {
        // allow the folder containing the file reference to be read as well
        NSURL* readAccessUrl = [request.URL URLByDeletingLastPathComponent];
        return ((id (*)(id, SEL, id, id))objc_msgSend)(_engineWebView, wk_sel, url, readAccessUrl);
    } else {
        return [(WKWebView*)_engineWebView loadRequest:request];
    }
}

- (id)loadHTMLString:(NSString*)string baseURL:(NSURL*)baseURL
{
    return [(WKWebView*)_engineWebView loadHTMLString:string baseURL:baseURL];
}

- (NSURL*) URL
{
    return [(WKWebView*)_engineWebView URL];
}

- (void)updateSettings:(NSDictionary*)settings
{
    WKWebView* wkWebView = (WKWebView*)_engineWebView;

    wkWebView.configuration.preferences.minimumFontSize = [settings cordovaFloatSettingForKey:@"MinimumFontSize" defaultValue:0.0];
    wkWebView.configuration.allowsInlineMediaPlayback = [settings cordovaBoolSettingForKey:@"AllowInlineMediaPlayback" defaultValue:NO];
    wkWebView.configuration.mediaPlaybackRequiresUserAction = [settings cordovaBoolSettingForKey:@"MediaPlaybackRequiresUserAction" defaultValue:YES];
    wkWebView.configuration.suppressesIncrementalRendering = [settings cordovaBoolSettingForKey:@"SuppressesIncrementalRendering" defaultValue:NO];
    wkWebView.configuration.mediaPlaybackAllowsAirPlay = [settings cordovaBoolSettingForKey:@"MediaPlaybackAllowsAirPlay" defaultValue:YES];

    /*
     wkWebView.configuration.preferences.javaScriptEnabled = [settings cordovaBoolSettingForKey:@"JavaScriptEnabled" default:YES];
     wkWebView.configuration.preferences.javaScriptCanOpenWindowsAutomatically = [settings cordovaBoolSettingForKey:@"JavaScriptCanOpenWindowsAutomatically" default:NO];
     */
    
    // By default, DisallowOverscroll is false (thus bounce is allowed)
    BOOL bounceAllowed = !([settings cordovaBoolSettingForKey:@"DisallowOverscroll" defaultValue:NO]);
    
    // prevent webView from bouncing
    if (!bounceAllowed) {
        if ([wkWebView respondsToSelector:@selector(scrollView)]) {
            ((UIScrollView*)[wkWebView scrollView]).bounces = NO;
        } else {
            for (id subview in wkWebView.subviews) {
                if ([[subview class] isSubclassOfClass:[UIScrollView class]]) {
                    ((UIScrollView*)subview).bounces = NO;
                }
            }
        }
    }
}

- (void)updateWithInfo:(NSDictionary*)info
{
    NSDictionary* scriptMessageHandlers = [info objectForKey:kCDVWebViewEngineScriptMessageHandlers];
    NSDictionary* settings = [info objectForKey:kCDVWebViewEngineWebViewPreferences];
    id navigationDelegate = [info objectForKey:kCDVWebViewEngineWKNavigationDelegate];
    id uiDelegate = [info objectForKey:kCDVWebViewEngineWKUIDelegate];

    WKWebView* wkWebView = (WKWebView*)_engineWebView;

    if (scriptMessageHandlers && [scriptMessageHandlers isKindOfClass:[NSDictionary class]]) {
        NSArray* allKeys = [scriptMessageHandlers allKeys];

        for (NSString* key in allKeys) {
            id object = [scriptMessageHandlers objectForKey:key];
            if ([object conformsToProtocol:@protocol(WKScriptMessageHandler)]) {
                [wkWebView.configuration.userContentController addScriptMessageHandler:object name:key];
            }
        }
    }

    if (navigationDelegate && [navigationDelegate conformsToProtocol:@protocol(WKNavigationDelegate)]) {
        wkWebView.navigationDelegate = navigationDelegate;
    }

    if (uiDelegate && [uiDelegate conformsToProtocol:@protocol(WKUIDelegate)]) {
        wkWebView.UIDelegate = uiDelegate;
    }

    if (settings && [settings isKindOfClass:[NSDictionary class]]) {
        [self updateSettings:settings];
    }
}

// This forwards the methods that are in the header that are not implemented here.
// Both WKWebView and UIWebView implement the below:
//     loadHTMLString:baseURL:
//     loadRequest:
- (id)forwardingTargetForSelector:(SEL)aSelector
{
    return _engineWebView;
}

#pragma mark WKScriptMessageHandler implementation

- (void)userContentController:(WKUserContentController*)userContentController didReceiveScriptMessage:(WKScriptMessage*)message
{
    if (![message.name isEqualToString:CDV_BRIDGE_NAME]) {
        return;
    }

    CDVViewController* vc = (CDVViewController*)self.viewController;

    NSArray* jsonEntry = message.body; // NSString:callbackId, NSString:service, NSString:action, NSArray:args
    CDVInvokedUrlCommand* command = [CDVInvokedUrlCommand commandFromJson:jsonEntry];
    CDV_EXEC_LOG(@"Exec(%@): Calling %@.%@", command.callbackId, command.className, command.methodName);

    if (![vc.commandQueue execute:command]) {
#ifdef DEBUG
        NSError* error = nil;
        NSString* commandJson = nil;
        NSData* jsonData = [NSJSONSerialization dataWithJSONObject:jsonEntry
                                                           options:0
                                                             error:&error];
        
        if (error == nil) {
            commandJson = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
        }

            static NSUInteger maxLogLength = 1024;
            NSString* commandString = ([commandJson length] > maxLogLength) ?
                [NSString stringWithFormat : @"%@[...]", [commandJson substringToIndex:maxLogLength]] :
                commandJson;

            NSLog(@"FAILED pluginJSON = %@", commandString);
#endif
    }
}

#pragma mark WKNavigationDelegate implementation

- (void)webView:(WKWebView*)webView didFinishNavigation:(WKNavigation*)navigation
{
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVPageDidLoadNotification object:webView]];
}

@end