Easily show WKWebView alerts, prompts, and confirms

WKWebViewPanelManager.h

//
//  WKWebViewPanelManager.h
//
//  A few helpers to easily show WKWebView alerts, confirms, and prompts.
//
//  Created by Joshua Wright<@bendytree> on 11/4/15.
//
//  License: MIT
//
//  Inspired by: https://github.com/ShingoFukuyama/WKWebViewTips
//
//  Usage:
/*
    ...
 
    - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
        [WKWebViewPanelManager presentAlertOnController:self title:@"Alert" message:message handler:completionHandler];
    }

    - (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler {
        [WKWebViewPanelManager presentConfirmOnController:self title:@"Confirm" message:message handler:completionHandler];
    }

    - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * __nullable result))completionHandler {
        [WKWebViewPanelManager presentPromptOnController:self title:@"Prompt" message:prompt defaultText:defaultText handler:completionHandler];
    }
 
    ...
*/


#import <Foundation/Foundation.h>

@interface WKWebViewPanelManager : NSObject

+ (void) presentAlertOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message handler:(nonnull void (^)())completionHandler;
+ (void) presentConfirmOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message handler:(nonnull void (^)(BOOL result))completionHandler;
+ (void) presentPromptOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message defaultText:(nullable NSString*)defaultText handler:(nonnull void (^)(NSString * __nullable result))completionHandler;

@end

WKWebViewPanelManager.m

//
//  WKWebViewPanelManager.m
//
//  Created by Joshua Wright<@bendytree> on 11/4/15. MIT License.
//

#import "WKWebViewPanelManager.h"

@implementation WKWebViewPanelManager

+ (void) presentAlertOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message handler:(nonnull void (^)())completionHandler
{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        completionHandler();
    }]];
    [parentController presentViewController:alertController animated:YES completion:^{}];
}

+ (void) presentConfirmOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message handler:(nonnull void (^)(BOOL result))completionHandler
{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        completionHandler(YES);
    }]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        completionHandler(NO);
    }]];
    [parentController presentViewController:alertController animated:YES completion:^{}];
}


+ (void) presentPromptOnController:(nonnull UIViewController*)parentController title:(nullable NSString*)title message:(nullable NSString *)message defaultText:(nullable NSString*)defaultText handler:(nonnull void (^)(NSString * __nullable result))completionHandler
{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:message preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *textField) {
        textField.text = defaultText;
    }];
    [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        NSString *input = ((UITextField *)alertController.textFields.firstObject).text;
        completionHandler(input);
    }]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction *action) {
        completionHandler(nil);
    }]];
    [parentController presentViewController:alertController animated:YES completion:^{}];
}

@end