UIWebView+TrueHeight.h

//
//  UIWebView+TrueHeight.h
//  RAWebViewTrueHeight
//
//  Created by Stephen Keep on 08/03/2013.
//  Copyright (c) 2013 Stephen Keep. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface UIWebView (TrueHeight) <UIWebViewDelegate> 

@property (nonatomic, strong) UIViewController* parentViewController;

@end

UIWebView+TrueHeight.m

//
//  UIWebView+TrueHeight.m
//  RAWebViewTrueHeight
//
//  Created by Stephen Keep on 08/03/2013.
//  Copyright (c) 2013 Stephen Keep. All rights reserved.
//

#import "UIWebView+TrueHeight.h"
#import <objc/runtime.h>

static char const * const parentViewControllerKey = "parentViewController";

@implementation UIWebView (TrueHeight)

@dynamic parentViewController;

- (UIViewController *)parentViewController {
    return objc_getAssociatedObject(self, parentViewControllerKey);
}

- (void)setParentViewController:(id)parentViewController {
    objc_setAssociatedObject(self, parentViewControllerKey, parentViewController, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

-(BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    
    NSURL *url = request.URL;
    if ([url.scheme isEqual:@"height"]) {

        [self webViewDidFinishLoadWithTrueHeight:[url.host floatValue]];
        
        return NO;
    }
    
    return YES;
}

-(void)webViewDidFinishLoad:(UIWebView *)webView {
    
    float height = [[self stringByEvaluatingJavaScriptFromString:@"document.body.scrollHeight;"] floatValue];
    [self webViewDidFinishLoadWithTrueHeight:height];

    NSString *jquery = [[NSBundle mainBundle] pathForResource:@"jquery.min" ofType:@"js"];
    
    [webView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"var script = document.createElement('script');"
     "script.type = 'text/javascript';"
     "script.src = '%@';"
     "document.getElementsByTagName('head')[0].appendChild(script);",jquery]];
    
    [webView stringByEvaluatingJavaScriptFromString:@"var script = document.createElement('script');"
     "script.type = 'text/javascript';"
     "script.text = \"$(document).ready(function() {"
     "window.location = 'height://'+$(document).height();"
     "})\";"
     "$(\"body\").append(script);"];
        
}


-(void)webViewDidFinishLoadWithTrueHeight:(float)height {
    
    if (self.parentViewController && [self.parentViewController respondsToSelector:@selector(webViewDidFinishLoadWithTrueHeight:)]) {
        [self.parentViewController performSelector:@selector(webViewDidFinishLoadWithTrueHeight:) withObject:[NSNumber numberWithFloat:height]];
    }
    
}


@end

ViewController.m

//
//  ViewController.m
//  RAWebViewTrueHeight
//
//  Created by Stephen Keep on 08/03/2013.
//  Copyright (c) 2013 Stephen Keep. All rights reserved.
//

#import "ViewController.h"
#import "UIWebView+TrueHeight.h"

@interface ViewController () 

@property (nonatomic, strong) IBOutlet UIWebView *webView;

@end

@implementation ViewController

-(void)viewDidLoad {
    [super viewDidLoad];

    [self.webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.redant.com"]]];
    self.webView.parentViewController = self;
    
    self.webView.delegate = self.webView;
    
}

-(void)webViewDidFinishLoadWithTrueHeight:(NSNumber *)height {
    NSLog(@"vc: %.2f",[height floatValue]);
}

@end