                 viewModel.status = .idle
             }
         case .failure(let error):
+            isErrorOccured = true
             showPromptInformation(of: .failure("\(error)"))
             viewModel.status = .idle
             if webView.status == .loading {

    fileprivate func  handleDataLoadResult(_ result: PostResult) {
        switch result {
        case .success(let html):
            if viewModel.hasData {
                let options = animationOptions(of: viewModel.status)
                UIView.transition(with: webView, duration: C.UI.animationDuration * 4.0, options: options, animations: {

        pageNumberButton.setTitle(title, for: .normal)
        pageNumberButton.sizeToFit()
        refreshButton.imageView?.tintColor = C.Color.navigationBarTintColor
        
        if isErrorOccured {
            navigationItem.rightBarButtonItems = [UIBarButtonItem(customView: isLoading ? activityIndicator : refreshButton)]
        } else {
            navigationItem.rightBarButtonItems = [UIBarButtonItem(customView: moreButton),
                                                  UIBarButtonItem(customView: isLoading ? activityIndicator : refreshButton),
                                                  UIBarButtonItem(customView: replyButton),
                                                  UIBarButtonItem(customView: pageNumberButton)]
        }
    }
    
    fileprivate func animationOptions(of status: PostViewStatus) -> UIViewAnimationOptions {
