From 9cb75817e5f56695e6bf67e4112ae87bb1ae1930 Mon Sep 17 00:00:00 2001
From: "Xinlei(Ryan) Pan" <xinleiryan.pan@verizonwireless.com>
Date: Wed, 1 Apr 2020 19:15:49 -0400
Subject: [PATCH] check previous content

---
 MVMCoreUI/Atomic/Atoms/Views/WebView.swift | 41 +++++++++++++++++-----
 1 file changed, 33 insertions(+), 8 deletions(-)

diff --git a/MVMCoreUI/Atomic/Atoms/Views/WebView.swift b/MVMCoreUI/Atomic/Atoms/Views/WebView.swift
index 6e22d3f5..72c8c33a 100644
--- a/MVMCoreUI/Atomic/Atoms/Views/WebView.swift
+++ b/MVMCoreUI/Atomic/Atoms/Views/WebView.swift
@@ -27,6 +27,10 @@ import WebKit
         super.setupView()
         createWebView(messageHandler: mvmWebViewMessageHandler)
         pinSpinnerView()
+        
+        //init height for loading spinner
+        webViewHeight = webView?.heightAnchor.constraint(equalToConstant: 44)
+        webViewHeight?.isActive = true
     }
     
     func createWebView(messageHandler: String?) {
@@ -44,24 +48,37 @@ import WebKit
         addSubview(webView)
         NSLayoutConstraint.constraintPinSubview(toSuperview: webView)
     }
-    
 
     // MARK: - MVMCoreUIMoleculeViewProtocol
     override open func set(with model: MoleculeModelProtocol, _ delegateObject: MVMCoreUIDelegateObject?, _ additionalData: [AnyHashable : Any]?) {
+        
+        //store the previous webview properties
+        let previousHtmlString = webviewModel?.htmlString
+        let previousURL = webView?.url
+        
         super.set(with: model, delegateObject, additionalData)
         self.delegateObject = delegateObject
-        //init height for loading spinner
-        webViewHeight = webView?.heightAnchor.constraint(equalToConstant: 44)
-        webViewHeight?.isActive = true
         
         if let height = webviewModel?.height {
             webViewHeight?.constant = height
             dynamicHeight = false
         }
         if let url = webviewModel?.url {
-            webView?.load(URLRequest(url: url))
+            if let previousUrl = previousURL, url == previousUrl {
+                //dont load the new
+            } else {
+                webView?.load(URLRequest(url: url))
+                webViewHeight?.constant = 44
+                loadingSpinner.resumeSpinner()
+            }
         } else if let htmlString = webviewModel?.htmlString {
-            webView?.loadHTMLString(htmlString, baseURL: nil)
+            if let previousHTML = previousHtmlString, previousHTML == htmlString {
+                    //dont load the new html since they are the same html string as preivous
+            } else {
+                webViewHeight?.constant = 44
+                webView?.loadHTMLString(htmlString, baseURL: nil)
+                loadingSpinner.resumeSpinner()
+            }
         }
         
         if let borderColor = webviewModel?.borderColor?.cgColor {
@@ -105,8 +122,16 @@ extension WebView : WKUIDelegate {
         */
         if !webView.isLoading {
             webView.evaluateJavaScript("document.body.scrollHeight", completionHandler: { [weak self] (result, error) in
-                guard let self = self, let height = result as? CGFloat else { return }
-                self.webViewHeight?.constant = height
+                guard let self = self else {
+                    return
+                }
+                if let height = result as? CGFloat {
+                    self.webViewHeight?.constant = height
+                } else {
+                    //if failed to get height from javascript, using scrollview.contensize's height
+                    let scrollHeight = self.webView?.scrollView.contentSize.height
+                    self.webViewHeight?.constant = scrollHeight ?? 44
+                }
                 self.delegateObject?.moleculeDelegate?.moleculeLayoutUpdated(self)
             })
         }