adding callback removed assert fail

Author: MYK

README.md

@@ -25,5 +25,5 @@ The embedded web server is the header-only cpp-httplib by Yuji Hirose from here:
 # TODO
 
 * [DONE] web interface  -> cpp comms
-* [DONE except annoying assert] cpp -> web interface comms
+* [DONE] cpp -> web interface comms
 * test on mac and windows

src/PluginEditor.cpp

@@ -52,8 +52,16 @@ void PluginEditor::updateUIFromProcessor(const juce::String& msg)
     obj->setProperty("msg", msg);
     juce::var data(obj);
     juce::String json = juce::JSON::toString(data);
-    
-    webView.evaluateJavascript("handleCppMessage(" + json + ");", nullptr);
+    // eval some javascript in the webui which causes it to call
+    // a function called handleCppMessage with the data
+    webView.evaluateJavascript("handleCppMessage(" + json + ");", 
+        [](juce::WebBrowserComponent::EvaluationResult result) {
+            std::cout << "PluginEditor::updateUIFromProcessor js eval completed with res : " << result.getResult() << std::endl;
+            // code to run once the javascript has been evaluated ... 
+            // e.g. maybe re-enable the animation loop if you are waiting
+            // for a UI update 
+        }
+    );
 
     // std::string msg_as_json = "{\"msg\":\""+ msg + "\"}";
     // juce::JSON::toString({"msg":msg});

src/ui/index.html

@@ -13,7 +13,7 @@ <h1>I am served</h1>
 // the cpp back end will send us messages
 function handleCppMessage(data){
   // data = JSON.parse(json_string);
-  console.log(data["msg"])
+  console.log("javascript function  handleCppMessage received some data: " + data["msg"])
   msg_div = document.getElementById("messages");
   msg_div.innerText = data.msg;