better graphviz init

src/main/webapp/index.html

@@ -2903,19 +2903,20 @@ application {
   <script src="webjars/reveal.js/lib/js/head.min.js"></script>
   <script src="webjars/reveal.js/js/reveal.js"></script>
   <script src="webjars/hpcc-js__wasm/1.16.5/dist/index.js"></script>
-  <script>
-    var graphviz = window["@hpcc-js/wasm"].graphviz;
-  </script>
+  <script src="lib/plugin/graphviz.js"></script>
   <script src="teavm/classes.js"></script>
  
   <script>
+  (async () => {
+    // rendering graphviz diagrams to SVG
+    await allGraphvizToSVG().then(() => { console.log("all graphviz rendered.") });
+
     // Required, even if empty.
     Reveal.initialize({
       transition: 'convex',
 
       // Optional reveal.js plugins
       dependencies: [
-        { src: 'lib/plugin/graphviz.js', async: true },
         { src: 'webjars/reveal.js/plugin/highlight/highlight.js', async: true, callback: function() { hljs.initHighlightingOnLoad(); } }
       ]
     });
@@ -2954,7 +2955,7 @@ application {
     });
 
     // inline source files from data-src
-    (function (){
+    Reveal.addEventListener( 'ready', function (){
         var codeDataSrc = document.querySelectorAll('code[data-src]');
         Array.prototype.forEach.call(codeDataSrc, function(element) {
         	var srcUrl = element.getAttribute('data-src');
@@ -2968,7 +2969,7 @@ application {
         	title.innerText = srcUrl;
         	element.parentElement.insertBefore(title, element);
         });
-    })();
+    });
     function loadFile(src, cb) {
     	var xhr = new XMLHttpRequest();
     	xhr.responseType = 'text';
@@ -2987,6 +2988,7 @@ application {
     // force SVG repaint on slidechanged (avoid random svg text misplaced/missized)
     Reveal.addEventListener('slidechanged', (event) => Array.prototype.forEach.call(event.currentSlide.querySelectorAll('svg'), (svg) => svg.innerHTML += ""));
 
+  })();
     </script>
 </body>
 </html>

src/main/webapp/lib/plugin/graphviz.js

 // START CUSTOM HPCC-JS/WASM GRAPHVIZ INTEGRATION
-(function() {
+var graphviz = window["@hpcc-js/wasm"].graphviz;
+
+function allGraphvizToSVG() {
                 var graphs = document.querySelectorAll( 'pre.viz, script[type="text/vnd.graphviz"]' );
-                Array.prototype.forEach.call(graphs, function(element) {
+                return Promise.allSettled(Array.prototype.map.call(graphs, graphvizToSVG));
+            }
+
+function graphvizToSVG(element) {
                         if (element.parentNode === null) {
                           console.error('parentNode is null for', element);
-                          return;
+                          throw new Error('parentNode is null');
                         }
 
                         var graph = element.innerHTML;
@@ -19,15 +24,10 @@
                         //        element.innerHTML = element.innerHTML.replace(/</g,"&lt;").replace(/>/g,"&gt;");
                         //}
 
-                        //element.innerHTML = ansi_up.ansi_to_html(element.textContent, { 'use_classes': true });
-                        // var options = { format: 'svg' };
-                        // if( element.hasAttribute( 'data-engine' )) {
-                        //    options['engine'] = element.getAttribute('data-engine');
-                        // }
-                        graphviz.dot(graph)
+                        return graphviz.layout(graph, 'svg', element.hasAttribute('data-engine')?element.getAttribute('data-engine'):'dot')
                               .then(function(svgString) {
                                   var parser = new DOMParser();
-                                  var svg = parser.parseFromString(svgString, "image/svg+xml").documentElement
+                                  var svg = parser.parseFromString(svgString, "image/svg+xml").documentElement;
                                   // copy attributes
                                   for (var i=0; i<element.attributes.length; i++)
                                     if (!svg.hasAttribute(element.attributes[i].name))
@@ -45,9 +45,7 @@
                                   err_eltp.appendChild(err_eltc);
                                   err_elt.appendChild(err_eltp);
                                   element.parentNode.replaceChild(err_elt, element);
-                                  console.log(err)
                               });
-                });
-})();
+                }
 // END CUSTOM HPCC-JS/WASM GRAPHVIZ INTEGRATION
 // REQUIRE @hpcc-js/wasm