implement optional filtering in hyperjson

Implemented via callback, return falsey if you want to filter an element
and all of its children from the serialized result.

Conflicts:
	www/common/convert.js

www/common/convert.js

@@ -1,14 +1,16 @@
 define([
+    '/common/virtual-dom.js',
     '/common/hyperjson.js',
     '/common/hyperscript.js'
-], function (hyperjson, hyperscript) {
+], function (vdom, hyperjson, hyperscript) {
     // complain if you don't find the required APIs
-    if (!(hyperjson && hyperscript)) { throw new Error(); }
+    if (!(vdom && hyperjson && hyperscript)) { throw new Error(); }
 
     // Generate a matrix of conversions
     /*
         convert.dom.to.hjson, convert.hjson.to.dom,
         convert.dom.to.vdom, convert.vdom.to.dom,
+        convert.vdom.to.hjson, convert.hjson.to.vdom
 
         and of course, identify functions in case you try to
         convert a datatype to itself
@@ -20,13 +22,28 @@ define([
             methods = {
                 dom:{
                     dom: Self,
-                    hjson: hyperjson.fromDOM
+                    hjson: hyperjson.fromDOM,
+                    vdom: function (D) {
+                        return hyperjson.callOn(hyperjson.fromDOM(D), vdom.h);
+                    }
                 },
                 hjson:{
                     hjson: Self,
                     dom: function (H) {
                         // hyperjson.fromDOM,
                         return hyperjson.callOn(H, hyperscript);
+                    },
+                    vdom: function (H) {
+                        return hyperjson.callOn(H, vdom.h);
+                    }
+                },
+                vdom:{
+                    vdom: Self,
+                    dom: function (V) {
+                        return vdom.create(V);
+                    },
+                    hjson: function (V) {
+                        return hyperjson.fromDOM(vdom.create(V));
                     }
                 }
             },
@@ -38,6 +55,7 @@ define([
     }());
 
     convert.core = {
+        vdom: vdom,
         hyperjson: hyperjson,
         hyperscript: hyperscript
     };

www/common/hyperjson.js

@@ -47,13 +47,20 @@ define([], function () {
         return x;
     };
 
-    var DOM2HyperJSON = function(el){
+    var DOM2HyperJSON = function(el, predicate){
         if(!el.tagName && el.nodeType === Node.TEXT_NODE){
             return el.textContent;
         }
         if(!el.attributes){
           return;
         }
+
+        if (predicate) {
+            if (!predicate(el)) {
+                // shortcircuit
+                return;
+            }
+        }
         var attributes = {};
 
         var i = 0;
@@ -102,10 +109,12 @@ define([], function () {
 
         // js hint complains if we use 'var' here
         i = 0;
+
         for(; i < el.childNodes.length; i++){
-          children.push(DOM2HyperJSON(el.childNodes[i]));
+            children.push(DOM2HyperJSON(el.childNodes[i], predicate));
         }
-        result.push(children);
+
+        result.push(children.filter(isTruthy));
 
         return result;
     };