Add "on event ID BLOCK" support

js/compiler/compiler.js

@@ -155,6 +155,9 @@ var modifiedSourceActions = {
                         eventPattern.bindings,
                         block.asES5);
   },
+  FacetSituation_onEvent: function (_on, _event, id, block) {
+    return '\n.addOnEventHandler((function(' + id.asES5 + ') ' + block.asES5 + '))';
+  },
   FacetSituation_during: function(_during, pattern, facetBlock) {
     return buildOnEvent(false,
                         'asserted',

js/compiler/syndicate.ohm

@@ -45,6 +45,7 @@ Syndicate <: ES5 {
   FacetSituation
     = assert FacetPattern AssertWhenClause? #(sc) -- assert
     | on FacetEventPattern FunctionBodyBlock      -- event
+    | on event identifier FunctionBodyBlock       -- onEvent
     | during FacetPattern FacetBlock              -- during
 
   AssertWhenClause = when "(" Expression<withIn> ")"
@@ -77,6 +78,7 @@ Syndicate <: ES5 {
   assertion = "assertion" ~identifierPart
   dataspace = "dataspace" ~identifierPart
   during = "during" ~identifierPart
+  event = "event" ~identifierPart
   ground = "ground" ~identifierPart
   message = "message" ~identifierPart
   metalevel = "metalevel" ~identifierPart

js/src/actor.js

@@ -93,6 +93,10 @@ Facet.prototype.addAssertion = function(assertionFn) {
   return this.addEndpoint(new Endpoint(assertionFn, function(e) {}));
 };
 
+Facet.prototype.addOnEventHandler = function(handler) {
+  return this.addEndpoint(new Endpoint(function () { return Patch.emptyPatch; }, handler));
+};
+
 Facet.prototype.onEvent = function(isTerminal, eventType, subscriptionFn, projectionFn, handlerFn) {
   var facet = this;
   switch (eventType) {