From 7ccc9bf48e52fe525bd0c58439ed967d280dfaac Mon Sep 17 00:00:00 2001
From: Nico Rehwaldt <git_nikku@nixis.de>
Date: Sat, 22 Mar 2014 01:47:03 +0100
Subject: [PATCH] feat(BpmnTreeWalker): handle loose processes / only selected
 DI

---
 lib/BpmnTreeWalker.js | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/lib/BpmnTreeWalker.js b/lib/BpmnTreeWalker.js
index 759b5d53..3e666152 100644
--- a/lib/BpmnTreeWalker.js
+++ b/lib/BpmnTreeWalker.js
@@ -5,6 +5,9 @@ function BpmnTraverser(handler) {
   var elementDiMap = {};
   var elementGfxMap = {};
 
+  // list of containers already walked
+  var handledProcesses = [];
+
   ///// Helpers /////////////////////////////////
 
   function contextual(fn, ctx) {
@@ -19,8 +22,15 @@ function BpmnTraverser(handler) {
 
   function visit(element, di, ctx) {
 
+    var gfx = elementGfxMap[element.id];
+
+    // avoid multiple rendering of elements
+    if (gfx) {
+      return gfx;
+    }
+
     // call handler
-    var gfx = handler.element(element, di, ctx);
+    gfx = handler.element(element, di, ctx);
 
     // and log returned result
     elementGfxMap[element.id] = gfx;
@@ -78,8 +88,6 @@ function BpmnTraverser(handler) {
   ////// Semantic handling //////////////////////
 
   function handleDefinitions(definitions, diagram) {
-    buildDiMap(definitions);
-  
     // make sure we walk the correct bpmnElement
     
     var diagrams = definitions.diagrams;
@@ -99,6 +107,9 @@ function BpmnTraverser(handler) {
       return;
     }
 
+    // load DI from selected diagram only
+    handleDiagram(diagram);
+
     var rootElement = diagram.plane.bpmnElement;
 
     if (is(rootElement, 'bpmn:Process')) {
@@ -106,11 +117,25 @@ function BpmnTraverser(handler) {
     } else
     if (is(rootElement, 'bpmn:Collaboration')) {
       handleCollaboration(rootElement);
+
+      // force drawing of everything not yet drawn that is part of the target DI
+      handleUnhandledProcesses(definitions.rootElements);
     } else {
       throw new Error('unsupported root element for bpmndi:Diagram: ' + type.name);
     }
   }
 
+  function handleUnhandledProcesses(rootElements) {
+
+    // walk through all processes that have not yet been drawn and draw them
+    // (in case they contain lanes with DI information)
+    var processes = _.forEach(rootElements, function(e) {
+      return e.$type === 'bpmn:Process' && e.laneSets && handledProcesses.indexOf(e) !== -1;
+    });
+
+    processes.forEach(contextual(handleProcess));
+  }
+
   function handleDataAssociation(association, context) {
     visitIfDi(association, context);
   }
@@ -265,6 +290,9 @@ function BpmnTraverser(handler) {
     handleIoSpecification(process.ioSpecification, context);
 
     handleArtifacts(process.artifacts, context);
+
+    // log process handled
+    handledProcesses.push(process);
   }
 
   function handleMessageFlow(messageFlow, context) {