Merge pull request #109 from common-workflow-language/force-outputs-bottom

Force outputs to the bottom of graphs using invis edge

Author: MarkRobbo

src/main/java/org/commonwl/view/graphviz/DotWriter.java

@@ -193,6 +193,16 @@ private void writeSteps(Workflow workflow) throws IOException {
                 }
             }
         }
+
+        // Workaround to force outputs to lowest ranking, see #104
+        writeLine("");
+        writeLine("  // Invisible links to force outputs to be at lowest rank");
+        for (Map.Entry<String, CWLStep> step : workflow.getSteps().entrySet()) {
+            writeLine("  \"" + step.getKey() + "\" -> \"" +
+                    workflow.getOutputs().keySet().iterator().next() +
+                    "\" [style=invis];");
+        }
+
     }
 
     /**

src/test/resources/graphviz/testWorkflow.dot

@@ -49,4 +49,9 @@ digraph workflow {
   "input2" -> "step1";
   "default1" [label="examplefile.jar", fillcolor="#D5AEFC"]
   "default1" -> "step1";
+
+  // Invisible links to force outputs to be at lowest rank
+  "default1" -> "output" [style=invis];
+  "step2" -> "output" [style=invis];
+  "step1" -> "output" [style=invis];
 }