From db8bb9b749f8dec0f6859b324a1fe53d05b9a8e8 Mon Sep 17 00:00:00 2001
From: Jay Qi <jay.qi@uptake.com>
Date: Wed, 12 Sep 2018 18:47:08 -0500
Subject: [PATCH] Changed several methods to return invisible(self) for
 chaining

---
 R/module_custom_function.R  |  8 ++++----
 R/module_package_function.R |  6 +++---
 R/workflow_dag.R            | 14 +++++++-------
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/R/module_custom_function.R b/R/module_custom_function.R
index 56574c0..3f356df 100644
--- a/R/module_custom_function.R
+++ b/R/module_custom_function.R
@@ -117,7 +117,7 @@ CustomFunctionModule <- R6::R6Class("CustomFunctionModule"
             private$name <- name
             private$fun <- fun
          
-            self$errorCheck()
+            return(self$errorCheck())
         }
      
         , clearOutputCache = function() {
@@ -128,7 +128,7 @@ CustomFunctionModule <- R6::R6Class("CustomFunctionModule"
          
             private$futurePromise <- NULL
          
-            return(invisible(NULL))
+            return(invisible(self))
         }
      
         , errorCheck = function(executionCheck = FALSE
@@ -146,7 +146,7 @@ CustomFunctionModule <- R6::R6Class("CustomFunctionModule"
                 UpDraftSettings$errorLogger("fun must be a reference to a function")
             }
          
-            return(invisible(NULL))
+            return(invisible(self))
         }
      
         , getFuncObj = function() {
@@ -193,7 +193,7 @@ CustomFunctionModule <- R6::R6Class("CustomFunctionModule"
                                                         , args =  args
                                                         , funcName = self$getName())
          
-            return(NULL)
+            return(invisible(NULL))
         }
     )      
  
diff --git a/R/module_package_function.R b/R/module_package_function.R
index 5fe0bb0..7a2446e 100644
--- a/R/module_package_function.R
+++ b/R/module_package_function.R
@@ -137,7 +137,7 @@ PackageFunctionModule <- R6::R6Class("PackageFunctionModule"
                 private$assignedProcesses <- assignedProcesses   
             }
             
-            self$errorCheck()
+            return(self$errorCheck())
         }
         
         , clearOutputCache = function() {
@@ -148,7 +148,7 @@ PackageFunctionModule <- R6::R6Class("PackageFunctionModule"
 
             private$futurePromise <- NULL
 
-            return(invisible(NULL))
+            return(invisible(self))
         }
         
         , errorCheck = function(executionCheck = FALSE
@@ -170,7 +170,7 @@ PackageFunctionModule <- R6::R6Class("PackageFunctionModule"
                 UpDraftSettings$errorLogger("assignedProcesses must be a single whole number numeric")    
             }
             
-            return(NULL)
+            return(invisible(self))
         }
         
         , getName = function() {
diff --git a/R/workflow_dag.R b/R/workflow_dag.R
index 9a4cdfa..44be0dc 100644
--- a/R/workflow_dag.R
+++ b/R/workflow_dag.R
@@ -196,7 +196,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
             private$connections <- list()
             private$graph <- igraph::graph.empty()
 
-            self$errorCheck()
+            return(self$errorCheck())
         }
 
         , addConnections = function(connections) {
@@ -225,7 +225,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
                 })
             }
 
-            return(invisible(NULL))
+            return(invisible(self))
         }
 
         , addModules = function(modules) {
@@ -251,7 +251,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
                 })
             }
 
-            return(invisible(NULL))
+            return(invisible(self))
         }
 
         , errorCheck = function(executionCheck = FALSE
@@ -301,7 +301,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
                 }
             }
 
-            return(NULL)
+            return(invisible(self))
         }
 
         , getWorkflowInputs = function() {
@@ -440,7 +440,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
 
             private$connections[connection] <- NULL
 
-            return(NULL)
+            return(invisible(self))
         }
 
         , removeModule = function(module)  {
@@ -461,7 +461,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
                                        , names(igraph::E(private$graph)))
             private$connections[connectionsLost] <- NULL
 
-            return(NULL)
+            return(invisible(self))
         }
 
         , save = function(filename) {
@@ -482,7 +482,7 @@ DAGWorkflow <- R6::R6Class("DAGWorkflow"
 
             write(jsonlite::toJSON(workflowData), filename)
 
-            return(NULL)
+            return(invisible(self))
         }
 
         , visualize = function() {