From dddc5cbd9e9aa0dc971d547980fad4bae970237b Mon Sep 17 00:00:00 2001
From: Michael Hackstein <michael@arangodb.com>
Date: Tue, 20 May 2014 16:22:44 +0200
Subject: [PATCH] Added an _exists function to the general-graph module, which
 checks if there is a graph with given name to avoid error throwing within
 apps

---
 .../modules/org/arangodb/general-graph.js     | 42 ++++++++++++-------
 js/common/tests/shell-general-graph.js        | 14 +------
 2 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/js/common/modules/org/arangodb/general-graph.js b/js/common/modules/org/arangodb/general-graph.js
index fa5c3dff60..1c0eaf88fc 100644
--- a/js/common/modules/org/arangodb/general-graph.js
+++ b/js/common/modules/org/arangodb/general-graph.js
@@ -119,6 +119,19 @@ var findOrCreateCollectionsByEdgeDefinitions = function (edgeDefinitions, noCrea
   ];
 };
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief internal function to get graphs collection
+////////////////////////////////////////////////////////////////////////////////
+
+var _getGraphCollection = function() {
+  var gCol = db._graphs;
+  if (gCol === null || gCol === undefined) {
+    throw "_graphs collection does not exist.";
+  }
+  return gCol;
+};
+
+
 
 // -----------------------------------------------------------------------------
 // --SECTION--                             module "org/arangodb/general-graph"
@@ -336,14 +349,11 @@ var edgeDefinitions = function () {
 
 var _create = function (graphName, edgeDefinitions) {
 
-  var gdb = db._graphs,
+  var gdb = _getGraphCollection(),
     g,
     graphAlreadyExists = true,
     collections;
 
-  if (gdb === null || gdb === undefined) {
-    throw "_graphs collection does not exist.";
-  }
   if (!graphName) {
     throw "a graph name is required to create a graph.";
   }
@@ -435,13 +445,9 @@ var Graph = function(graphName, edgeDefinitions, vertexCollections, edgeCollecti
 
 var _graph = function(graphName) {
 
-  var gdb = db._graphs,
+  var gdb = _getGraphCollection(),
     g, collections;
 
-  if (gdb === null || gdb === undefined) {
-    throw "_graphs collection does not exist.";
-  }
-
   try {
     g = gdb.document(graphName);
   } 
@@ -457,18 +463,22 @@ var _graph = function(graphName) {
   return new Graph(graphName, g.edgeDefinitions, collections[0], collections[1]);
 };
 
+////////////////////////////////////////////////////////////////////////////////
+/// @brief check if a graph exists.
+////////////////////////////////////////////////////////////////////////////////
+
+var _exists = function(graphId) {
+  var gCol = _getGraphCollection();
+  return gCol.exists(graphId);
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief drop a graph.
 ////////////////////////////////////////////////////////////////////////////////
 
 var _drop = function(graphId, dropCollections) {
 
-  var gdb = db._graphs;
-
-
-  if (gdb === null || gdb === undefined) {
-    throw "_graphs collection does not exist.";
-  }
+  var gdb = _getGraphCollection();
 
   if (!gdb.exists(graphId)) {
     throw "Graph " + graphId + " does not exist.";
@@ -477,7 +487,6 @@ var _drop = function(graphId, dropCollections) {
   if (dropCollections !== false) {
     var graph = gdb.document(graphId);
     var edgeDefinitions = graph.edgeDefinitions;
-    require("internal").print(edgeDefinitions);
     edgeDefinitions.forEach(
       function(edgeDefinition) {
         var from = edgeDefinition.from;
@@ -660,6 +669,7 @@ exports._graph = _graph;
 exports.edgeDefinitions = edgeDefinitions;
 exports._create = _create;
 exports._drop = _drop;
+exports._exists = _exists;
 
 // -----------------------------------------------------------------------------
 // --SECTION--                                                       END-OF-FILE
diff --git a/js/common/tests/shell-general-graph.js b/js/common/tests/shell-general-graph.js
index 23dc99faa4..3fb5e6ce46 100644
--- a/js/common/tests/shell-general-graph.js
+++ b/js/common/tests/shell-general-graph.js
@@ -424,19 +424,9 @@ function GeneralGraphAQLQueriesSuite() {
   var v3 = "UnitTestV3";
 
   var dropInclExcl = function() {
-    var col = db._collection("_graphs");
-    try {
-      col.remove(graphName);
-    } catch (e) {
-      return;
+    if (graph._exists(graphName)) {
+      graph._drop(graphName);
     }
-    var colList = [v1, v2, v3, included, excluded];
-    _.each(colList, function(c) {
-      var colToClear = db._collection(c);
-      if (col) {
-        colToClear.truncate();
-      }
-    });
   };
 
   var e1, e2, e3;