From 53e9971edd9449024c2f8056db80313bd688affd Mon Sep 17 00:00:00 2001
From: Don Rouse <Don@HotelDon.com>
Date: Thu, 25 Aug 2016 03:46:47 -0700
Subject: [PATCH] Add JSON pointer support to $data reference.

---
 lib/compile/util.js          | 33 +++++++++++++++++++++++----------
 lib/refs/json-schema-v5.json |  5 ++++-
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/lib/compile/util.js b/lib/compile/util.js
index f79a906..124be27 100644
--- a/lib/compile/util.js
+++ b/lib/compile/util.js
@@ -214,20 +214,33 @@ function getPath(currentPath, prop, jsonPointers) {
 }
 
 
+var JSON_POINTER = /^#|\/(?:[^~]|~0|~1)*?$/;
 var RELATIVE_JSON_POINTER = /^([0-9]+)(#|\/(?:[^~]|~0|~1)*)?$/;
 function getData($data, lvl, paths) {
-  var matches = $data.match(RELATIVE_JSON_POINTER);
-  if (!matches) throw new Error('Invalid relative JSON-pointer: ' + $data);
-  var up = +matches[1];
-  var jsonPointer = matches[2];
-  if (jsonPointer == '#') {
-    if (up >= lvl) throw new Error('Cannot access property/index ' + up + ' levels up, current level is ' + lvl);
-    return paths[lvl - up];
+  var up;
+  var jsonPointer;
+  var data;
+  var matches;
+  if ($data.charAt(0) == '/') {
+    matches = $data.match(JSON_POINTER);
+    if (!matches) throw new Error('Invalid JSON-pointer: ' + $data);
+    jsonPointer = matches[0];
+    data = 'data';
   }
+  else {
+    matches = $data.match(RELATIVE_JSON_POINTER);
+    if (!matches) throw new Error('Invalid JSON-pointer: ' + $data);
+    up = +matches[1];
+    jsonPointer = matches[2];
+    if (jsonPointer == '#') {
+      if (up >= lvl) throw new Error('Cannot access property/index ' + up + ' levels up, current level is ' + lvl);
+      return paths[lvl - up];
+    }
 
-  if (up > lvl) throw new Error('Cannot access data ' + up + ' levels up, current level is ' + lvl);
-  var data = 'data' + ((lvl - up) || '');
-  if (!jsonPointer) return data;
+    if (up > lvl) throw new Error('Cannot access data ' + up + ' levels up, current level is ' + lvl);
+    data = 'data' + ((lvl - up) || '');
+    if (!jsonPointer) return data;
+  }
 
   var expr = data;
   var segments = jsonPointer.split('/');
diff --git a/lib/refs/json-schema-v5.json b/lib/refs/json-schema-v5.json
index 8905d77..5964042 100644
--- a/lib/refs/json-schema-v5.json
+++ b/lib/refs/json-schema-v5.json
@@ -30,7 +30,10 @@
             "properties": {
                 "$data": {
                     "type": "string",
-                    "format": "relative-json-pointer"
+                    "anyOf": [
+                        { "format": "relative-json-pointer" }, 
+                        { "format": "json-pointer" }
+                    ]
                 }
             },
             "additionalProperties": false