From dbf0486acb36d9f8430ab0a0e829e86f01ef1a53 Mon Sep 17 00:00:00 2001
From: Nick O'Leary <nick.oleary@gmail.com>
Date: Fri, 5 May 2017 11:23:24 +0100
Subject: [PATCH] Add JSONata expr tester and improved feedback

---
 Gruntfile.js                           |   1 +
 editor/js/ui/common/panels.js          |  83 +++++++++++++++
 editor/js/ui/editor.js                 | 140 +++++++++++++++++++++++--
 editor/js/ui/tab-info.js               |   3 +-
 editor/sass/editor.scss                |  51 ++++++++-
 editor/sass/panels.scss                |  23 ++++
 editor/sass/style.scss                 |   1 +
 editor/templates/index.mst             |  43 +++++---
 editor/vendor/jsonata/formatter.js     |   5 +-
 nodes/core/locales/en-US/messages.json |   5 +-
 nodes/core/logic/10-switch.js          |   6 +-
 nodes/core/logic/15-change.js          |  11 +-
 red/api/locales/en-US/editor.json      |  10 +-
 red/api/locales/en-US/jsonata.json     |   9 +-
 red/runtime/util.js                    |  23 ++--
 15 files changed, 362 insertions(+), 52 deletions(-)
 create mode 100644 editor/js/ui/common/panels.js
 create mode 100644 editor/sass/panels.scss

diff --git a/Gruntfile.js b/Gruntfile.js
index b9c962c87..e921be3c5 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -124,6 +124,7 @@ module.exports = function(grunt) {
                     "editor/js/ui/utils.js",
                     "editor/js/ui/common/editableList.js",
                     "editor/js/ui/common/menu.js",
+                    "editor/js/ui/common/panels.js",
                     "editor/js/ui/common/popover.js",
                     "editor/js/ui/common/searchBox.js",
                     "editor/js/ui/common/tabs.js",
diff --git a/editor/js/ui/common/panels.js b/editor/js/ui/common/panels.js
new file mode 100644
index 000000000..fbe595662
--- /dev/null
+++ b/editor/js/ui/common/panels.js
@@ -0,0 +1,83 @@
+/**
+ * Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+
+RED.panels = (function() {
+
+    function createPanel(options) {
+        var container = options.container || $("#"+options.id);
+        var children = container.children();
+        if (children.length !== 2) {
+            throw new Error("Container must have exactly two children");
+        }
+
+        container.addClass("red-ui-panels");
+        var separator = $('<div class="red-ui-panels-separator"></div>').insertAfter(children[0]);
+        var startPosition;
+        var panelHeights = [];
+        var modifiedHeights = false;
+        var panelRatio;
+
+        separator.draggable({
+                axis: "y",
+                containment: container,
+                scroll: false,
+                start:function(event,ui) {
+                    var height = container.height();
+                    startPosition = ui.position.top;
+                    panelHeights = [$(children[0]).height(),$(children[1]).height()];
+                    console.log("START",height,panelHeights,panelHeights[0]+panelHeights[1],height-(panelHeights[0]+panelHeights[1]));
+                },
+                drag: function(event,ui) {
+                    var height = container.height();
+                    var delta = ui.position.top-startPosition;
+                    var newHeights = [panelHeights[0]+delta,panelHeights[1]-delta];
+                    $(children[0]).height(newHeights[0]);
+                    $(children[1]).height(newHeights[1]);
+                    if (options.resize) {
+                        options.resize(newHeights[0],newHeights[1]);
+                    }
+                    ui.position.top -= delta;
+                    panelRatio = newHeights[0]/height;
+                },
+                stop:function(event,ui) {
+                    modifiedHeights = true;
+                }
+        });
+
+        return {
+            resize: function(height) {
+                var panelHeights = [$(children[0]).height(),$(children[1]).height()];
+                container.height(height);
+                if (modifiedHeights) {
+                    var topPanelHeight = panelRatio*height;
+                    var bottomPanelHeight = height - topPanelHeight - 48;
+                    panelHeights = [topPanelHeight,bottomPanelHeight];
+                    $(children[0]).height(panelHeights[0]);
+                    $(children[1]).height(panelHeights[1]);
+                    console.log("SET",height,panelHeights,panelHeights[0]+panelHeights[1],height-(panelHeights[0]+panelHeights[1]));
+                }
+                if (options.resize) {
+                    options.resize(panelHeights[0],panelHeights[1]);
+                }
+            }
+        }
+    }
+
+    return {
+        create: createPanel
+    }
+})();
diff --git a/editor/js/ui/editor.js b/editor/js/ui/editor.js
index d742ab80f..9164be349 100644
--- a/editor/js/ui/editor.js
+++ b/editor/js/ui/editor.js
@@ -1598,6 +1598,9 @@ RED.editor = (function() {
         editStack.push({type:type});
         RED.view.state(RED.state.EDITING);
         var expressionEditor;
+        var testDataEditor;
+        var testResultEditor
+        var panels;
 
         var trayOptions = {
             title: getEditStackTitle(),
@@ -1621,20 +1624,18 @@ RED.editor = (function() {
                 }
             ],
             resize: function(dimensions) {
-                editTrayWidthCache[type] = dimensions.width;
-
-                var rows = $("#dialog-form>div:not(.node-text-editor-row)");
-                var editorRow = $("#dialog-form>div.node-text-editor-row");
-                var height = $("#dialog-form").height();
-                for (var i=0;i<rows.size();i++) {
-                    height -= $(rows[i]).outerHeight(true);
+                if (dimensions) {
+                    editTrayWidthCache[type] = dimensions.width;
                 }
-                height -= (parseInt($("#dialog-form").css("marginTop"))+parseInt($("#dialog-form").css("marginBottom")));
-                $(".node-text-editor").css("height",height+"px");
-                expressionEditor.resize();
+                var height = $("#dialog-form").height();
+                if (panels) {
+                    panels.resize(height);
+                }
+
             },
             open: function(tray) {
                 var trayBody = tray.find('.editor-tray-body');
+                trayBody.addClass("node-input-expression-editor")
                 var dialogForm = buildEditForm(tray.find('.editor-tray-body'),'dialog-form','_expression','editor');
                 var funcSelect = $("#node-input-expression-func");
                 Object.keys(jsonata.functions).forEach(function(f) {
@@ -1749,6 +1750,118 @@ RED.editor = (function() {
                     }
                     expressionEditor.getSession().setValue(v||"",-1);
                 });
+
+                var tabs = RED.tabs.create({
+                    element: $("#node-input-expression-tabs"),
+                    onchange:function(tab) {
+                        $(".node-input-expression-tab-content").hide();
+                        tab.content.show();
+                        trayOptions.resize();
+                    }
+                })
+
+                tabs.addTab({
+                    id: 'expression-help',
+                    label: 'Function reference',
+                    content: $("#node-input-expression-tab-help")
+                });
+                tabs.addTab({
+                    id: 'expression-tests',
+                    label: 'Test',
+                    content: $("#node-input-expression-tab-test")
+                });
+                testDataEditor = RED.editor.createEditor({
+                    id: 'node-input-expression-test-data',
+                    value: '{\n    "payload": "hello world"\n}',
+                    mode:"ace/mode/json",
+                    lineNumbers: false
+                });
+                var changeTimer;
+                $(".node-input-expression-legacy").click(function(e) {
+                    e.preventDefault();
+                    RED.sidebar.info.set(RED._("expressionEditor.compatModeDesc"));
+                    RED.sidebar.info.show();
+                })
+                var testExpression = function() {
+                    var value = testDataEditor.getValue();
+                    var parsedData;
+                    var currentExpression = expressionEditor.getValue();
+                    var expr;
+                    var usesContext = false;
+                    var legacyMode = false;
+                    try {
+                        expr = jsonata(currentExpression);
+                        expr.assign('flow',function(val) {
+                            usesContext = true;
+                            return null;
+                        });
+                        expr.assign('global',function(val) {
+                            usesContext = true;
+                            return null;
+                        });
+                        legacyMode = /(^|[^a-zA-Z0-9_'"])msg([^a-zA-Z0-9_'"]|$)/.test(currentExpression);
+                    } catch(err) {
+                        testResultEditor.setValue("Invalid jsonata expression:\n  "+err.message);
+                        return;
+                    }
+                    $(".node-input-expression-legacy").toggle(legacyMode);
+                    try {
+                        parsedData = JSON.parse(value);
+                    } catch(err) {
+                        testResultEditor.setValue("Invalid example message:\n  "+err.toString())
+                        return;
+                    }
+
+                    try {
+                        var result = expr.evaluate(legacyMode?{msg:parsedData}:parsedData);
+                        if (usesContext) {
+                            testResultEditor.setValue("Cannot test a function that uses context values");
+                            return;
+                        }
+                        var formattedResult = JSON.stringify(result,null,4);
+                        testResultEditor.setValue(formattedResult || "No match");
+                    } catch(err) {
+                        testResultEditor.setValue("Error evaluating expression:\n  "+err.message);
+                    }
+                }
+
+                testDataEditor.getSession().on('change', function() {
+                    clearTimeout(changeTimer);
+                    changeTimer = setTimeout(testExpression,200);
+                });
+                expressionEditor.getSession().on('change', function() {
+                    clearTimeout(changeTimer);
+                    changeTimer = setTimeout(testExpression,200);
+                });
+
+                testResultEditor = RED.editor.createEditor({
+                    id: 'node-input-expression-test-result',
+                    value: "",
+                    mode:"ace/mode/json",
+                    lineNumbers: false,
+                    readOnly: true
+                });
+                panels = RED.panels.create({
+                    id:"node-input-expression-panels",
+                    resize: function(p1Height,p2Height) {
+                        var p1 = $("#node-input-expression-panel-expr");
+                        p1Height -= $(p1.children()[0]).outerHeight(true);
+                        var editorRow = $(p1.children()[1]);
+                        p1Height -= (parseInt(editorRow.css("marginTop"))+parseInt(editorRow.css("marginBottom")));
+                        $("#node-input-expression").css("height",(p1Height-5)+"px");
+                        expressionEditor.resize();
+
+                        var p2 = $("#node-input-expression-panel-info > .form-row > div:first-child");
+                        p2Height -= p2.outerHeight(true) + 20;
+                        $(".node-input-expression-tab-content").height(p2Height);
+                        $("#node-input-expression-test-data").css("height",(p2Height-5)+"px");
+                        testDataEditor.resize();
+                        $("#node-input-expression-test-result").css("height",(p2Height-5)+"px");
+                        testResultEditor.resize();
+                    }
+                });
+
+                testExpression();
             },
             close: function() {
                 editStack.pop();
@@ -1855,6 +1968,7 @@ RED.editor = (function() {
         validateNode: validateNode,
         updateNodeProperties: updateNodeProperties, // TODO: only exposed for edit-undo
 
+
         createEditor: function(options) {
             var editor = ace.edit(options.id);
             editor.setTheme("ace/theme/tomorrow");
@@ -1875,6 +1989,12 @@ RED.editor = (function() {
                     enableSnippets:true
                 });
             }
+            if (options.readOnly) {
+                editor.setOption('readOnly',options.readOnly);
+            }
+            if (options.hasOwnProperty('lineNumbers')) {
+                editor.renderer.setOption('showGutter',options.lineNumbers);
+            }
             editor.$blockScrolling = Infinity;
             if (options.value) {
                 session.setValue(options.value,-1);
diff --git a/editor/js/ui/tab-info.js b/editor/js/ui/tab-info.js
index d95cdca92..c054ee244 100644
--- a/editor/js/ui/tab-info.js
+++ b/editor/js/ui/tab-info.js
@@ -350,7 +350,8 @@ RED.sidebar.info = (function() {
         // tips.stop();
         sections.show();
         nodeSection.container.hide();
-        $(infoSection.content).html(html);
+        var wrapped = $('<div class="node-help"></div>').html(html);
+        $(infoSection.content).empty().append(wrapped);
     }
 
 
diff --git a/editor/sass/editor.scss b/editor/sass/editor.scss
index 837f355de..656b4c00c 100644
--- a/editor/sass/editor.scss
+++ b/editor/sass/editor.scss
@@ -48,8 +48,10 @@
 .editor-tray-body {
     position: relative;
     box-sizing: border-box;
-    form {
+    padding: 0.1px; // prevent margin collapsing
+    .dialog-form,#dialog-form, #dialog-config-form {
         margin: 20px;
+        height: calc(100% - 40px);
     }
 }
 .editor-tray-content {
@@ -154,7 +156,7 @@
 
 
 .dialog-form,#dialog-form, #dialog-config-form {
-    height: calc(100% - 20px);
+    height: 100%;
 }
 
 .input-error {
@@ -245,3 +247,48 @@
     font-size: 12px;
     line-height: 35px;
 }
+.node-input-expression-editor #dialog-form {
+    margin: 0;
+    height: 100%;
+    .red-ui-panel {
+        &:first-child {
+            padding: 20px 20px 0;
+        }
+        &:last-child {
+            padding-bottom: 20px;
+        }
+    }
+}
+.node-input-expression-tab-content {
+    position: relative;
+    padding: 0 20px;
+}
+
+#node-input-expression-help {
+    position: absolute;
+    top: 35px;
+    left:0;
+    right: 0;
+    bottom:0;
+    padding: 0 20px;
+    overflow: auto;
+    box-sizing: border-box;
+}
+#node-input-expression-panel-info {
+    & > .form-row {
+        margin: 0;
+        & > div:first-child {
+            margin-top: 10px;
+        }
+    }
+}
+.node-input-expression-legacy {
+    float: left;
+    cursor: pointer;
+    border: 1px solid white;
+    padding: 0 5px;
+    border-radius: 2px;
+    &:hover {
+        border-color: $primary-border-color;
+    }
+}
diff --git a/editor/sass/panels.scss b/editor/sass/panels.scss
new file mode 100644
index 000000000..ba803a8db
--- /dev/null
+++ b/editor/sass/panels.scss
@@ -0,0 +1,23 @@
+.red-ui-panels {
+    position: relative;
+
+    & > div {
+        // border: 1px solid red;
+        box-sizing: border-box;
+    }
+}
+
+.red-ui-panels-separator {
+    border-top: 1px solid $secondary-border-color;
+    border-bottom: 1px solid $secondary-border-color;
+    height: 7px;
+    box-sizing: border-box;
+    cursor: ns-resize;
+    background: $background-color url(images/grip.png) no-repeat 50% 50%;
+}
+
+
+.red-ui-panel {
+    overflow: auto;
+    height: calc(50% - 4px);
+}
diff --git a/editor/sass/style.scss b/editor/sass/style.scss
index c8022a6f8..5007396e1 100644
--- a/editor/sass/style.scss
+++ b/editor/sass/style.scss
@@ -37,6 +37,7 @@
 @import "library";
 @import "search";
 
+@import "panels";
 @import "tabs";
 @import "tab-config";
 @import "tab-info";
diff --git a/editor/templates/index.mst b/editor/templates/index.mst
index 0e92457d9..cc11bcd0f 100644
--- a/editor/templates/index.mst
+++ b/editor/templates/index.mst
@@ -166,22 +166,41 @@
 </script>
 
 <script type="text/x-red" data-template-name="_expression">
-    <div class="form-row" style="margin-bottom: 3px; text-align: right;">
-        <button id="node-input-expression-reformat" class="editor-button editor-button-small">format</button>
-    </div>
-    <div class="form-row node-text-editor-row">
-        <div style="height: 200px;min-height: 150px;" class="node-text-editor" id="node-input-expression"></div>
-    </div>
-    <div class="form-row">
-        <label for="node-input-expression-func" data-i18n="expressionEditor.functions"></label>
-        <select id="node-input-expression-func"></select>
-        <button id="node-input-expression-func-insert" class="editor-button" data-i18n="expressionEditor.insert"></button>
-        <div style="min-height: 200px;" id="node-input-expression-help"></div>
+    <div id="node-input-expression-panels">
+        <div id="node-input-expression-panel-expr" class="red-ui-panel">
+            <div class="form-row" style="margin-bottom: 3px; text-align: right;">
+                <span class="node-input-expression-legacy"><i class="fa fa-exclamation-circle"></i> <span data-i18n="expressionEditor.compatMode"></span></span>
+                <button id="node-input-expression-reformat" class="editor-button editor-button-small"><span data-i18n="expressionEditor.format"></span></button>
+            </div>
+            <div class="form-row node-text-editor-row">
+                <div class="node-text-editor" id="node-input-expression"></div>
+            </div>
+        </div>
+        <div id="node-input-expression-panel-info" class="red-ui-panel">
+            <div class="form-row">
+                <ul id="node-input-expression-tabs"></ul>
+                <div id="node-input-expression-tab-help" class="node-input-expression-tab-content hide">
+                    <div>
+                        <select id="node-input-expression-func"></select>
+                        <button id="node-input-expression-func-insert" class="editor-button" data-i18n="expressionEditor.insert"></button>
+                    </div>
+                    <div id="node-input-expression-help"></div>
+                </div>
+                <div id="node-input-expression-tab-test" class="node-input-expression-tab-content hide">
+                    <div>
+                        <span style="display: inline-block; width: calc(50% - 5px);" data-i18n="expressionEditor.data"></span>
+                        <span style="display: inline-block; width: calc(50% - 5px);" data-i18n="expressionEditor.result"></span>
+                    </div>
+                    <div style="display: inline-block; width: calc(50% - 5px);" class="node-text-editor" id="node-input-expression-test-data"></div>
+                    <div style="display: inline-block; width: calc(50% - 5px);" class="node-text-editor" id="node-input-expression-test-result"></div>
+                </div>
+            </div>
+        </div>
     </div>
 </script>
 <script type="text/x-red" data-template-name="_json">
     <div class="form-row" style="margin-bottom: 3px; text-align: right;">
-        <button id="node-input-expression-reformat" class="editor-button editor-button-small">format</button>
+        <button id="node-input-expression-reformat" class="editor-button editor-button-small"><span data-i18n="jsonEditor.format"></span></button>
     </div>
     <div class="form-row node-text-editor-row">
         <div style="height: 200px;min-height: 150px;" class="node-text-editor" id="node-input-json"></div>
diff --git a/editor/vendor/jsonata/formatter.js b/editor/vendor/jsonata/formatter.js
index 2ef4ecfb0..3210f7e74 100644
--- a/editor/vendor/jsonata/formatter.js
+++ b/editor/vendor/jsonata/formatter.js
@@ -111,11 +111,10 @@
         '$average':{ args:['value'] },
         '$boolean':{ args:['value'] },
         '$contains':{ args:['str','pattern']},
-        '$context': {args:['string']},
         '$count':{ args:['array'] },
         '$exists':{ args:['value'] },
-        '$flow': {args:['string']},
-        '$global': {args:['string']},
+        '$flowContext': {args:['string']},
+        '$globalContext': {args:['string']},
         '$join':{ args:['array','separator'] },
         '$keys':{ args:['object'] },
         '$length':{ args:['string'] },
diff --git a/nodes/core/locales/en-US/messages.json b/nodes/core/locales/en-US/messages.json
index 1bbf59d48..7202fd341 100644
--- a/nodes/core/locales/en-US/messages.json
+++ b/nodes/core/locales/en-US/messages.json
@@ -519,7 +519,7 @@
             "else":"otherwise"
         },
         "errors": {
-            "invalid-expr": "Invalid expression: __error__"
+            "invalid-expr": "Invalid JSONata expression: __error__"
         }
     },
     "change": {
@@ -544,7 +544,8 @@
         },
         "errors": {
             "invalid-from": "Invalid 'from' property: __error__",
-            "invalid-json": "Invalid 'to' JSON property"
+            "invalid-json": "Invalid 'to' JSON property",
+            "invalid-expr": "Invalid JSONata expression: __error__"
         }
     },
     "range": {
diff --git a/nodes/core/logic/10-switch.js b/nodes/core/logic/10-switch.js
index 4cd1b6151..95df6661e 100644
--- a/nodes/core/logic/10-switch.js
+++ b/nodes/core/logic/10-switch.js
@@ -104,7 +104,7 @@ module.exports = function(RED) {
             try {
                 var prop;
                 if (node.propertyType === 'jsonata') {
-                    prop = node.property.evaluate({msg:msg});
+                    prop = RED.util.evaluateJSONataExpression(node.property,msg);
                 } else {
                     prop = RED.util.evaluateNodeProperty(node.property,node.propertyType,node,msg);
                 }
@@ -117,7 +117,7 @@ module.exports = function(RED) {
                         v1 = node.previousValue;
                     } else if (rule.vt === 'jsonata') {
                         try {
-                            v1 = rule.v.evaluate({msg:msg});
+                            v1 = RED.util.evaluateJSONataExpression(rule.v,msg);
                         } catch(err) {
                             node.error(RED._("switch.errors.invalid-expr",{error:err.message}));
                             return;
@@ -134,7 +134,7 @@ module.exports = function(RED) {
                         v2 = node.previousValue;
                     } else if (rule.v2t === 'jsonata') {
                         try {
-                            v2 = rule.v2.evaluate({msg:msg});
+                            v2 = RED.util.evaluateJSONataExpression(rule.v2,msg);
                         } catch(err) {
                             node.error(RED._("switch.errors.invalid-expr",{error:err.message}));
                             return;
diff --git a/nodes/core/logic/15-change.js b/nodes/core/logic/15-change.js
index fc28337b2..dda8bfb97 100644
--- a/nodes/core/logic/15-change.js
+++ b/nodes/core/logic/15-change.js
@@ -19,6 +19,7 @@ module.exports = function(RED) {
 
     function ChangeNode(n) {
         RED.nodes.createNode(this, n);
+        var node = this;
 
         this.rules = n.rules;
         var rule;
@@ -90,7 +91,7 @@ module.exports = function(RED) {
                     rule.to = RED.util.prepareJSONataExpression(rule.to,this);
                 } catch(e) {
                     valid = false;
-                    this.error(RED._("change.errors.invalid-from",{error:e.message}));
+                    this.error(RED._("change.errors.invalid-expr",{error:e.message}));
                 }
             }
         }
@@ -115,7 +116,12 @@ module.exports = function(RED) {
                 } else if (rule.tot === 'date') {
                     value = Date.now();
                 } else if (rule.tot === 'jsonata') {
-                    value = rule.to.evaluate({msg:msg});
+                    try{
+                        value = RED.util.evaluateJSONataExpression(rule.to,msg);
+                    } catch(err) {
+                        node.error(RED._("change.errors.invalid-expr",{error:err.message}));
+                        return;
+                    }
                 }
                 if (rule.t === 'change') {
                     if (rule.fromt === 'msg' || rule.fromt === 'flow' || rule.fromt === 'global') {
@@ -219,7 +225,6 @@ module.exports = function(RED) {
             return msg;
         }
         if (valid) {
-            var node = this;
             this.on('input', function(msg) {
                 for (var i=0; i<this.rules.length; i++) {
                     if (this.rules[i].t === "move") {
diff --git a/red/api/locales/en-US/editor.json b/red/api/locales/en-US/editor.json
index a0723b4e0..39cdbd6a2 100644
--- a/red/api/locales/en-US/editor.json
+++ b/red/api/locales/en-US/editor.json
@@ -398,9 +398,15 @@
     "expressionEditor": {
         "functions": "Functions",
         "insert": "Insert",
-        "title": "JSONata Expression editor"
+        "title": "JSONata Expression editor",
+        "data": "Example message",
+        "result": "Result",
+        "format": "format expression",
+        "compatMode": "Compatibility mode enabled",
+        "compatModeDesc": "<h3>JSONata compatibility mode</h3><p> The current expression appears to still reference <code>msg</code> so will be evaluated in compatibility mode. Please update the expression to not use <code>msg</code> as this mode will be removed in the future.</p><p> When JSONata support was first added to Node-RED, it required the expression to reference the <code>msg</code> object. For example <code>msg.payload</code> would be used to access the payload.</p><p> That is no longer necessary as the expression will be evaluated against the message directly. To access the payload, the expression should be just <code>payload</code>.</p>"
     },
     "jsonEditor": {
-        "title": "JSON editor"
+        "title": "JSON editor",
+        "format": "format JSON"
     }
 }
diff --git a/red/api/locales/en-US/jsonata.json b/red/api/locales/en-US/jsonata.json
index d7ce59c91..aff5a6e56 100644
--- a/red/api/locales/en-US/jsonata.json
+++ b/red/api/locales/en-US/jsonata.json
@@ -110,16 +110,11 @@
         "args": "object",
         "desc": "Splits an object containing key/value pairs into an array of objects, each of which has a single key/value pair from the input object. If the parameter is an array of objects, then the resultant array contains an object for every key/value pair in every object in the supplied array."
     },
-
-    "$context": {
-        "args": "string",
-        "desc": "Retrieves a node context property."
-    },
-    "$flow": {
+    "$flowContext": {
         "args": "string",
         "desc": "Retrieves a flow context property."
     },
-    "$global": {
+    "$globalContext": {
         "args": "string",
         "desc": "Retrieves a global context property."
     }
diff --git a/red/runtime/util.js b/red/runtime/util.js
index 921f7e521..30bb2e259 100644
--- a/red/runtime/util.js
+++ b/red/runtime/util.js
@@ -323,25 +323,33 @@ function evaluateNodeProperty(value, type, node, msg) {
     } else if (type === 'bool') {
         return /^true$/i.test(value);
     } else if (type === 'jsonata') {
-        return prepareJSONataExpression(value,node).evaluate({msg:msg});
+        var expr = prepareJSONataExpression(value,node);
+        return evaluateJSONataExpression(expr,msg);
     }
     return value;
 }
 
 function prepareJSONataExpression(value,node) {
     var expr = jsonata(value);
-    expr.assign('context',function(val) {
-        return node.context().get(val);
-    });
-    expr.assign('flow',function(val) {
+    expr.assign('flowContext',function(val) {
         return node.context().flow.get(val);
     });
-    expr.assign('global',function(val) {
+    expr.assign('globalContext',function(val) {
         return node.context().global(val);
     });
+    expr._legacyMode = /(^|[^a-zA-Z0-9_'"])msg([^a-zA-Z0-9_'"]|$)/.test(value);
     return expr;
 }
 
+function evaluateJSONataExpression(expr,msg) {
+    var context = msg;
+    if (expr._legacyMode) {
+        context = {msg:msg};
+    }
+    return expr.evaluate(context);
+}
+
+
 function normaliseNodeTypeName(name) {
     var result = name.replace(/[^a-zA-Z0-9]/g, " ");
     result = result.trim();
@@ -366,5 +374,6 @@ module.exports = {
     evaluateNodeProperty: evaluateNodeProperty,
     normalisePropertyExpression: normalisePropertyExpression,
     normaliseNodeTypeName: normaliseNodeTypeName,
-    prepareJSONataExpression: prepareJSONataExpression
+    prepareJSONataExpression: prepareJSONataExpression,
+    evaluateJSONataExpression: evaluateJSONataExpression
 };