diff --git a/editor/js/ui/typedInput.js b/editor/js/ui/typedInput.js
index a02a39998..758bb51c8 100644
--- a/editor/js/ui/typedInput.js
+++ b/editor/js/ui/typedInput.js
@@ -14,10 +14,79 @@
  * limitations under the License.
  **/
 (function($) {
+    function validateExpression(str) {
+        var length = str.length;
+        var start = 0;
+        var inString = false;
+        var inBox = false;
+        var quoteChar;
+        var v;
+        for (var i=0;i<length;i++) {
+            var c = str[i];
+            if (!inString) {
+                if (c === "'" || c === '"') {
+                    if (!inBox) {
+                        return false;
+                    }
+                    inString = true;
+                    quoteChar = c;
+                    start = i+1;
+                } else if (c === '.') {
+                    if (i===length-1) {
+                        return false;
+                    }
+                    // Next char is a-z
+                    if (!/[a-z0-9]/i.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                } else if (c === '[') {
+                    if (i === 0) {
+                        return false;
+                    }
+                    if (i===length-1) {
+                        return false;
+                    }
+                    // Next char is either a quote or a number
+                    if (!/["'\d]/.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                    inBox = true;
+                } else if (c === ']') {
+                    if (!inBox) {
+                        return false;
+                    }
+                    if (start != i) {
+                        v = str.substring(start,i);
+                        if (!/^\d+$/.test(v)) {
+                            return false;
+                        }
+                    }
+                    start = i+1;
+                    inBox = false;
+                }
+            } else {
+                if (c === quoteChar) {
+                    // Next char must be a ]
+                    if (!/\]/.test(str[i+1])) {
+                        return false;
+                    }
+                    start = i+1;
+                    inString = false;
+                }
+            }
+
+        }
+        if (inBox || inString) {
+            return false;
+        }
+        return true;
+    }
     var allOptions = {
-        msg: {value:"msg",label:"msg.",validate:/^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]+)*/i},
-        flow: {value:"flow",label:"flow.",validate:/^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]+)*/i},
-        global: {value:"global",label:"global.",validate:/^[a-zA-Z_][a-zA-Z0-9_]*(\.[a-zA-Z_][a-zA-Z0-9_]+)*/i},
+        msg: {value:"msg",label:"msg.",validate:validateExpression},
+        flow: {value:"flow",label:"flow.",validate:validateExpression},
+        global: {value:"global",label:"global.",validate:validateExpression},
         str: {value:"str",label:"string",icon:"red/images/typedInput/az.png"},
         num: {value:"num",label:"number",icon:"red/images/typedInput/09.png",validate:/^[+-]?[0-9]*\.?[0-9]*([eE][-+]?[0-9]+)?$/},
         bool: {value:"bool",label:"boolean",icon:"red/images/typedInput/bool.png",options:["true","false"]},
diff --git a/red/runtime/util.js b/red/runtime/util.js
index 9850b2fd1..807375e6f 100644
--- a/red/runtime/util.js
+++ b/red/runtime/util.js
@@ -127,14 +127,103 @@ function compareObjects(obj1,obj2) {
     return true;
 }
 
+function normalisePropertyExpression(str) {
+    var length = str.length;
+    var parts = [];
+    var start = 0;
+    var inString = false;
+    var inBox = false;
+    var quoteChar;
+    var v;
+    for (var i=0;i<length;i++) {
+        var c = str[i];
+        if (!inString) {
+            if (c === "'" || c === '"') {
+                if (!inBox) {
+                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                }
+                inString = true;
+                quoteChar = c;
+                start = i+1;
+            } else if (c === '.') {
+                if (start != i) {
+                    v = str.substring(start,i);
+                    if (/^\d+$/.test(v)) {
+                        parts.push(parseInt(v));
+                    } else {
+                        parts.push(v);
+                    }
+                }
+                if (i===length-1) {
+                    throw new Error("Invalid property expression: unterminated expression");
+                }
+                // Next char is a-z
+                if (!/[a-z0-9]/i.test(str[i+1])) {
+                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
+                }
+                start = i+1;
+            } else if (c === '[') {
+                if (i === 0) {
+                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                }
+                if (start != i) {
+                    parts.push(str.substring(start,i));
+                }
+                if (i===length-1) {
+                    throw new Error("Invalid property expression: unterminated expression");
+                }
+                // Next char is either a quote or a number
+                if (!/["'\d]/.test(str[i+1])) {
+                    throw new Error("Invalid property expression: unexpected "+str[i+1]+" at position "+(i+1));
+                }
+                start = i+1;
+                inBox = true;
+            } else if (c === ']') {
+                if (!inBox) {
+                    throw new Error("Invalid property expression: unexpected "+c+" at position "+i);
+                }
+                if (start != i) {
+                    v = str.substring(start,i);
+                    if (/^\d+$/.test(v)) {
+                        parts.push(parseInt(v));
+                    } else {
+                        throw new Error("Invalid property expression: unexpected array expression at position "+start);
+                    }
+                }
+                start = i+1;
+                inBox = false;
+            }
+        } else {
+            if (c === quoteChar) {
+                parts.push(str.substring(start,i));
+                // Next char must be a ]
+                if (!/\]/.test(str[i+1])) {
+                    throw new Error("Invalid property expression: unexpected array expression at position "+start);
+                }
+                start = i+1;
+                inString = false;
+            }
+        }
+
+    }
+    if (inBox || inString) {
+        throw new Error("Invalid property expression: unterminated expression");
+    }
+    if (start < length) {
+        parts.push(str.substring(start));
+    }
+    return parts;
+}
+
 function getMessageProperty(msg,expr) {
     var result = null;
     if (expr.indexOf('msg.')===0) {
         expr = expr.substring(4);
     }
-    var msgPropParts = expr.split(".");
-    msgPropParts.reduce(function(obj, i) {
-        result = (typeof obj[i] !== "undefined" ? obj[i] : undefined);
+    var msgPropParts = normalisePropertyExpression(expr);
+    var m;
+    msgPropParts.reduce(function(obj, key) {
+        result = (typeof obj[key] !== "undefined" ? obj[key] : undefined);
         return result;
     }, msg);
     return result;
@@ -147,30 +236,54 @@ function setMessageProperty(msg,prop,value,createMissing) {
     if (prop.indexOf('msg.')===0) {
         prop = prop.substring(4);
     }
-    var msgPropParts = prop.split(".");
+    var msgPropParts = normalisePropertyExpression(prop);
     var depth = 0;
-    msgPropParts.reduce(function(obj, i) {
-        if (obj === null) {
-            return null;
-        }
-        depth++;
-        if (depth === msgPropParts.length) {
-            if (typeof value === "undefined") {
-                delete obj[i];
-            } else {
-                obj[i] = value;
-            }
-        } else {
-            if (!obj[i]) {
-                if (createMissing) {
-                    obj[i] = {};
+    var length = msgPropParts.length;
+    var obj = msg;
+    var key;
+    for (var i=0;i<length-1;i++) {
+        key = msgPropParts[i];
+        if (typeof key === 'string' || (typeof key === 'number' && !Array.isArray(obj))) {
+            if (obj.hasOwnProperty(key)) {
+                obj = obj[key];
+            } else if (createMissing) {
+                if (typeof msgPropParts[i+1] === 'string') {
+                    obj[key] = {};
                 } else {
-                    return null;
+                    obj[key] = [];
                 }
+                obj = obj[key];
+            } else {
+                return null;
+            }
+        } else if (typeof key === 'number') {
+            // obj is an array
+            if (obj[key] === undefined) {
+                if (createMissing) {
+                    if (typeof msgPropParts[i+1] === 'string') {
+                        obj[key] = {};
+                    } else {
+                        obj[key] = [];
+                    }
+                    obj = obj[key];
+                } else {
+                    return null
+                }
+            } else {
+                obj = obj[key];
             }
-            return obj[i];
         }
-    }, msg);
+    }
+    key = msgPropParts[length-1];
+    if (typeof value === "undefined") {
+        if (typeof key === 'number' && Array.isArray(obj)) {
+            obj.splice(key,1);
+        } else {
+            delete obj[key]
+        }
+    } else {
+        obj[key] = value;
+    }
 }
 
 function evaluateNodeProperty(value, type, node, msg) {
@@ -205,5 +318,6 @@ module.exports = {
     generateId: generateId,
     getMessageProperty: getMessageProperty,
     setMessageProperty: setMessageProperty,
-    evaluateNodeProperty: evaluateNodeProperty
+    evaluateNodeProperty: evaluateNodeProperty,
+    normalisePropertyExpression: normalisePropertyExpression
 };
diff --git a/test/red/runtime/util_spec.js b/test/red/runtime/util_spec.js
index 51fb11c1e..3aad44418 100644
--- a/test/red/runtime/util_spec.js
+++ b/test/red/runtime/util_spec.js
@@ -58,6 +58,7 @@ describe("red/util", function() {
         it('Buffer', function() {
             util.compareObjects(new Buffer("hello"),new Buffer("hello")).should.equal(true);
             util.compareObjects(new Buffer("hello"),new Buffer("hello ")).should.equal(false);
+            util.compareObjects(new Buffer("hello"),"hello").should.equal(false);
         });
 
     });
@@ -157,7 +158,16 @@ describe("red/util", function() {
             (function() {
                 util.getMessageProperty({a:"foo"},"msg.a.b.c");
             }).should.throw();
-        })
+        });
+        it('retrieves a property with array syntax', function() {
+            var v = util.getMessageProperty({a:["foo","bar"]},"msg.a[0]");
+            v.should.eql("foo");
+            var v2 = util.getMessageProperty({a:[null,{b:"foo"}]},"a[1].b");
+            v2.should.eql("foo");
+            var v3 = util.getMessageProperty({a:[[["foo"]]]},"a[0][0][0]");
+            v3.should.eql("foo");
+        });
+
     });
 
     describe('setMessageProperty', function() {
@@ -190,7 +200,48 @@ describe("red/util", function() {
             var msg = {a:{}};
             util.setMessageProperty(msg,"msg.a.b.c",undefined);
             should.not.exist(msg.a.b);
+        });
+        it('sets a property with array syntax', function() {
+            var msg = {a:{b:["foo",{c:["",""]}]}};
+            util.setMessageProperty(msg,"msg.a.b[1].c[1]","bar");
+            msg.a.b[1].c[1].should.eql('bar');
+        });
+        it('creates missing array elements - final property', function() {
+            var msg = {a:[]};
+            util.setMessageProperty(msg,"msg.a[2]","bar");
+            msg.a.should.have.length(3);
+            msg.a[2].should.eql("bar");
+        });
+        it('creates missing array elements - mid property', function() {
+            var msg = {};
+            util.setMessageProperty(msg,"msg.a[2].b","bar");
+            msg.a.should.have.length(3);
+            msg.a[2].b.should.eql("bar");
+        });
+        it('creates missing array elements - multi-arrays', function() {
+            var msg = {};
+            util.setMessageProperty(msg,"msg.a[2][2]","bar");
+            msg.a.should.have.length(3);
+            msg.a.should.be.instanceOf(Array);
+            msg.a[2].should.have.length(3);
+            msg.a[2].should.be.instanceOf(Array);
+            msg.a[2][2].should.eql("bar");
+        });
+        it('does not create missing array elements - final property', function() {
+            var msg = {a:{}};
+            util.setMessageProperty(msg,"msg.a.b[2]","bar",false);
+            should.not.exist(msg.a.b);
+            // check it has not been misinterpreted
+            msg.a.should.not.have.property("b[2]");
+        });
+        it('deletes property inside array if value is undefined', function() {
+            var msg = {a:[1,2,3]};
+            util.setMessageProperty(msg,"msg.a[1]",undefined);
+            msg.a.should.have.length(2);
+            msg.a[0].should.eql(1);
+            msg.a[1].should.eql(3);
         })
+
     });
 
     describe('evaluateNodeProperty', function() {
@@ -210,6 +261,16 @@ describe("red/util", function() {
             var result = util.evaluateNodeProperty('^abc$','re');
             result.toString().should.eql("/^abc$/");
         });
+        it('returns boolean',function() {
+            var result = util.evaluateNodeProperty('true','bool');
+            result.should.be.true();
+            result = util.evaluateNodeProperty('TrUe','bool');
+            result.should.be.true();
+            result = util.evaluateNodeProperty('false','bool');
+            result.should.be.false();
+            result = util.evaluateNodeProperty('','bool');
+            result.should.be.false();
+        });
         it('returns date',function() {
             var result = util.evaluateNodeProperty('','date');
             (Date.now() - result).should.be.approximately(0,50);
@@ -246,7 +307,45 @@ describe("red/util", function() {
             },{});
             result.should.eql("123");
         });
+    });
 
+    describe('normalisePropertyExpression', function() {
+        function testABC(input,expected) {
+            var result = util.normalisePropertyExpression(input);
+            // console.log("+",input);
+            // console.log(result);
+            result.should.eql(expected);
+        }
 
-    })
+        function testInvalid(input) {
+            /*jshint immed: false */
+            (function() {
+                util.normalisePropertyExpression(input);
+            }).should.throw();
+        }
+        it('pass a.b.c',function() { testABC('a.b.c',['a','b','c']); })
+        it('pass a["b"]["c"]',function() { testABC('a["b"]["c"]',['a','b','c']); })
+        it('pass a["b"].c',function() { testABC('a["b"].c',['a','b','c']); })
+        it("pass a['b'].c",function() { testABC("a['b'].c",['a','b','c']); })
+
+        it("pass a[0].c",function() { testABC("a[0].c",['a',0,'c']); })
+        it("pass a.0.c",function() { testABC("a.0.c",['a',0,'c']); })
+        it("pass a['a.b[0]'].c",function() { testABC("a['a.b[0]'].c",['a','a.b[0]','c']); })
+        it("pass a[0][0][0]",function() { testABC("a[0][0][0]",['a',0,0,0]); })
+
+        it("fail a'b'.c",function() { testInvalid("a'b'.c"); })
+        it("fail a['b'.c",function() { testInvalid("a['b'.c"); })
+        it("fail a[]",function() { testInvalid("a[]"); })
+        it("fail a]",function() { testInvalid("a]"); })
+        it("fail a[",function() { testInvalid("a["); })
+        it("fail a[0d]",function() { testInvalid("a[0d]"); })
+        it("fail a['",function() { testInvalid("a['"); })
+        it("fail a[']",function() { testInvalid("a[']"); })
+        it("fail a[0']",function() { testInvalid("a[0']"); })
+        it("fail a.[0]",function() { testInvalid("a.[0]"); })
+        it("fail [0]",function() { testInvalid("[0]"); })
+        it("fail a[0",function() { testInvalid("a[0"); })
+        it("fail a.",function() { testInvalid("a."); })
+        it("fail a[0].[1]",function() { testInvalid("a[0].[1]"); })
+    });
 });