From 51056c4b580f88d0dcba7e18ef8b452d34e100ca Mon Sep 17 00:00:00 2001
From: Dimitris - Rafail Katsampas <katsampasdr@gmail.com>
Date: Fri, 7 Jan 2022 00:16:52 +0000
Subject: [PATCH 1/3] fix: Converter callbacks should have caller as context.

---
 .../ui/core/bindable/bindable-expressions.ts  | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/packages/core/ui/core/bindable/bindable-expressions.ts b/packages/core/ui/core/bindable/bindable-expressions.ts
index e3a903119a..785ff7ba49 100644
--- a/packages/core/ui/core/bindable/bindable-expressions.ts
+++ b/packages/core/ui/core/bindable/bindable-expressions.ts
@@ -82,20 +82,23 @@ const expressionParsers = {
 			object = getContext(expression.callee.name, model, changedModel);
 			property = expression.callee?.name;
 		}
+
 		const callback = expression.callee.optional ? object?.[property] : object[property];
+		if (isNullOrUndefined(callback)) {
+			throw new Error('Cannot perform a call using a null or undefined property');
+		}
+
 		const isConverter = isObject(callback) && (isFunction(callback.toModel) || isFunction(callback.toView));
+		if (!isFunction(callback) && !isConverter) {
+			throw new Error('Cannot perform a call using a non-callable property');
+		}
 
 		const parsedArgs = [];
 		for (let argument of expression.arguments) {
 			let value = convertExpressionToValue(argument, model, isBackConvert, changedModel);
 			argument.type == 'SpreadElement' ? parsedArgs.push(...value) : parsedArgs.push(value);
 		}
-
-		if (isNullOrUndefined(callback) || (!isFunction(callback) && !isConverter)) {
-			throw new Error('Cannot perform a call using a non-function property');
-		}
-
-		return isConverter ? getConverter(callback, parsedArgs, isBackConvert) : callback.apply(object, parsedArgs);
+		return isConverter ? getConverter(callback, object, parsedArgs, isBackConvert) : callback.apply(object, parsedArgs);
 	},
 	'ChainExpression': (expression: ASTExpression, model, isBackConvert: boolean, changedModel) => {
 		return convertExpressionToValue(expression.expression, model, isBackConvert, changedModel);
@@ -177,9 +180,9 @@ function getContext(key, model, changedModel) {
 	return key in changedModel ? changedModel : model;
 }
 
-function getConverter(context, args, isBackConvert: boolean) {
+function getConverter(converterSchema, context, args, isBackConvert: boolean) {
 	const converter = { callback: null, context, args };
-	let callback = isBackConvert ? context.toModel : context.toView;
+	let callback = isBackConvert ? converterSchema.toModel : converterSchema.toView;
 	if (callback == null) {
 		callback = Function.prototype;
 	}

From c89b662d864c03d08d21934e77fe4d3ec685ff27 Mon Sep 17 00:00:00 2001
From: Dimitris - Rafail Katsampas <katsampasdr@gmail.com>
Date: Fri, 7 Jan 2022 20:52:03 +0000
Subject: [PATCH 2/3] fix: Check `global` context for indentifiers too.

---
 packages/core/ui/core/bindable/bindable-expressions.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/core/ui/core/bindable/bindable-expressions.ts b/packages/core/ui/core/bindable/bindable-expressions.ts
index 785ff7ba49..90072fe66b 100644
--- a/packages/core/ui/core/bindable/bindable-expressions.ts
+++ b/packages/core/ui/core/bindable/bindable-expressions.ts
@@ -177,7 +177,11 @@ const expressionParsers = {
 };
 
 function getContext(key, model, changedModel) {
-	return key in changedModel ? changedModel : model;
+	let context = key in changedModel ? changedModel : model;
+	if (!context && key in global) {
+		context = global;
+	}
+	return context;
 }
 
 function getConverter(converterSchema, context, args, isBackConvert: boolean) {

From 9c5b74168cf56ab691f1b1b40ecfd12a30ed5dfd Mon Sep 17 00:00:00 2001
From: Dimitris - Rafail Katsampas <katsampasdr@gmail.com>
Date: Fri, 7 Jan 2022 21:21:35 +0000
Subject: [PATCH 3/3] fix: Bad context check for `Identifier` expressions.

---
 packages/core/ui/core/bindable/bindable-expressions.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/core/ui/core/bindable/bindable-expressions.ts b/packages/core/ui/core/bindable/bindable-expressions.ts
index 90072fe66b..c1450e05dc 100644
--- a/packages/core/ui/core/bindable/bindable-expressions.ts
+++ b/packages/core/ui/core/bindable/bindable-expressions.ts
@@ -178,7 +178,7 @@ const expressionParsers = {
 
 function getContext(key, model, changedModel) {
 	let context = key in changedModel ? changedModel : model;
-	if (!context && key in global) {
+	if (!(key in context)) {
 		context = global;
 	}
 	return context;