3 files changed, 40 insertions, 11 deletions

diff --git a/src/new_fields/Doc.ts b/src/new_fields/Doc.ts
index 9bacf49ba..cce4fff5d 100644
--- a/src/new_fields/Doc.ts
+++ b/src/new_fields/Doc.ts
@@ -2,7 +2,7 @@ import { observable, action } from "mobx";
 import { serializable, primitive, map, alias, list } from "serializr";
 import { autoObject, SerializationHelper, Deserializable } from "../client/util/SerializationHelper";
 import { DocServer } from "../client/DocServer";
-import { setter, getter, getField, updateFunction, deleteProperty } from "./util";
+import { setter, getter, getField, updateFunction, deleteProperty, makeEditable, makeReadOnly } from "./util";
 import { Cast, ToConstructor, PromiseValue, FieldValue, NumCast } from "./Types";
 import { listSpec } from "./Schema";
 import { ObjectField } from "./ObjectField";
@@ -156,6 +156,15 @@ export namespace Doc {
     //         return Cast(field, ctor);
     //     });
     // }
+    export function MakeReadOnly(): { end(): void } {
+        makeReadOnly();
+        return {
+            end() {
+                makeEditable();
+            }
+        };
+    }
+
     export function Get(doc: Doc, key: string, ignoreProto: boolean = false): FieldResult {
         const self = doc[Self];
         return getField(self, key, ignoreProto);
diff --git a/src/new_fields/Proxy.ts b/src/new_fields/Proxy.ts
index 130ec066e..38d874a68 100644
--- a/src/new_fields/Proxy.ts
+++ b/src/new_fields/Proxy.ts
@@ -48,9 +48,8 @@ export class ProxyField<T extends RefField> extends ObjectField {
     private failed = false;
     private promise?: Promise<any>;
 
-    value(callback?: ((field: T | undefined) => void)): T | undefined | FieldWaiting {
+    value(): T | undefined | FieldWaiting {
         if (this.cache) {
-            callback && callback(this.cache);
             return this.cache;
         }
         if (this.failed) {
@@ -64,7 +63,6 @@ export class ProxyField<T extends RefField> extends ObjectField {
                 return field;
             }));
         }
-        callback && this.promise.then(callback);
         return this.promise;
     }
 }
diff --git a/src/new_fields/util.ts b/src/new_fields/util.ts
index 8cb1db953..cc937c567 100644
--- a/src/new_fields/util.ts
+++ b/src/new_fields/util.ts
@@ -6,10 +6,13 @@ import { FieldValue } from "./Types";
 import { RefField } from "./RefField";
 import { ObjectField } from "./ObjectField";
 import { action } from "mobx";
-import { Parent, OnUpdate, Update, Id, SelfProxy } from "./FieldSymbols";
+import { Parent, OnUpdate, Update, Id, SelfProxy, Self } from "./FieldSymbols";
 import { ComputedField } from "../fields/ScriptField";
 
-export const setter = action(function (target: any, prop: string | symbol | number, value: any, receiver: any): boolean {
+function _readOnlySetter(): never {
+    throw new Error("Documents can't be modified in read-only mode");
+}
+const _setterImpl = action(function (target: any, prop: string | symbol | number, value: any, receiver: any): boolean {
     if (SerializationHelper.IsSerializing()) {
         target[prop] = value;
         return true;
@@ -53,6 +56,20 @@ export const setter = action(function (target: any, prop: string | symbol | numb
     return true;
 });
 
+let _setter: (target: any, prop: string | symbol | number, value: any, receiver: any) => boolean = _setterImpl;
+
+export function makeReadOnly() {
+    _setter = _readOnlySetter;
+}
+
+export function makeEditable() {
+    _setter = _setterImpl;
+}
+
+export function setter(target: any, prop: string | symbol | number, value: any, receiver: any): boolean {
+    return _setter(target, prop, value, receiver);
+}
+
 export function getter(target: any, prop: string | symbol | number, receiver: any): any {
     if (typeof prop === "symbol") {
         return target.__fields[prop] || target[prop];
@@ -60,25 +77,30 @@ export function getter(target: any, prop: string | symbol | number, receiver: an
     if (SerializationHelper.IsSerializing()) {
         return target[prop];
     }
-    return getField(target, prop);
+    return getFieldImpl(target, prop, receiver);
 }
 
-export function getField(target: any, prop: string | number, ignoreProto: boolean = false): any {
+function getFieldImpl(target: any, prop: string | number, receiver: any, ignoreProto: boolean = false): any {
+    receiver = receiver || target[SelfProxy];
     const field = target.__fields[prop];
     if (field instanceof ProxyField) {
         return field.value();
     }
     if (field instanceof ComputedField) {
-        return field.value;
+        return field.value(receiver);
     }
     if (field === undefined && !ignoreProto && prop !== "proto") {
-        const proto = getField(target, "proto", true);
+        const proto = getFieldImpl(target, "proto", receiver, true);//TODO tfs: instead of receiver we could use target[SelfProxy]... I don't which semantics we want or if it really matters
         if (proto instanceof Doc) {
-            return proto[prop];
+            return getFieldImpl(proto[Self], prop, receiver, ignoreProto);
         }
         return undefined;
     }
     return field;
+
+}
+export function getField(target: any, prop: string | number, ignoreProto: boolean = false): any {
+    return getFieldImpl(target, prop, undefined, ignoreProto);
 }
 
 export function deleteProperty(target: any, prop: string | number | symbol) {