2 files changed, 37 insertions, 1 deletions
diff --git a/src/new_fields/Doc.ts b/src/new_fields/Doc.ts
index bd10e5474..79e5a156d 100644
--- a/src/new_fields/Doc.ts
+++ b/src/new_fields/Doc.ts
@@ -5,6 +5,9 @@ import { Utils } from "../Utils";
 import { DocServer } from "../client/DocServer";
 import { setter, getter, getField } from "./util";
 import { Cast, ToConstructor, PromiseValue, FieldValue } from "./Types";
+import { UndoManager, undoBatch } from "../client/util/UndoManager";
+import { listSpec } from "./Schema";
+import { List } from "./List";
 
 export type FieldId = string;
 export const HandleUpdate = Symbol("HandleUpdate");
@@ -54,7 +57,7 @@ export class Doc extends RefField {
         return doc;
     }
 
-    proto: FieldResult<Doc>;
+    proto: Opt<Doc>;
     [key: string]: FieldResult;
 
     @serializable(alias("fields", map(autoObject())))
@@ -126,6 +129,31 @@ export namespace Doc {
         return alias;
     }
 
+    export function MakeLink(source: Doc, target: Doc): Doc {
+        let linkDoc = new Doc;
+        UndoManager.RunInBatch(() => {
+            linkDoc.title = "New Link";
+            linkDoc.linkDescription = "";
+            linkDoc.linkTags = "Default";
+
+            linkDoc.linkedTo = target;
+            linkDoc.linkedFrom = source;
+
+            let linkedFrom = Cast(target.linkedFromDocs, listSpec(Doc));
+            if (!linkedFrom) {
+                target.linkedFromDocs = linkedFrom = new List<Doc>();
+            }
+            linkedFrom.push(linkDoc);
+
+            let linkedTo = Cast(source.linkedToDocs, listSpec(Doc));
+            if (!linkedTo) {
+                source.linkedToDocs = linkedTo = new List<Doc>();
+            }
+            linkedTo.push(linkDoc);
+        }, "make link");
+        return linkDoc;
+    }
+
     export function MakeDelegate(doc: Doc): Doc;
     export function MakeDelegate(doc: Opt<Doc>): Opt<Doc>;
     export function MakeDelegate(doc: Opt<Doc>): Opt<Doc> {
diff --git a/src/new_fields/Types.ts b/src/new_fields/Types.ts
index 4ad8dcade..079c7b76d 100644
--- a/src/new_fields/Types.ts
+++ b/src/new_fields/Types.ts
@@ -59,6 +59,14 @@ export function Cast<T extends ToConstructor<Field> | ListSpec<Field>>(field: Fi
     return defaultVal;
 }
 
+export function NumCast(field: FieldResult, defaultVal: Opt<number> = 0) {
+    return Cast(field, "number", defaultVal);
+}
+
+export function StrCast(field: FieldResult, defaultVal: Opt<string> = "") {
+    return Cast(field, "string", defaultVal);
+}
+
 type WithoutList<T extends Field> = T extends List<infer R> ? R[] : T;
 
 export function FieldValue<T extends Field, U extends WithoutList<T>>(field: Opt<T> | Promise<Opt<T>>, defaultValue: U): WithoutList<T>;