From 2a7ecc8e179a8020c291da9ed84c877402dbd2f9 Mon Sep 17 00:00:00 2001
From: Hannah Chow <hannah_chow@brown.edu>
Date: Thu, 7 Mar 2019 01:11:32 -0500
Subject: delete working

---
 src/fields/Document.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'src/fields')

diff --git a/src/fields/Document.ts b/src/fields/Document.ts
index 2e873439c..25e239417 100644
--- a/src/fields/Document.ts
+++ b/src/fields/Document.ts
@@ -1,6 +1,6 @@
 import { Key } from "./Key"
 import { KeyStore } from "./KeyStore";
-import { Field, Cast, FieldWaiting, FieldValue, FieldId } from "./Field"
+import { Field, Cast, FieldWaiting, FieldValue, FieldId, Opt } from "./Field"
 import { NumberField } from "./NumberField";
 import { ObservableMap, computed, action } from "mobx";
 import { TextField } from "./TextField";
@@ -128,6 +128,12 @@ export class Document extends Field {
         return false;
     }
 
+    GetTAsync<T extends Field>(key: Key, ctor: { new(): T }, callback: (field: Opt<T>) => void): boolean {
+        return this.GetAsync(key, (field) => {
+            callback(Cast(field, ctor));
+        })
+    }
+
     /**
      * Same as {@link Document#GetAsync}, except a field of the given type
      * will be created if there is no field associated with the given key,
-- 
cgit v1.2.3-70-g09d2