1 files changed, 21 insertions, 0 deletions
diff --git a/src/new_fields/Doc.ts b/src/new_fields/Doc.ts
index b0184dd4e..27dcfba08 100644
--- a/src/new_fields/Doc.ts
+++ b/src/new_fields/Doc.ts
@@ -280,6 +280,27 @@ export namespace Doc {
         return new Doc;
     }
 
+    export function expandTemplateLayout(templateLayoutDoc: Doc, dataDoc?: Doc) {
+        let resolvedDataDoc = (templateLayoutDoc !== dataDoc) ? dataDoc : undefined;
+        if (!dataDoc || !(templateLayoutDoc && !(Cast(templateLayoutDoc.layout, Doc) instanceof Doc) && resolvedDataDoc && resolvedDataDoc !== templateLayoutDoc)) {
+            return templateLayoutDoc;
+        }
+        // if we have a data doc that doesn't match the layout, then we're rendering a template.
+        // ... which means we change the layout to be an expanded view of the template layout.  
+        // This allows the view override the template's properties and be referenceable as its own document.
+
+        let expandedTemplateLayout = templateLayoutDoc["_expanded_" + dataDoc[Id]];
+        if (expandedTemplateLayout instanceof Doc) {
+            return expandedTemplateLayout;
+        }
+        if (expandedTemplateLayout === undefined)
+            setTimeout(() => {
+                templateLayoutDoc["_expanded_" + dataDoc[Id]] = Doc.MakeDelegate(templateLayoutDoc);
+                (templateLayoutDoc["_expanded_" + dataDoc[Id]] as Doc).title = templateLayoutDoc.title + " applied to " + dataDoc.title;
+            }, 0);
+        return templateLayoutDoc;
+    }
+
     export function MakeCopy(doc: Doc, copyProto: boolean = false): Doc {
         const copy = new Doc;
         Object.keys(doc).forEach(key => {