From 77155458efcd9c6e20515a9305248cace3554084 Mon Sep 17 00:00:00 2001
From: "Kent C. Dodds" <kent+github@doddsfamily.us>
Date: Thu, 23 Apr 2015 12:18:51 -0600
Subject: [PATCH] docs(error/nonassign): add optional binding example

---
 docs/content/error/$compile/nonassign.ngdoc | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/docs/content/error/$compile/nonassign.ngdoc b/docs/content/error/$compile/nonassign.ngdoc
index 0762eea96c39..8a13fd8574bb 100644
--- a/docs/content/error/$compile/nonassign.ngdoc
+++ b/docs/content/error/$compile/nonassign.ngdoc
@@ -36,9 +36,25 @@ Following are invalid uses of this directive:
 ```
 
 
-To resolve this error, always use path expressions with scope properties that are two-way data-bound:
+To resolve this error, do one of the following options:
+
+- use path expressions with scope properties that are two-way data-bound like so:
+
 ```
 <my-directive bind="some.property">
 <my-directive bind="some[3]['property']">
 ```
 
+- Make the binding optional
+
+```
+myModule.directive('myDirective', function factory() {
+  return {
+    ...
+    scope: {
+      localValue: '=?bind' // <-- the '?' makes it optional
+    }
+    ...
+  }
+});
+```