问题
When first using Restangular on a working website I got the following JavaScript error:
Failed to instantiate module restangular due to: '_' is undefined
What am I missing? What does it mean that '_' is undefined (in the Restangular module)?
回答1:
It's a simple oversight. The '_' (underscore) is a JavaScript utility library that Restangular uses and depends on. Include Lodash or Undrescore library before the AngularJS library (in your HTML):
<script src="lodash.js"></script>
or
<script src="underscore.js"></script>
PS: Double check the library script and path exist as referenced in your SCRIPT tag.
Additional readings:
- Restangular Dependencies
- Why Does Restangular Depend on lodash / underscore
- Differences between lodash and underscore
来源：https://stackoverflow.com/questions/20408290/error-failed-to-instantiate-module-restangular-due-to-is-undefined