extra_views/views/webclient_templates.xml
<?xml version="1.0"?>
<odoo>
<template id="assets_backend" name="extra_views" inherit_id="web.assets_backend">
<xpath expr="." position="inside">
<script type="text/javascript" src="/extra_views/static/src/lib/echarts.min.js"></script><!-- 第三方js库-->
<script type="text/javascript" src="/extra_views/static/src/js/extra_widget.js"></script>
<script type="text/javascript" src="/extra_views/static/src/js/extra_views.js"></script>
<link rel="stylesheet" type="text/less" href="/extra_views/static/src/less/extra_views.less"/>
</xpath>
</template>
</odoo>