I would like to overide the following admin template src/vendor/magento/module-sales/view/adminhtml/templates/order/view/history.phtml
This is what I made
module.xml
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Module/etc/module.xsd">
<module name="Cpy_Sales" setup_version="0.1.0">
<sequence>
<module name="Magento_Sales" />
</sequence>
</module>
</config>
Cpy/Sales/view/adminhtml/layout/sales_order_view.xml
Already have one extend there for the items, this one seems to be fine
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" layout="admin-2columns-left"
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="order_items">
<action method="setTemplate">
<argument name="template" xsi:type="string">Cpy_Sales::order/view/items.phtml</argument>
</action>
</referenceBlock>
<referenceBlock name='order_history'>
<arguments>
<argument name='template' xsi:type='string'>Cpy_Sales::order/view/history.phtml</argument>
</arguments>
</referenceBlock>
</body>
</page>
Then my custom template is in : src/app/code/Cpy/Sales/view/adminhtml/templates/order/view/history.phtml
This template is basically the same but add an automatic "checked" attribute to the input history[is_customer_notified]
so there is nothing very magical in there.