View inheritance and XPath in practice

Extending views safely: inherit_id, positions, attribute changes, priority, mode='primary' and debugging inheritance.

In this lesson

Positions and the field shortcut
Primary mode, priority and group-restricted extensions
Debugging inheritance errors

Key points

inherit_id + xpath/field with inside, after, before, replace, attributes, move
attributes: set, add, remove values
mode='primary' makes a variant; priority orders extensions
'cannot be located in parent view' = XPath didn't match on this version

Real-world example

After upgrading 18→19, a client's invoice form extension failed to apply: the target group had been renamed in the core view. The consultant opened Edit View on 19, found the new name attribute, updated the XPath, and added a test that installs the module to catch it next year.

Questions and answers

What does <attribute name="class" add="text-danger" separator=" "/> do?

Adds a class to the existing class list.

Where do you see all inherited views of a form?

Developer mode → Edit View: Form → Inherited views tab.

Read the full lesson, worked example and quiz