A missing custom excerpt panel does not prove that an excerpt was deleted. First compare the saved value with the control that displays it, then check whether the Gutenberg DataForm inspector experiment is enabled.
Keep the experiment separate from a final release
The WordPress testing call describes rebuilding the Post or Page settings sidebar on DataForm, with a related Quick Edit interface. It is available as an experiment in Gutenberg 24.0 or newer and was aimed at WordPress 7.2. The exact extension surface is still something to verify in the build you test. Do not assume a final removal or replacement API from a roadmap alone.
If your plugin extends the old excerpt panel, inventory that integration before switching the experiment on. Record whether it displays the normal excerpt, custom metadata or both. Those values may have different storage and permissions even if they appear in one panel.
Capture the value before testing the interface
Use a staging post with a distinctive synthetic excerpt such as "Inspector fixture: manual summary A". Save it and record the post ID. Keep an exported record or a read-only API response with sensitive fields removed. Do not use a customer post as a scratchpad.
Toggle the experiment only in the test environment. Compare the sidebar with it off and on while leaving the post type, user role and plugin set unchanged. A second simultaneous theme or plugin update makes the result harder to interpret.
Manual text: Original value preserved. Empty field: No unwanted write. Custom metadata: Separate values stay separate. Quick Edit: Same supported value persists. Explanatory checklist, not a customer test result.
Run a save-and-reopen matrix
| Case |
Check |
| Existing manual excerpt |
Value remains after opening the new inspector |
| Empty excerpt |
Merely opening the panel does not create text |
| Custom field beside excerpt |
Its value is not overwritten by the excerpt |
| Site Editor Quick Edit |
Same supported value appears and persists |
| Restricted editor role |
Existing access boundaries remain intact |
If the custom control is missing, do not immediately save an empty replacement field. First inspect whether the data still exists. If it does, the likely investigation is registration, rendering or extension compatibility. If it does not, compare the outgoing save payload and server response to identify the write that changed it.
Choose the right fix
A site owner should report the exact experiment state and plugin version to the plugin maintainer, with a synthetic reproduction. A developer should follow the current supported fields and view configuration for the target build and test both editor and Quick Edit. Avoid implementing a speculative replacement API based only on an example from an older proposal.
For a saved excerpt that exists but does not appear in an archive, see why WordPress post excerpts do not update. Template output and editor-panel registration are different problems and should not be merged into one diagnosis.
Acceptance criteria
The same intended value must survive editing from each supported interface, saving, reopening and changing role. Verify the public template separately. Keep the original fixture and configuration so a rollback restores the interface without discarding editorial data. Do not disable access checks merely to make a control visible.
Get help with a WordPress editor compatibility issue and include a before/after value comparison.
Source: DataForm editor inspector testing call. This is a suggested regression procedure; it does not assert that any particular plugin has failed it.
References reviewed October 17, 2026. Examples are explanatory, not customer test results.
For generated block controls rather than a post sidebar panel, use the separate attribute-schema diagnostic in PHP-Only WordPress Block Allows Wrong Values? Check Array Enums.
If the inspector appears but grouped fields validate or summarize differently, review the layout-to-data mapping: WordPress DataForm Group Validation or Summary Changed?.