FormField marks the Title constructor argument as optional, and DatalessField does not override the __construct method. HeaderField on the other hand goes against the grain of FormFields as a whole and requires the Title field, seemingly for no good reason (at least, not that the commit message for a68ba38478 indicates) - this seems like an accidental ommision. This commit looks to reinstate the optionality of this constructor argument for consistency's sake.
Plus it broke a module I was investigating.
* FIX Add accessibility labels and titles to previous, next, and add new buttons in GridFields
* API Replace FormActions with anchors to enable panel-based loading in GridField navigation buttons
* FIX Previous and Next links are now correctly disabled when end of lists are reached
* Add English translations
* MINOR: Change “Choose Page” to “Search or choose Page”
Based on discussions with James Ford, it wasn’t clear that you could
search.
* Use new translation key
* API Update FieldList::replaceField API to match removeByName
This specifically adds the parameter that `removeByName` has but `replaceField` does not. This parameter is set to `true` by default rather than inheriting the same default as `removeByField`. This is because the existing funtionality of `replaceField` was the same as if this parameter was set to `true`. This should be updated in SS5 to match the `removeByField` API.
* Add dataFieldOnly to CompositeField
- Missing conditionals for optional constructor args
- Missing calls to FieldList::setForm()
- Missing guards around naive calls to Form::Fields()->foo()
* Use new plus icon and refactor
* MINOR: Add ability to customise the visibility of the `Previous`, `Next` and `Add` buttons at a `GridField` level
* - Merge `showPrevious` and `showNext` to `showPagination` for grid fields
- Update documentation
- Improve performance for next/previous buttons by not fetching all list records
- Refactoring
* Refactor to fail gracefully on GridFieldPaginator
* Fix merge
* MINOR: Add `Previous`, `Next` and `Create New` actions in edit form
If the form is opened via a grid field, the filters will be retained so the previous/next record opened will be correct
* MINOR: Add ability to customise the visibility of the `Previous`, `Next` and `Add` buttons at a `GridField` level
* Fix invalid action when pressing the `New` button in an edit form unless `betterbuttons` module was installed
* - Merge `showPrevious` and `showNext` to `showPagination` for grid fields
- Update documentation
- Improve performance for next/previous buttons by not fetching all list records
- Refactoring
* Refactor to fail gracefully on GridFieldPaginator
