silverstripe-framework/docs/en/04_Changelogs/4.3.0.md

# 4.3.0

## Overview {#overview}

 - `DataList::column()` now returns all values and not just "distinct" values from a column as per the API docs
 - `DataList`, `ArrayList` and `UnsavedRalationList` all have `columnUnique()` method for fetching distinct column values
 - Take care with `stageChildren()` overrides. `Hierarchy::numChildren() ` results will only make use of `stageChildren()` customisations that are applied to the base class and don't include record-specific behaviour.
 - New React-based search UI for the CMS, Asset-Admin, GridFields and ModelAdmins.
 - A new `GridFieldLazyLoader` component can be added to `GridField`. This will delay the fetching of data until the user access the container Tab of the GridField.
 - `SilverStripe\VersionedAdmin\Controllers\CMSPageHistoryViewerController` is now the default CMS history controller and `SilverStripe\CMS\Controllers\CMSPageHistoryController` has been deprecated.

## Upgrading {#upgrading}

### Fetching distinct column values on DataList

Prior to this release `DataList` would erroneously return a distinct list of values from a column on an object.
If this behaviour is still required, please use `columnUnique()` instead.

### Using legacy GridField search API

GridFields now default to using the new search UI which uses [SilverStripe's FormSchema API](api:SilverStripe\Forms\Schema\FormSchema).

If you would rather continue using the old search API, you can remove the default `GridFieldFilterHeader` from your GridField configuration and replace with one whose _legacy_ flag has been enabled. 

To enable the legacy search API on a `GridFieldFilterHeader`, you can either:
* set the `useLegacyFilterHeader` property to `true`,
* or pass `true` to the first argument of its constructor.

To force the legacy search API on all instances of `GridFieldFilterHeader`, you can set it in your [configuration file](../../configuration):
```yml
SilverStripe\Forms\GridField\GridFieldFilterHeader:
  force_legacy: true
```

```php
public function getCMSFields()
{
    $fields = parent::getCMSFields();

    // Configure grid field to use legacy search API
    $config = new GridFieldConfig_RecordEditor();
    $config->getComponentsByType(GridFieldFilterHeader::class)->useLegacyFilterHeader = true;
    
    $grid = GridField::create('Companies', 'Companies', DataList::create(Company::class), $config);
    $fields->addFieldToTab('Root.Company', $grid);
    
    return $fields;
}

```

### Keep using the legacy `CMSPageHistoryController`

To keep using the old CMS history controller for every page type, add the following entry to your YML config.

```yml
SilverStripe\Core\Injector\Injector:
  SilverStripe\CMS\Controllers\CMSPageHistoryController:
    class: SilverStripe\CMS\Controllers\CMSPageHistoryController
```

If you want to use both CMS history controllers in different contexts, you can implement your own _Factory_ class.
```yml
SilverStripe\Core\Injector\Injector:
  SilverStripe\CMS\Controllers\CMSPageHistoryController:
    factory:
      App\MySite\MyCustomControllerFactory
```

[Implementing a _Factory_ with the Injector](/developer_guides/extending/injector/#factories).

### Using the history viewer for custom DataObjects

For information on how to implement the history viewer UI in your own versioned DataObjects, please refer to
[the Versioning documentation](../developer_guides/model/versioning).