# Overriding settings via the XML layout

**Most settings of the LokiCheckout are configured in the Magento Admin Panel under Stores > Configuration > Loki > Loki Checkout. But sometimes you want a setting to be fixed by your theme or module, or you want a setting to differ per layout handle (for instance, per skin). For this, the core module `LokiCheckout_Core` allows you to override most of its settings via the XML layout.**

## The `loki-checkout.config` block
The layout handle `loki_checkout` (file `LokiCheckout_Core::layout/loki_checkout.xml`) defines a non-rendering block `loki-checkout.config` with an empty array argument `config`:

```xml
<block name="loki-checkout.config" class="Magento\Framework\View\Element\Text">
    <arguments>
        <argument name="config" xsi:type="array"/>
    </arguments>
</block>
```

By adding items to this `config` argument, you can override settings. The name of each item is the configuration path; the value of each item is the value to use instead of the Store Configuration value.

## Example: Disabling the "same as billing" behaviour
For instance, to disable the setting **Field settings > Enable Same As Billing Checkbox** (`loki_checkout/fields/enable_same_as_billing`), add the following to a file `view/frontend/layout/loki_checkout.xml` in your own module or theme:

```xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:View/Layout:etc/page_configuration.xsd">
    <body>
        <referenceBlock name="loki-checkout.config">
            <arguments>
                <argument name="config" xsi:type="array">
                    <item name="loki_checkout/fields/enable_same_as_billing" xsi:type="boolean">false</item>
                </argument>
            </arguments>
        </referenceBlock>
    </body>
</page>
```

With this, `LokiCheckout\Core\Util\SameAddressService::isEnabled()` returns `false`, so the shipping address is no longer regarded (and copied) as billing address and the billing address form is used instead.

> The checkbox block `loki-checkout.billing.address.shipping-as-billing` is added with the XML attribute `ifconfig="loki_checkout/fields/enable_same_as_billing"`. Magento evaluates `ifconfig` against the Store Configuration, not against the `loki-checkout.config` block. If the Store Configuration value is still enabled, the checkbox is still rendered (but it no longer has any effect). To hide it as well, remove the block.

To also get rid of the checkbox itself, add the following to `view/frontend/layout/loki_checkout_block_billing_address.xml`:

```xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:View/Layout:etc/page_configuration.xsd">
    <body>
        <referenceBlock name="loki-checkout.billing.address.shipping-as-billing" remove="true"/>
    </body>
</page>
```

Note that the module `LokiCheckout_BillingFirst` adds a similar block `loki-checkout.shipping.address.billing-as-shipping` with the same `ifconfig` attribute, so when using that module, remove that block instead.

## Example: Multiple settings at once
Multiple items can be added at once. Use the right `xsi:type` for the value (`boolean`, `number`, `string`):

```xml
<referenceBlock name="loki-checkout.config">
    <arguments>
        <argument name="config" xsi:type="array">
            <item name="loki_checkout/fields/enable_same_as_billing" xsi:type="boolean">false</item>
            <item name="loki_checkout/fields/hide_region_when_optional" xsi:type="boolean">true</item>
            <item name="loki_checkout/cart/max_items_visible_count" xsi:type="number">5</item>
            <item name="loki_checkout/newsletter/default_value" xsi:type="boolean">false</item>
        </argument>
    </arguments>
</referenceBlock>
```

## Example: A setting per skin
Because this is regular XML layout, you can put the override in any layout handle that is loaded in the checkout. For instance, the core adds a handle `loki_checkout_skin_SKIN` for the current skin (like `loki_checkout_skin_default` and `loki_checkout_skin_onestep`). To select the first shipping method automatically only with the One Step skin, add a file `view/frontend/layout/loki_checkout_skin_onestep.xml`:

```xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:View/Layout:etc/page_configuration.xsd">
    <body>
        <referenceBlock name="loki-checkout.config">
            <arguments>
                <argument name="config" xsi:type="array">
                    <item name="loki_checkout/shipping/select_default_shipping_method" xsi:type="boolean">true</item>
                </argument>
            </arguments>
        </referenceBlock>
    </body>
</page>
```

## Which settings can be overridden?
Only settings that are read via the `getValue()` method of the class `LokiCheckout\Core\Config\Config` can be overridden. At this moment, these are:

| Configuration path | Admin label | `Config` method |
|---|---|---|
| `loki_checkout/fields/enable_same_as_billing` | Enable Same As Billing Checkbox | `enableSameAsBilling()` |
| `loki_checkout/fields/enable_vat_id_only_for_company` | Enable Vat ID Only For Companies | `enableVatIdOnlyForCompany()` |
| `loki_checkout/fields/hide_region_when_optional` | Hide Region When Optional | `hideRegionWhenOptional()` |
| `loki_checkout/fields/capitalize_country_in_preview` | Capitalize Country In Address Preview | `capitalizeCountryInPreview()` |
| `loki_checkout/shipping/select_default_shipping_method` | Select Default Shipping Method | `selectDefaultShippingMethod()` |
| `loki_checkout/billing/select_default_payment_method` | Select Default Payment Method | `selectDefaultPaymentMethod()` |
| `loki_checkout/newsletter/default_value` | Subscribe by default | `isNewsletterCheckedByDefault()` |
| `loki_checkout/cart/max_items_visible_count` | Maximum items visible | `getMaxCartItemsToShowByDefault()` |
| `loki_checkout/debug/enable` | Enable Debugging | `isDebug()` |
| `loki_checkout/debug/html_hints` | Add Hints to HTML Output | `addHtmlHints()` |
| `loki_checkout/debug/debug_block` | Add Debug Block | `addDebugBlock()` |
| `checkout/options/max_items_display_count` | (Magento core setting) | `getMaxCartItemsToDisplay()` |

The following settings can **not** be overridden this way, because they are read directly from the Store Configuration, and because they are needed before the layout is loaded:

- `loki_checkout/general/enable` (Enable)
- `loki_checkout/general/license_key` (License Key)
- `loki_checkout/general/theme` (Skin)
- `loki_checkout/general/grid_layout` (Address Grid Layout)

To use a different grid layout for a specific address form, use the block argument `grid_layout` instead (see [Changing the grid of field blocks](/checkout/dev/basic-customizations/changing-the-grid)).

## How it works
- The class `LokiCheckout\Core\Config\LayoutConfig` holds the overrides. Its constant `LayoutConfig::BLOCK_NAME` contains the block name `loki-checkout.config`.
- The observer `LokiCheckout\Core\Observer\LoadLayoutConfig` listens to the event `layout_generate_blocks_after` (in `etc/frontend/events.xml`) and calls `LayoutConfig::loadFromLayout()`, which reads the `config` argument of the block.
- `LokiCheckout\Core\Config\Config::getValue()` first checks `LayoutConfig::has($path)`. If the path is present, that value is returned. Otherwise, the Store Configuration value (store scope) is returned.

Some consequences of this:

- Overrides only apply once the layout has been generated. When no layout is generated (or the layout does not contain the block), the Store Configuration value is used.
- Code that reads the same path directly via `Magento\Framework\App\Config\ScopeConfigInterface` (including `ifconfig` attributes in the XML layout) does not see the override. In your own code, use the methods of `LokiCheckout\Core\Config\Config` instead to pick up overrides.
- Other LokiCheckout modules with their own configuration class are not affected by this block, unless they use `LokiCheckout\Core\Config\Config`.

> This feature was added to `LokiCheckout_Core` recently. If the class `LokiCheckoutCoreConfigLayoutConfig` does not exist in your installation, upgrade the module first.