I'm extending a Magento 2 module which doesn't use UI. I've added a new column for a custom attribute to the module's Admin grid. However, I'm trying to change the attribute to a multiselect, and I can't find a way to support multiselect without UI.
Here is what I have now:
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<body>
<referenceBlock name="adminhtml.locator.grid.columnSet">
<block class="Magento\Backend\Block\Widget\Grid\Column" as="brand" before="status">
<arguments>
<argument name="header" xsi:type="string" translate="true">Brand</argument>
<argument name="index" xsi:type="string">brand</argument>
<argument name="header_css_class" xsi:type="string">col-brand</argument>
<argument name="column_css_class" xsi:type="string">col-brand</argument>
<argument name="type" xsi:type="string">options</argument>
<argument name="options" xsi:type="options" model="Mycompany\StoreLocator\Source\Brand\Options"/>
</arguments>
</block>
</referenceBlock>
</body>
</page>
This works great so long as I don't use a select attribute, but it breaks with a multiselect attribute. Filtering is also broken for this attribute once it has a comma in the attribute value.
Is there any way to support this without converting the whole form to UI?