Schema

Formie uses PHP-defined schema to render many parts of the form builder, including field settings, notification settings, page button settings and integration form settings. A schema is an array of nodes that describe the UI the builder should render and the settings those inputs should save.

Most schemas are built with SchemaHelper methods. You can also write raw schema nodes when you need a field or layout the helper does not cover.

use Craft;
use verbb\formie\helpers\SchemaHelper;

return [
    SchemaHelper::textField([
        'label' => Craft::t('formie', 'Placeholder'),
        'instructions' => Craft::t('formie', 'The text that will be shown if the field doesn’t have a value.'),
        'name' => 'placeholder',
    ]),
    SchemaHelper::lightswitchField([
        'label' => Craft::t('formie', 'Required Field'),
        'instructions' => Craft::t('formie', 'Whether this field should be required when filling out the form.'),
        'name' => 'required',
    ]),
];

Schema Nodes

A field node uses $field to choose the input type, and name to choose the setting key that will be saved. Common attributes include label, instructions, required, validation, options, placeholder and if.

[
    '$field' => 'select',
    'label' => Craft::t('formie', 'Display Type'),
    'instructions' => Craft::t('formie', 'Choose how the field should be displayed.'),
    'name' => 'displayType',
    'options' => [
        ['label' => Craft::t('formie', 'Dropdown'), 'value' => 'dropdown'],
        ['label' => Craft::t('formie', 'Radio Buttons'), 'value' => 'radio'],
    ],
]

The schema is rendered by the form builder UI, so these nodes are not Twig templates. Treat the array as the source of truth for the editor experience.

Helpers

SchemaHelper keeps common nodes shorter and gives Formie a single place to apply its own defaults. Prefer helpers for common field types and reusable Formie settings.

Reusable Formie field-setting helpers include:

Layout and HTML

Use $el for plain HTML elements and children to nest schema nodes. This is helpful when you need grouping, extra explanatory content or a small layout wrapper around multiple inputs.

[
    '$el' => 'div',
    'attrs' => [
        'class' => 'some-wrapper',
    ],
    'children' => [
        [
            '$el' => 'p',
            'children' => Craft::t('formie', 'These settings control how the value is limited.'),
        ],
        SchemaHelper::numberField([
            'label' => Craft::t('formie', 'Maximum'),
            'name' => 'max',
        ]),
    ],
]

Use $cmp when you need to render a registered form-builder component rather than a plain HTML element. Formie registers several builder-specific components and fields on top of the shared SchemaForm system, including field builders, notification editors, integration settings, preview components and Formie-specific field inputs.

Conditions

Use if to show a schema node only when a condition is met. The simplest form checks another value in the same schema scope.

SchemaHelper::textField([
    'label' => Craft::t('formie', 'Error Message'),
    'instructions' => Craft::t('formie', 'When validating the form, show this message if an error occurs. Leave empty to retain the default message.'),
    'name' => 'errorMessage',
    'if' => 'required',
])

For nested schemas, Formie tracks child prefixes so validation and error state still resolve against the correct setting path. Helpers like tableField(), groupField() and Formie’s nested layout fields handle the common cases for you.

Tables

Tables are useful for settings with multiple rows, such as dropdown options or table columns.

SchemaHelper::tableField([
    'label' => Craft::t('formie', 'Options'),
    'instructions' => Craft::t('formie', 'Define the available options for users to select from.'),
    'name' => 'options',
    'enableBulkOptions' => true,
    'newRowDefaults' => [
        'default' => false,
    ],
    'columns' => [
        [
            'type' => 'text',
            'name' => 'label',
            'label' => Craft::t('formie', 'Option Label'),
            'required' => true,
        ],
        [
            'type' => 'value',
            'name' => 'value',
            'label' => Craft::t('formie', 'Value'),
            'source' => 'label',
        ],
        [
            'type' => 'radio',
            'name' => 'default',
            'label' => Craft::t('formie', 'Default'),
            'allowUnselect' => true,
        ],
    ],
])

Common table column types include text, value, handle, checkbox, radio and select.

Preview Schema

Field previews use a smaller preview schema rendered by the form builder preview layer. Use defineFormBuilderPreviewSchema() on a field and return preview helpers where possible.

public function defineFormBuilderPreviewSchema(): array
{
    return [
        SchemaHelper::previewInput(),
    ];
}

Preview helpers include previewInput(), previewTextarea(), previewSelect(), previewChoiceList(), previewContainerParent(), previewElementField(), previewPhone(), previewPayment(), previewTable(), previewMessage(), previewRichText(), previewHtml(), previewHeading(), previewGroup(), previewSection(), previewSignature(), previewSummary(), previewAgree() and previewRecipients().

Define field previews with preview schema so the builder can render their structure.