Type-safe transforms

const myForm = createForm({ age: '0' });

<Field
  of={myForm}
  path="age"
  transform={{ in: val => Number(val), out: val => val.toString() }}
>
  {(_, props) => <NumberInput {...props} />} // 'props.value' is typed as
  number
</Field>;

Versus @modular-forms/solid

• Field values can be objects or arrays.

  • This makes it possible to bind complex types like { minDate: Date; maxDate: Date }. The recommended way to do this in @modular-forms/solid is very verbose.

• Form values are non-nullable. This means never having to non-null assert.

• More flexible interface for interoping with custom form components.

  • Custom form components simply need to take in value, onBlur, and onChange.
  • Easily bind components that don't have an underlying input, textarea, or select element.

• Simpler handling of arrays.

  • There is no need to use FieldArray. This reduces JSX nesting.

export function MyForm() {
  const [fruitForm, { Form, Field, FieldArray }] = createForm({
    initialValues: {
      fruits: [
        {
          name: 'banana',
          isTasty: true,
        },
        {
          name: 'kiwi',
          isTasty: false,
        },
      ],
    },
  });

  return (
    <Form>
      <FieldArray name="fruits">
        {fieldArray => (
          <>
            <For each={fieldArray.items}>
              {(_, index) => (
                <Field name={`fruits.${index()}.isTasty`} type="boolean">
                  {(field, props) => (
                    <Checkbox {...props} value={field.value} />
                  )}
                </Field>
              )}
            </For>
          </>
        )}
      </FieldArray>
    </Form>
  );
}

vs. smorf:

Note that there's no need to pass the type prop, or separately pass the value prop.

export function MyForm() {
  const fruitForm = createForm({
    fruits: [
      {
        name: 'banana',
        isTasty: true,
      },
      {
        name: 'kiwi',
        isTasty: false,
      },
    ],
  });

  return (
    <form>
      <For each={fruitForm.value.fruits}>
        {(_, index) => (
          <Field of={fruitForm} path={`fruits.${index()}.isTasty`}>
            {(field, props) => <Checkbox {...props} />}
          </Field>
        )}
      </For>
    </form>
  );
}