Interface yii\base\Arrayable

Returns the list of additional fields that can be returned by toArray() in addition to those listed in fields().

This method is similar to fields() except that the list of fields declared by this method are not returned by default by toArray(). Only when a field in the list is explicitly requested, will it be included in the result of toArray().

参见：

• toArray()
• fields()

Returns the list of fields that should be returned by default by toArray() when no specific fields are specified.

A field is a named element in the returned array by toArray().

This method should return an array of field names or field definitions. If the former, the field name will be treated as an object property name whose value will be used as the field value. If the latter, the array key should be the field name while the array value should be the corresponding field definition which can be either an object property name or a PHP callable returning the corresponding field value. The signature of the callable should be:

function ($model, $field) {
    // return field value
}

For example, the following code declares four fields:

• email: the field name is the same as the property name email;
• firstName and lastName: the field names are firstName and lastName, and their values are obtained from the first_name and last_name properties;
• fullName: the field name is fullName. Its value is obtained by concatenating first_name and last_name.

return [
    'email',
    'firstName' => 'first_name',
    'lastName' => 'last_name',
    'fullName' => function ($model) {
        return $model->first_name . ' ' . $model->last_name;
    },
];

参见 toArray().

Converts the object into an array.