ReferenceField 一直显示空值加载栏

ReferenceField keeps showing loading bar on null value

我有以下 List 组件,其中 customeridtechnicianidReferenceField。有时我有 technicianid 作为 null。所以 UI 一直显示加载栏(如下图所示)。

问题: 我怎样才能告诉 ReferenceField 处理 null 并只显示空字符串。

export const AppointmentList = (props) => (
    <List title="All Appointments" {...props}>
        <Datagrid>
            <ReferenceField source="customerid" reference="customers" label="Customer" >
                <TextField source="name" />
            </ReferenceField>
            <TextField source="name" label="Name" />
            <DateField source="scheduleddt" label="Schedule Date" />
            <ReferenceField source="technicianid" reference="technicians" label="Technician" >
                <TextField source="name" />
            </ReferenceField>
            <DateField source="createddatetime" label="Created" />
        </Datagrid>
    </List>
);

您需要 'allowEmpty' 属性。

export const AppointmentList = (props) => (
    <List title="All Appointments" {...props}>
        <Datagrid>
            <ReferenceField source="customerid" reference="customers" label="Customer" >
                <TextField source="name" />
            </ReferenceField>
            <TextField source="name" label="Name" />
            <DateField source="scheduleddt" label="Schedule Date" />
            <ReferenceField source="technicianid" reference="technicians" label="Technician" allowEmpty>
                <TextField source="name" />
            </ReferenceField>
            <DateField source="createddatetime" label="Created" />
        </Datagrid>
    </List>
);

https://marmelab.com/admin-on-rest/Inputs.html#referenceinput

我们目前正在努力:)