Feature Request: Support dynamic condition render for FormItem

[EscapeB]

• I have searched the issues of this repository and believe that this is not a duplicate.

What problem does this feature solve?

Sample: https://codesandbox.io/s/antd-reproduction-template-eky0k
Click Change form data -> Click rerun setFieldsValue

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Now, when we use dynamic rendering for FormItem like this:

{formValue.type === 1 && (
         <Form.Item> {getFieldDecorator ("input", {}) (<Input />)} </ Form.Item>
       )}

If you call setFieldsValue, there is a warning because the dynamic rendering field is not registered in the FieldsStore of rc-form: Warning: You cannot set a form field before rendering a field associated with the value.
You have to call setFieldsValue or setFieldsValue again to set the value of the dynamically rendered FormItem.

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现在在动态渲染FormItem的时候，例如

{formValue.type === 1 && (
        <Form.Item>{getFieldDecorator("input", {})(<Input />)}</Form.Item>
      )}

如果调用setFieldsValue，由于动态渲染field没有注册到rc-form的FieldsStore中，所以会有一个警告：Warning: You cannot set a form field before rendering a field associated with the value.
必须再次调用setFieldsValue或setFieldsValue才能设置动态渲染出来的FormItem的值。

What does the proposed API look like?

Can you support adding a props to FormItem: condition (may not call this name)
API example

  <Form.Item condition = {formValue.type === 1}> {getFieldDecorator ("input", {}) (<Input />)} </ Form.Item>

Register all dynamic FormItem in FieldsStore.
Notice that there is a hidden option in getFieldProps of rc-form
Is it possible to hide the item via css and set hidden option?

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能否支持在FormItem 中添加一个props： condition（可能不叫这个名字）
API例如

 <Form.Item condition={formValue.type === 1 }>{getFieldDecorator("input", {})(<Input />)}</Form.Item>

将所有动态的表单项都注册。
注意到rc-form的getFieldProps options参数中有hidden这一个选项。
是否能通过css和 rc-form getFieldProps options中的 hidden来隐藏和忽略该项？

[yoyo837]

我认为应该用不到你说的这个功能。
清楚当前哪些表单项生效是理所应当的。

sometingTrue && <Form.Item />

[EscapeB]

清楚当前哪些表单项生效是理所应当的。

知道哪些表单生效是当然的。
核心问题是当存在动态渲染表单项时，目前的机制setFieldsValue需要重复触发来回填表单项，例子里有说。
希望可以支持一次setFieldsValue即可回填。

[zombieJ]

Close since it's no more a problem in v4.