fix: add hooks to call extra-data

Author: adyfk

src/v2/hooks/useExtra.ts

@@ -0,0 +1,32 @@
+import {
+  useContext,
+} from "react";
+import { IForm } from "../logic/createForm";
+import { FormContext } from "../contexts/FormContext";
+import useSubscribeAndCompare from "./useSubscribeAndCompare";
+
+export const useExtra = <T>(props: {
+  defaultValue?: any;
+  form?: any;
+  name: string;
+  // eslint-disable-next-line no-unused-vars
+  log?: () => void;
+}) => {
+  const { form: formContext } = useContext(FormContext);
+  const { form = formContext, name } = props as { form: IForm<any>, name: string };
+
+  useSubscribeAndCompare({
+    form,
+    subject: "extras",
+    getState() {
+      return form.getExtra(name);
+    },
+  });
+
+  return {
+    state: form.getExtra(name) as T,
+    form,
+  };
+};
+
+export default useExtra;

src/v2/logic/createForm.ts

@@ -51,6 +51,7 @@ export interface ISubject {
   fields: any[];
   containers: any[];
   supports: any[];
+  extras: any[];
 }
 
 export type IEventCallback = () => boolean
@@ -130,6 +131,7 @@ const createForm = <TSchema>(props: ICreateFormProps<TSchema>) => {
     fields: [],
     containers: [],
     supports: [],
+    extras: [],
   };
 
   const parse = (expression: IExpressionString, terms: Record<string, any> = {}, version: string = "v1") => {
@@ -143,6 +145,11 @@ const createForm = <TSchema>(props: ICreateFormProps<TSchema>) => {
     if (!key) return undefined;
     return get(_state.values, key);
   }
+  // extras
+  function getExtra(key?: string) {
+    if (!key) return undefined;
+    return get(_config.extraData, key);
+  }
   function initValue(key: string, value: any) { set(_state.values, key, value); }
   // fieldState
   function getError(key?: string) {
@@ -717,6 +724,7 @@ const createForm = <TSchema>(props: ICreateFormProps<TSchema>) => {
     setContainerFormState,
     setSupportFormState,
     getValue,
+    getExtra,
     setValue,
     getError,
     setError,