问题描述
如何使用 Redux Toolkit RTK Query 将查询参数传递给 api?
import { createApi,fetchBaseQuery } from '@reduxjs/toolkit/query/react';
const baseUrl = 'xxxxxxx';
export const postsApi = createApi({
reducerPath: 'posts',baseQuery: fetchBaseQuery({ baseUrl }),endpoints: (builder) => ({
getPostsByYear: builder.query({
query: (start,end) => { // Why is 'end' always undefined???
return {
url: 'posts/',params: { start,end },};
},}),getPosts: builder.query({
query: () => 'posts/',getPostByID: builder.query({
query: (name) => `posts/${name}`,});
export const { useGetPostsQuery,useGetPostsByYearQuery,useGetPostByIDQuery } = postsApi;
当尝试从组件传递参数时,似乎只能识别 start
值。 year
由 <PostOptions/>
组件中的 select 元素更新。它使用 useState
钩子。该值正确更新并调用了 useGetPostsByYearQuery
,但 end
参数始终未定义。所以,似乎我没有正确定义 api 端点。有什么建议吗?我想要它做的就是以 http://xxx/posts?start=start&end=end
的形式发送请求。
我什至尝试硬编码 end
参数的字符串值,例如useGetPostsByYearQuery(year,'2019')
,但在 api 回调中它仍然显示为 undefined
,所以我缺少一些更基本的东西。
const Post = () => {
const year = useSelector((state) => state.postOptions.year);
const yearPlusOne = parseInt(year,10) + 1;
const { data,error,isLoading } = useGetPostsByYearQuery(year,yearPlusOne);
return (
<SafeAreaView style={styles.container}>
<View style={styles.content}>
<Postheading />
<PostOptions></PostOptions>
</View>
</SafeAreaView>
);
};
export default Post;
解决方法
QueryArg
是泛型类型。
interface EndpointDefinitionWithQuery<
QueryArg,BaseQuery extends BaseQueryFn,ResultType
> {
query(arg: QueryArg): BaseQueryArg<BaseQuery>
}
来自文档 Defining Query Endpoints:
如果 query
回调需要额外的数据来生成 URL,则应将其编写为采用单个参数。如果您需要传入多个参数,请将它们格式化为单个“选项对象”。
因此您可以像这样为 QueryArg
方法声明泛型参数 builder.query
类型:
import { createApi,fetchBaseQuery } from '@reduxjs/toolkit/query/react';
const baseUrl = 'xxxxxxx';
export const postsApi = createApi({
reducerPath: 'posts',baseQuery: fetchBaseQuery({ baseUrl }),endpoints: (builder) => ({
getPostsByYear: builder.query<any,{ start: string; end: string }>({
query: (arg) => {
const { start,end } = arg;
console.log('arg: ',arg);
return {
url: 'posts/',params: { start,end },};
},}),});
export const { useGetPostsByYearQuery } = postsApi;
并像这样传递查询参数:
import React from 'react';
import { useGetPostsByYearQuery } from './hooks';
export default function App() {
const { data,error,isLoading } = useGetPostsByYearQuery({ start: '2019',end: '2021' });
return <div>app</div>;
}
日志:
arg: { start: '2019',end: '2021' }
版本:"@reduxjs/toolkit": "^1.6.0"