404 error when rendering component from state in react-redux app with react-routerv4?

Question

*This is a React-Redux tutorial, so please no other solutions :)

Desired behavior: Pass props of parent component to the PostDetail component from state controlled by redux

Current output:

(1) 204 Result:

http://localhost:3001/react/8xf0y6ziyjabvozdd253nd
Request Method: OPTIONS
**strong text**Status Code: 204 No Content

(2) Consoled Errors:

GET http://localhost:3001/react/8xf0y6ziyjabvozdd253nd 404 (Not Found)
    :3000/react/8xf0y6ziyjabvozdd253nd:1 

Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

Inside my app (root.js) file I have the PostDetail component I want to route to like this:

    import React, { Component } from 'react';
    import { Route } from 'react-router-dom'
    import Categories from './Categories'
    import ListPosts from './ListPosts'
    import Header from './Header'
    import PostDetail from './PostDetail'

    class App extends Component {
      render() {
        return (
          <div>
            <Header />
            <Categories />
            <ListPosts />
            <Route exact path="/:category/:id" component={PostDetail}/>
         </div>

Then in the PostDetail nested component (inside the ListPosts component) I have a function inside a material-ui flatbutton, (important sidenote: The PostDetail component does have a console.log statement that is being called, but the props.post is undefined):

    selectPost = (selectedCategory, selectedPost) => {
      console.log('selectedCategory', selectedCategory, selectedPost)
      this.props.getSpecificPost(selectedCategory, selectedPost);
    }
   return (
    <CardActions>
        <FlatButton
          label="See Thread"
          // href={`/${post.category}/${post.id}`}
          containerElement={<Link to={`/${post.category}/${post.id}`} post={this.props.post} />}
          onClick={() => this.selectPost(post.category, post.id)}
        />
      )

In this same component are my mapStateToProps and mapDispatchToProps:

   const mapStateToProps = state => ({
     posts: state.postsReducer.posts,
     loading: state.postsReducer.loading,
     error: state.postsReducer.error,
     selectedCategory: state.categoriesReducer.selectedCategory,
     selectedPost: state.postsReducer.selectedPost,
   });

  function mapDispatchToProps (dispatch) {
    return {
     getSpecificPost: (selectedCategory, selectedPost) => 
         dispatch(getSpecificPost(selectedCategory, selectedPost)),
     fetchPosts: (selectedCategory) => dispatch(fetchPosts(selectedCategory))
    }
   }

 export default withRouter(connect(
   mapStateToProps,
   mapDispatchToProps
  )(PostPreview))

I am using a redux-thunk action call that is calling to my api:

   export function getSpecificPost(selectedCategory, selectedPost) {
     console.log('getSpecificPost', selectedPost)
     return dispatch => {
      dispatch(beginFetchPosts());
      return fetch(selectedPost ? `${api}/${selectedCategory}/${selectedPost}` 
          : null, { headers })
      .then(
       res => res.json(),
       error => console.log('An error occured at  getSpecificPost', error)
       )
       .then(json => {
         dispatch(selectPostSuccess(json));
         return json
         })
        }
       }

And a reducer:

    const initialState = {
     posts: [],
     categories: [],
     loading: false,
     error: null,
     selectedCategory: 'all',
     selectedPost: [],
     };

   export function postsReducer(state = readableInitialState, action) {
      switch(action.type) {
        case C.SELECTED_POST:
          return {
          ...state,
          loading: false,
          selectedPost: action.payload.selectedPost
         };

...And yes I finish the switch statement with a default statement and no syntax issues as far as a I know)

Answer 1

Whenever I see the error

Uncaught (in promise) SyntaxError: Unexpected token < in JSON at position 0

I get flashbacks to CORS issues that I had to tough out when setting up a project the first time and hitting a remote server for dev.

Could you provide your network response when going to this page from chrome dev tools? There should be no < at the start of a JSON so I'm thinking you don't have a react router issue but some sort of server config issue.

Answer 2

The problem is that you did not mention the method, whether it is GET, PUT and that is why the server is considering OPTIONS. You can use fetch call in a different way.

export function getSpecificPost(selectedCategory, selectedPost){
  return (dispatch) => {
    const baseURL = selectedPost ? `${api}/${selectedCategory}/${selectedPost}` : null 
    fetch(baseURL, {
      method: 'GET',
      headers: {
        'content-type': 'application/json'
      },
      body: JSON.stringify(`${headers}`)
    })
    .then(json => {
      dispatch(selectPostSuccess(json))
    })
  } 
}

You can also send data to the reducer instead of json by following code snippet.

export function getSpecificPost(selectedCategory, selectedPost){
  return (dispatch) => {
    const baseURL = selectedPost ? `${api}/${selectedCategory}/${selectedPost}` : null 
    fetch(baseURL, {
      method: 'GET',
      headers: {
        'content-type': 'application/json'
      },
      body: JSON.stringify(`${headers}`)
    })
    .then(json => response.json())
    .then(data => {
      dispatch(selectPostSuccess(data))
    })
  } 
}

I hope this could help you.