为什么firestoreConnect不读取'props.match.params.id' - 'where'使用react.js和redux的集合查询？

Question

I am trying to filter products by category id using react, redux and firestore. I am using firestoreConnect to query the products collection by the selected category id in a Link to statement - props.match.params.id and storing that query as filteredProducts.

This param id is not empty when console.log inside the render and firestoreConnect but in the where clause - it is not defined or null. Consequently, the query collection is empty and thus not retrieving any records.

Any solution will be appreciated.

I could output the props.match.params.id inside the firestoreConnect. Also, I have tried to index the firetore collection on firebase website without success.

Here is what I have in the products listing.js:

import React, { Component } from "react";
import { compose } from "redux";
import { connect } from "react-redux";
import { firestoreConnect } from "react-redux-firebase";

class Listing extends Component {
  render() {
    console.log(this.props.match.params.id); // able to log
    const { filteredProducts } = this.props;
    return (
      <div>
        {filteredProducts && filteredProducts.length > 0 ? (
        <ul>
           {filteredProducts.map(product => (
              <li>{product.name}</li>
            ))}
        </ul>
      ) : (
         <div>no products matching criteria </div>
       )}
      </div>
   );
 }
}

const mapStateToProps = ({ firestore: { ordered } }) => ({
  filteredProducts: ordered.filteredProducts
});

export default compose(
  connect(mapStateToProps),
  firestoreConnect(props => [
    {
      collection: "products",
      where: ["category", "==", props.match.params.id], 
      storeAs: "filteredProducts"
    }
  ])
)(Listing);`

and here is the list of dependencies in the package.json file

"firebase": "^5.11.1",
"react": "^16.6.3",
"react-dom": "^16.6.3",
"react-redux": "^5.1.1",
"react-redux-firebase": "^2.2.6",
"react-reveal": "^1.2.2",
"react-router-dom": "^5.0.0",
"react-scripts": "2.1.1",
"redux": "^4.0.1",
"redux-firestore": "^0.6.4",
"redux-thunk": "^2.3.0"

What I am trying to achieve is a filtered collection of products by a category id

what I am getting is null or undefined array object

Answer 1

As you are using the latest version of React Router (v4+), you have to wrap the whole component with the " withRouter " higher-order component. It will pass updated match, location, and history props to the wrapped component whenever it renders.

At first, you have to import the withRouter.

import { withRouter } from "react-router";

Then you have to wrap it with withRouter.

export default withRouter(compose(
    connect(mapStateToProps),
    firestoreConnect(props => [
      {
        collection: "products",
        where: ["category", "==", props.match.params.id], 
        storeAs: "filteredProducts"
      }
    ])
  )(Listing));

Hope this helps.