how to get data from graphql server using react and react-apollo?

Question

After about 6-8 hours trying, I'm resorting to help. All I want is to query my graphql server and the response data to be entered into my react component as props (See ParameterBox.js). Please let me know what I'm doing wrong.

For Reference: INDEX.JS FILE (Likely correct)

import React from 'react';
import ReactDOM from 'react-dom';
import {
    ApolloClient,
    createNetworkInterface,
    ApolloProvider,
} from 'react-apollo';
import App from './App';


const networkInterface = createNetworkInterface({
    uri: 'http://localhost:3001/graphql'
});
const client = new ApolloClient({
    networkInterface: networkInterface
});

ReactDOM.render(
    <ApolloProvider client={client}>
        <App />
    </ApolloProvider>,
    document.getElementById('root')
);

For Reference: APP.JS FILE (I think it's correct)

//App.js
import React, { Component } from 'react';
import ParameterBox from './ParameterBox';

class App extends Component {
    render(){
        return(
            <div>
                <ParameterBox />
            </div>
        )
    }
}
export default App;

PARAMETERBOX.JS FILE (Here is where the issue is, somewhere...)

//ParameterBox.js
import React, { Component } from 'react';
import axios from 'axios';
import { gql, graphql } from 'react-apollo';
import ParameterList from './ParameterList';

class ParameterBox extends Component {
    constructor (props) {
        super(props);
        this.state = { data: [] };
        this.loadParamsFromServer = this.loadParamsFromServer.bind(this);
    }
    //*** Old Method ***/
    // I still set my data using the old methods of API urls. I want to switch to GraphQL
    loadParamsFromServer(){
        axios.get('http://localhost:3001/api/params')
            .then (res => {
                this.setState({ data: res.data });
            })
    }
    //**** end old method ****/
    componentDidMount() {
        this.loadParamsFromServer();
    }
    render(){
        return(
            <div >
                <h2> Parameters: </h2>
                <p> HOW DO I GET IT HERE? {this.props.AllParamsQuery } </p>
                <ParameterList
                    data={ this.state.data }/>
            </div>
        )
    }
}

const AllParams = gql`
    query AllParamsQuery {
        params {
            id,
            param,
            input
        }
    }`;

export default graphql(AllParams, {name: 'AllParamsQuery'})(ParameterBox);

Answer 1

You may find it helpful to review the Apollo documentation for basic queries here.

When you wrap your component with the graphql HOC, it will send your query to the server and then make the result available to your component as this.props.data. So, the result for your particular query would be found at this.props.data.params (the operation name, AllParamsQuery is not referenced inside the returned data).

The other thing to bear in mind is that the GraphQL is asynchronous, so while props.data will always be available, initially it will be empty. Your render logic will need to account for that fact by verifying that this.props.data.params is truthy before tyring to render it. You can also check whether the query is still in flight or has completed.

Edit: because you define a name property (AllParamsQuery) inside the config object you pass to graphql(), your query results will be available as that prop instead of data -- i.e. 'this.props.AllParamsQuery.params`.