React component run error.Uncaught Error: Minified React error #31

Question

I am trying to return some html label when write render in my component. Code like this:

 import React, {Component} from 'react';
import Request from 'react-http-request';


class NameForm extends React.Component {
constructor() {
    super();
    this.state = {value: '', result: ''};

    this.handleChange = this.handleChange.bind(this);
    this.handleSubmit = this.handleSubmit.bind(this);
}

handleChange(event) {
    this.setState({value: event.target.value});
}

handleSubmit(event) {
    var content = this.state.value;

    var split = content.split(/\s+/);

    var queryObject = new Object();

    queryObject.law = null;
    queryObject.character = null;
    queryObject.lawRule = null;
    if (split.length == 1) {
        queryObject.law = split[0];
    }
    else if (split.length == 2) {
        queryObject.law = split[0];
        queryObject.character = split[1];
    }
    else if (split.length > 2) {
        queryObject.law = split[0];
        queryObject.character = split[1];
        queryObject.lawRule = split[2];
    }
    // var json = JSON.stringify(queryObject);
    var json = "{\"law\":\"军工企业股份制改造实施暂行办法\",\"character\":\"第二章\"}";

    var test = JSON.stringify(<Fetchs args={json}/>);


    var request = new XMLHttpRequest();
    request.open('POST', 'http://localhost:8080/path', false);
    request.setRequestHeader('Content-Type', 'application/json');
    var resp = '';
    request.onreadystatechange = function (e) {
        if (this.status == 200) {
            resp = this.response;
        }
    }

    request.send(json);

    // console.info("XMLHttpRequest test is " + JSON.stringify(resp));

    // console.info("test is " + resp);

    this.setState({result: resp});

    event.preventDefault();
}


render() {

    // console.log("prite"+this.state.result.queryResults);
    // console.log("100"+this.strToJson(this.state.result));
    // console.log("200"+this.strToJson(this.state.result.queryResults));
    // alert(this.state.result);

    var parse = JSON.parse(this.state.result ? this.state.result : null);
    var out = parse ? parse.queryResults : null;
    for (var i = 0; out != null && i < out.length; i++) {
        if (out[i].keyword == null) {
            out[i].keyword = "{}";
            console.info("keyword is null");
        }
        else {
            // this.state.result.queryResults.keyword
            console.info("keword is not null");
            out[i].keyword = JSON.stringify(out[i].keyword);
        }
    }


    return (
        <div>
            <form onSubmit={this.handleSubmit}>
                <label>
                    Name:
                    <input type="text" value={this.state.value} onChange={this.handleChange}/>
                </label>
                <input type="submit" value="Submit"/>
            </form>
            <table border="10" >
                <tr>
                    <thead>
                    <th>GraphName</th>
                    <th>Relation</th>
                    <th>Content</th>
                    <th>KeyWord</th>
                    </thead>
                </tr>
                <tbody>

                {out}
                </tbody>
            </table>

        </div>
    );
 }
}


ReactDOM.render(<NameForm/>, document.getElementById('react'))

out is a array parsed from json data, like this:

My problem is that I want show out on page by table label, But use {out} I get a error, like this:

What troubled me is how to show out array in a table.

Answer 1

I believe your trouble maybe caused by the fact that you try to return array of objects in your react render method, instead try to map your objects and insert necessary fields in <p></p> tags. For example:

out.map(
  (object) => <p>object.content</p>
)

etc... Hope it helps!