[reactjs] Promise Error: Objects are not valid as a React child

I am trying to set the json to a state using user agent, I get the error:

Uncaught Invariant Violation: Objects are not valid as a React child (found: object with keys {...}). If you meant to render a collection of children, use an array instead or wrap the object using createFragment(object) from the React add-ons.

method to set state:
 getInitialState: function(){
    return {
        arrayFromJson: []
    }
},

loadAssessmentContacts: function() {
    var callback = function(data) {
        this.setState({arrayFromJson: data.schools})
    }.bind(this);

    service.getSchools(callback);
},

componentWillMount: function(){
    this.loadAssessmentContacts();
},

onTableUpdate: function(data){

    console.log(data);

},

render: function() {

    return (
        <span>{this.state.arrayFromJson}</span>
    );
}
service
getSchools : function (callback) {
        var url = 'file.json';
       request
            .get(url)
            .set('Accept', 'application/json')
            .end(function (err, res) {
                if (res && res.ok) {
                    var data = res.body;
                    callback(data);

                } else {
                    console.warn('Failed to load.');
                }
            });
    }
Json
{
"schools": [
{
  "id": 4281,
  "name": "t",
  "dfe": "t",
  "la": 227,
  "telephone": "t",
  "address": "t",
  "address2": "t",
  "address3": "t",
  "postCode": "t",
  "county": "t",
  "ofsted": "t",
  "students": 2,
  "activeStudents": 2,
  "inActiveStudents": 0,
  "lastUpdatedInDays": 0,
  "deInstalled": false,
  "inLa": false,
  "status": "unnassigned",
  "authCode": "t",
  "studentsActivity": 0
},......
]}

This question is related to reactjs superagent

The answer is


You can't do this: {this.state.arrayFromJson} As your error suggests what you are trying to do is not valid. You are trying to render the whole array as a React child. This is not valid. You should iterate through the array and render each element. I use .map to do that.

I am pasting a link from where you can learn how to render elements from an array with React.

http://jasonjl.me/blog/2015/04/18/rendering-list-of-elements-in-react-with-jsx/

Hope it helps!


You can't just return an array of objects because there's nothing telling React how to render that. You'll need to return an array of components or elements like:

render: function() {
  return (
    <span>
      // This will go through all the elements in arrayFromJson and
      // render each one as a <SomeComponent /> with data from the object
      {this.state.arrayFromJson.map(function(object) {
        return (
          <SomeComponent key={object.id} data={object} />
        );
      })}
    </span>
  );
}