未在render（）中呈现的React元素数组

Question

I am learning react through creating some sample projects using Meteor. I think I am getting a grasp of it but now I am stuck again.

I am using a twitter API to fetch the most recent 3 tweets from the BOINGBOING twitter page. I can confirm that I have the API working and can console out an array of objects containing created_at , text , & value.entities.media[0].media_url which is basically the image url of a tweet.

What I am trying to achieve is to display the three tweets within a div tag containing an img & 2 p tags.

I am forming the DOM with JSX, pushing the DOM for current tweet into an array and then passing this array to render(). I thinking an array of React elements should render right? So what is my mistake, I am seeing nothing?

getTweets: function(){

    Meteor.call('fetchTweets', function(error, result){
        var res = [];

        // cycle through the results and build reat elements
        _.each(result, function(value, key, list){
            var {created_at, text, ...other} = value;

            if (value.entities.media != undefined) {
                // no image
                let node = (
                    <div>
                        <p>{created_at}</p>
                        <p>{text}</p>
                    </div>                        
                    );
                console.log(node);
                res.push(node);

            } else {
                // has image
                let node = (
                    <div>
                        <img src={value.entities.media[0].media_url} alt=""/>
                        <p>{created_at}</p>
                        <p>{text}</p>
                    </div>                        
                );
                res.push(node);

            }
        })
        console.log(res);
        return res;          

    });        
},

render: function() {

    return (
        <div>
            <div className="alltweets">{this.getTweets()}</div>
        </div>          
    );
}

When I console out my react elements, this is what I see.

Answer 1

I don't know meteor, but it looks like Meteor.call is asynchronous, so it can't just return res . You'd probably need to call setState({ someKey: res }) in your asyncCallback , and use that state in your render() call.

Answer 2

I'm not sure you're using react correctly in this situation, here's how I'd do it.

const TweetList = React.createClass({


    getInitialState() {
        const tweets = Meteor.call('fetchTweets', function(error, result){ 
            return result;
        }
        return { 
            tweets: tweets
        }
    },

    render() {
        const {tweets} = this.state;
        {data.map(this._renderTweets)}
    },

    _renderTweets(tweet, ii) {
        if (!tweet.entities.media) {
            return(
                <div key={ii}>
                    <p>{tweet.created_at}</p>
                    <p>{tweet.text}</p>
                </div> 
            );
        }
        else {
            return(
                <div key={ii}>
                    <img src={tweet.entities.media.media_url} alt=""/>
                    <p>{tweet.created_at}</p>
                    <p>{tweet.text}</p>
                </div> 
            );
        }
    }
});

And then you would render that to the DOM.