我的反应渲染中遇到持续的问题.
这段代码
/** @jsx React.DOM */
var AnswerRows = React.createClass({
componentDidMount: function() {
},render: function() {
{this.props.answers.map(function(answer,i) {
return (
<div id="answerRow">
<label className="AnswerText">
<input type="checkBox" value={answer.id} />
{answer.text}
</label>
</div>
);
},this)}
}
});
var QuizTaking = React.createClass({
componentDidMount: function() {
},render: function() {
return (
<div className="card-holder">
<div className="showQuestionCard x-card host">
<h3 dangerouslySetInnerHTML={{__html: this.props.question.text}}></h3>
<div className="answerRows">
<AnswerRows answers={this.props.question.answers}/>
</div>
<div className='submitAnswers'></div>
</div>
<div className="paper-shadow-bottom"></div>
</div>
)
}
})
会给我不变的违规：AnswerRows.render()：必须返回一个有效的ReactComponent.您可能已经返回undefined,数组或其他无效对象.错误.但是,这样做每次都有效：
/** @jsx React.DOM */
var TestIndex = React.createClass({
propTypes: {
},loadTest: function(i) {
window.location.replace(this.props.tests[i].url.replace(".json","/take"))
},render: function () {
return(
<div className="testTable card-holder">
<div className="card-contents">
{this.props.tests.map(function(test,i) {
return (
<div className="testTableRow x-card host" key={test.id}>
<label className="__TITLE">{test.title}
<button onClick={this.loadTest.bind(test,i)} key={i} type="button" className="StartButton paper-button raisedButton">Start this test</button>
</label>
<div className="paper-shadow-bottom"></div>
</div>
);
},this)}
</div>
</div>
)
}
});
我真的很想了解这里发生了什么,也许是“正确”的做法.
解决方法
您不能从render函数返回多个元素(如map函数返回的数组).另外,你缺少一个return语句.尝试这个：
var AnswerRows = React.createClass({
componentDidMount: function() {
},render: function() {
return (
<div>
{this.props.answers.map(function(answer,i) {
return (
<div id="answerRow">
<label className="AnswerText">
<input type="checkBox" value={answer.id} />
{answer.text}
</label>
</div>
);
},this)}
</div>
);
}
});
