ReactJS-.map函数内的REST API查询？

Question

How do I generate repetitive mark-up elements in a React component, that also require a REST API query for each of them? Initially I had the calls completing in a for-each loop within the componentDidMount function. But that required calling setState inside the loop, in order to trigger a re-Render. The behavior was unstable, and apparently that technique is not a good idea.

So, now I'm trying to get the queries to run inside the .map function of my render (see below). But that's producing this error .

Is there a way to return the element value instead of a promise? (Probably more of a JS question than a React one...)
Or am I going about this the wrong way altogether?

return (<div>   
    {this.props.currentProject.Tasks.map((task => {
        return ProjectsService.getTaskBaselines(this.props.currentProject.PWAGuid, task.TaskId, this.props.context).then((baseline: any): any => {
            return (<div>{task.TaskName}</div>);
        })                                
    }))}
</div>);

Answer 1

It seems like you want to query all APIs and then handle the response once all are settled.

Try this:

const promises = this.props.currentProject.Tasks.map((task => {
        return new Promise(function(resolve, reject) {
              resolve(task);
        });

Promise.all(promises).then((data) => {
     this.setState({
          // act on all of your data
      });
});

Then render this.state in your render() function.