这是我的情况:
- 在this.handleFormSubmit()上,我正在执行this.setState()
- 在this.handleFormSubmit()内部,我正在调用this.findRoutes(); -这取决于this.setState()的成功完成
- this.setState(); 在this.findRoutes被调用之前没有完成...
- 在调用this.findRoutes()之前,如何等待this.handleFormSubmit()内部的this.setState()完成?
较差的解决方案:
- 将this.findRoutes()放入componentDidUpdate()
- 这是不可接受的,因为将有更多与findRoutes()函数无关的状态更改。我不希望在不相关的状态更新时触发findRoutes()函数。
请参见下面的代码段:
handleFormSubmit: function(input){
// Form Input
this.setState({
originId: input.originId,
destinationId: input.destinationId,
radius: input.radius,
search: input.search
})
this.findRoutes();
},
handleMapRender: function(map){
// Intialized Google Map
directionsDisplay = new google.maps.DirectionsRenderer();
directionsService = new google.maps.DirectionsService();
this.setState({map: map});
placesService = new google.maps.places.PlacesService(map);
directionsDisplay.setMap(map);
},
findRoutes: function(){
var me = this;
if (!this.state.originId || !this.state.destinationId) {
alert("findRoutes!");
return;
}
var p1 = new Promise(function(resolve, reject) {
directionsService.route({
origin: {'placeId': me.state.originId},
destination: {'placeId': me.state.destinationId},
travelMode: me.state.travelMode
}, function(response, status){
if (status === google.maps.DirectionsStatus.OK) {
// me.response = response;
directionsDisplay.setDirections(response);
resolve(response);
} else {
window.alert('Directions config failed due to ' + status);
}
});
});
return p1
},
render: function() {
return (
<div className="MapControl">
<h1>Search</h1>
<MapForm
onFormSubmit={this.handleFormSubmit}
map={this.state.map}/>
<GMap
setMapState={this.handleMapRender}
originId= {this.state.originId}
destinationId= {this.state.destinationId}
radius= {this.state.radius}
search= {this.state.search}/>
</div>
);
}
});