等到条件成立为止？

问题描述

我在JavaScript中使用了 code> function。

现行代码：

  var current_latlng = null; 
函数gpsSuccess（pos）{
 //console.log('gpsSuccess'）; 
 if（pos.coords）{
 lat = pos.coords.latitude; 
 lng = pos.coords.longitude; 
} 
其他{
 lat = pos.latitude; 
 lng = pos.longitude; 
} 
 current_latlng = new google.maps.LatLng（lat，lng）; 
} 
 watchId = navigator.geolocation.watchPosition（gpsSuccess，
 gpsFail，{timeout：5000，maximumAge：300000}）; 
 $（'＃route-form'）。submit（function（event）{
 //用户提交表单，我们需要它们的位置... 
 while（current_location == null）{ 
 toastMessage（'Waiting for your location ...'）; 
 wait（500）; //我应该用什么来代替？
} 
 //继续找到找到的位置。 .. 
}）; 
  

解决方案

您可以使用超时尝试重新提交形式：

  $（'＃route-form'）。submit（function（event）{
 //用户提交表单，我们需要它们的位置... 
 if（current_location == null）{
 toastMessage（'Waiting for your location ...'）; 
 setTimeout（function（）{ $（'＃route-form'）。submit（）;}，500）; //尝试在超时后提交表单
返回false; 
} else {
 //继续定位找到... 
} 
}）; 
  

I'm using navigator.geolocation.watchPosition in JavaScript, and I want a way to deal with the possibility that the user might submit a form relying on location before watchPosition has found its location.

Ideally the user would see a 'Waiting for location' message periodically until the location was obtained, then the form would submit.

However, I'm not sure how to implement this in JavaScript given its lack of a wait function.

Current code:

var current_latlng = null;
function gpsSuccess(pos){
    //console.log('gpsSuccess');
    if (pos.coords) {
        lat = pos.coords.latitude;
        lng = pos.coords.longitude;
    }
    else {
        lat = pos.latitude;
        lng = pos.longitude;
    }
    current_latlng = new google.maps.LatLng(lat, lng);
}
watchId = navigator.geolocation.watchPosition(gpsSuccess,
                  gpsFail, {timeout:5000, maximumAge: 300000});
$('#route-form').submit(function(event) {
    // User submits form, we need their location...
    while(current_location==null) {
        toastMessage('Waiting for your location...');
        wait(500); // What should I use instead?
    }
    // Continue with location found...
});

解决方案

You could use a timeout to try to re-submit the form:

$('#route-form').submit(function(event) {
    // User submits form, we need their location...
    if(current_location==null) {
        toastMessage('Waiting for your location...');
        setTimeout(function(){ $('#route-form').submit(); }, 500); // Try to submit form after timeout
        return false;
    } else {
        // Continue with location found...
    }
});

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