How to know when Google places has loaded and is ready (asynchronously)?

问题

I load google maps and places asynchronously in JQuery :

 var script = document.createElement('script');
 script.type = 'text/javascript';
 script.src = "http://maps.google.com/maps/api/js?key=myKey&libraries=places&sensor=false&async=2&callback=MapApiLoaded";
 document.body.appendChild(script);

The callback is called when Google Maps has loaded :

function MapApiLoaded() {

   var input = document.getElementById('searchField');
   var options = {
      types: ['(cities)'],
   };

   autocomplete = new google.maps.places.Autocomplete(input, options);

   google.maps.event.addListener(autocomplete, 'place_changed', function(event) {
        var item = autocomplete.getPlace();
        // do some stuff
    }
    GMapsloaded = true;
 }

When I Get into my city selection screen, I check first that Google maps has been loaded :

 if(!GMapsloaded) {
    alert('mapsnotloaded');
    return;
  }

When my mobile is in Wifi or 3G, I can start typing in the placeholder and google places responds. When I'm in Edge, I start typing and there's no interaction from google places. It could take up to 2 minutes before I actually get any reaction when I type the first letter.

I'd like to only be able to actually start typing in the input text when Places is really ready. But I haven't found any event to bind to.

Any idea ? Thank you

回答1:

Found a solution. I hope it will help someone (I've spent 4 hours on this) :

// When Google places is ready, it adds an attr placeholder='Enter a location' or the equivalent in the current language
// It is the only way to know that it is monitoring the input field.
if (!GMapsloaded || $('#searchField').attr('placeholder') === undefined || $('#searchField').attr('placeholder') == false) {
    alert('Google places not attached to input');
    return;
}

来源：https://stackoverflow.com/questions/17135608/how-to-know-when-google-places-has-loaded-and-is-ready-asynchronously