PHP array with JavaScript objects to JavaScript

Question

If I have an array in JS like this:

{
 "car": "BMW",
 "count": 7 
}

I can generate it from PHP quite easy using this array:

array(
       'car' => 'BMW',
       'count' => 7,
)

and json_encode. This is not a problem.

But what if I have an array in JS like this:

{
   "center": new google.maps.LatLng(-34.397, 150.644),
   "zoom": 8
}

is there also some nice way how to produce it from PHP?

The method above fails because JSON put quotes around "new google.maps.LatLng(-34.397, 150.644)".

Answer 1

JSON doesn't support custom types. It's just meant for passing data and to be available to any consumer, whereas google.maps.LatLng() isn't really "data."

So, you'll have to accomplish this in 2 steps:

1. You can include the values needed in another PHP array for the JSON:

   array(
       'center' => array(
           'lat' => -34.397,
           'lng' => 150.644
       ),
       'zoom' => 8
   )
   

   {
       "center": {
           "lat": -34.397,
           "lng": 150.644
       },
       "zoom": 8
   }
   

2. Then, once parsed to a JavaScript Object, say data:

   data.center = new google.maps.LatLng(data.center.lat, data.center.lng);
   

   And, if there are numerous examples of such objects in the data, you can specify a reviver function to try to recognize them and create the instances:

   // parse, creating `google.maps.LatLng` from any { lat: ..., lng: ..., ... }
   var data = JSON.parse(jsonString, function (key, value) {
       if (typeof value === 'object' && value.lat && value.lng) {
           return new google.maps.LatLng(value.at, value.lng);
       } else {
           return value;
       }
   });
   

   Example: http://jsfiddle.net/XXbUU/

---

Side note: JSON and JavaScript make a stronger distinction between "array" types than PHP does.

• "Associative" arrays in PHP become Objects in JSON and JavaScript.
• "Non-associative" arrays in PHP become Arrays in JSON and JavaScript.