Extract postcode from Google Maps API JSON using Google Refine

I'm trying to use Google Refine to extract postcodes from Google Maps API JSON.

I added a new column by fetching URLs:

"http://maps.googleapis.com/maps/api/geocode/json?sensor=false&address=" + escape(value, "url")

Then the resulting JSON is as follows:

{ "results" : [ { "address_components" : [ { "long_name" : "44", "short_name" : "44", "types" : [ "street_number" ] }, { "long_name" : "Homer Street", "short_name" : "Homer St", "types" : [ "route" ] }, { "long_name" : "London", "short_name" : "London", "types" : [ "locality", "political" ] }, { "long_name" : "Greater London", "short_name" : "Gt Lon", "types" : [ "administrative_area_level_2", "political" ] }, { "long_name" : "United Kingdom", "short_name" : "GB", "types" : [ "country", "political" ] }, { "long_name" : "W1H 4NW", "short_name" : "W1H 4NW", "types" : [ "postal_code" ] }, { "long_name" : "London", "short_name" : "London", "types" : [ "postal_town" ] } ], "formatted_address" : "44 Homer Street, London, Greater London W1H 4NW, UK", "geometry" : { "location" : { "lat" : 51.51981750, "lng" : -0.16534040 }, "location_type" : "ROOFTOP", "viewport" : { "northeast" : { "lat" : 51.52116648029151, "lng" : -0.1639914197084980 }, "southwest" : { "lat" : 51.51846851970851, "lng" : -0.1666893802915020 } } }, "types" : [ "street_address" ] } ], "status" : "OK" }

After browsing through a few blogs to find the relevant code, I then tried transforming the column using this...

value.parseJson().results[0]["formatted_address"]

...which works great for the full address.

The problem occurs when I try to extract the postcode. I tried fiddling around and got nowhere, then I downloaded JSONPad and pasted the JSON into a tree map to get the path:

value.parseJson().results[0]["address_components"][5]["long_name"]

The problem is that this extracts the postcode perfectly for some entries, and not so perfectly for others, where it extracts something else - town or country, for example.

Changing the [5] to [6] seems to extract the postcodes for the other addresses, but is there a way to extract ONLY the postcode, regardless of where it falls in the structure?

Any help much appreciated!

What you'd probably have to do is loop over the structs in the address_components array, checking the "types" of each one. When types contains "postal_code", then tada, that's your postcode.

Something like the following code (which worked for me):

<script type="text/javascript">
var stuData = 
{
    "results": [{
            "address_components": [{
                    "long_name": "44",
                    "short_name": "44",
                    "types": ["street_number"]
                }, {
                    "long_name": "Homer Street",
                    "short_name": "Homer St",
                    "types": ["route"]
                }, {
                    "long_name": "London",
                    "short_name": "London",
                    "types": ["locality", "political"]
                }, {
                    "long_name": "Greater London",
                    "short_name": "Gt Lon",
                    "types": ["administrative_area_level_2", "political"]
                }, {
                    "long_name": "United Kingdom",
                    "short_name": "GB",
                    "types": ["country", "political"]
                }, {
                    "long_name": "W1H 4NW",
                    "short_name": "W1H 4NW",
                    "types": ["postal_code"]
                }, {
                    "long_name": "London",
                    "short_name": "London",
                    "types": ["postal_town"]
                }
            ],
            "formatted_address": "44 Homer Street, London, Greater London W1H 4NW, UK",
            "geometry": {
                "location": {
                    "lat": 51.51981750,
                    "lng": -0.16534040
                },
                "location_type": "ROOFTOP",
                "viewport": {
                    "northeast": {
                        "lat": 51.52116648029151,
                        "lng": -0.1639914197084980
                    },
                    "southwest": {
                        "lat": 51.51846851970851,
                        "lng": -0.1666893802915020
                    }
                }
            },
            "types": ["street_address"]
        }
    ],
    "status": "OK"
};

var myPostcode;

for (var i = 0; i < stuData.results[0].address_components.length; i++) {
    for (var j = 0; j < stuData.results[0].address_components[i].types.length; j++) {
        if (stuData.results[0].address_components[i].types[j] == "postal_code") {
            myPostcode = stuData.results[0].address_components[i].long_name;
            break;
        }
    }
}

console.log(myPostcode);
</script>