<div class="intro">
<p>
    This example shows how to use the `reviver` parameter in `JSON.parse()` to add new object members and format existing members during the parsing phase.
</p>
</div>

<div class="example yui3-skin-sam">
    {{>json-convert-values-source}}
</div>

<h2>The Data</h2>
<p>
    The data returned from the server will be a JSON string containing this object structure:
</p>

```json
[
    {"SKU":"23-23874", "Price":23.99,  "Item":"Helmet"},
    {"SKU":"48-38835", "Price":14.97,  "Item":"Football"},
    {"SKU":"84-84848", "Price":3.49,   "Item":"Goggles"},
    {"SKU":"84-84843", "Price":183,    "Item":"Badminton Set"},
    {"SKU":"84-39321", "Price":6.79,   "Item":"Tennis Balls"},
    {"SKU":"39-48949", "Price":618,    "Item":"Snowboard"},
    {"SKU":"99-28128", "Price":78.99,  "Item":"Cleats"},
    {"SKU":"83-48281", "Price":4.69,   "Item":"Volleyball"},
    {"SKU":"89-32811", "Price":0.59,   "Item":"Sweatband"},
    {"SKU":"28-22847", "Price":779.98, "Item":"Golf Set"},
    {"SKU":"38-38281", "Price":8.25,   "Item":"Basketball Shorts"},
    {"SKU":"82-38333", "Price":1.39,   "Item":"Lip balm"},
    {"SKU":"21-38485", "Price":0.07,   "Item":"Ping Pong ball"},
    {"SKU":"83-38285", "Price":3.99,   "Item":"Hockey Puck"}
]
```

<h2>Create a `reviver` function</h2>
<p>
    We'll contain all the moving parts in an `example` namespace. In it, we'll include the currency exchange rates and a function to reference the rates to add a new member to the JSON response as it is being parsed.
</p>

```
YUI().use("node", "io", "json-parse",function (Y) {

var example = {
    rates : {"USD":1,"EUR":0.6661,...,"COP":2000 ,"ARS":3.1289},

    currency : 'USD', // updated by the select element

    convert : function (k,v) {
        // 'this' will refer to the object containing the key:value pair,
        // so this step will add a new object member while leaving the original
        // intact (but formatted to two decimal places).  If the original
        // is not needed, just return the converted value.
        if (k === 'Price') {
            var x = Math.round(v * example.rates[example.currency] * 100) / 100;
            this.convertedPrice = x.toFixed(2); // added to item
            return v.toFixed(2); // assigned to item.Price
        }
        return v;
    },
    …
};
…
```

<h2>Sending the request and parsing the JSON response</h2>
<p>
    When the <em>Get Data</em> button is clicked, we send an io request for the JSON data, and in our `success` handler, pass our conversion function to `JSON.parse()` with the response text. The resulting inventory records will have an additional member, `convertedPrice`. This data is then passed to a UI method to update the inventory table.
</p>

```
Y.one('#demo_go').on('click', function (e) {
    // Disable the button temporarily
    this.set('disabled',true);

    // Store the requested currency
    var sel = Y.one("#demo select");
    example.currency = sel.get("options").item(sel.get("selectedIndex")).get("value");

    // Send the request for the JSON data
    Y.io('{{componentAssets}}/json-convert-values-response.json',{
        timeout : 3000,
        on : {
            success : function (xid, res) {
                var inventory;
                try {
                    inventory = Y.JSON.parse(res.responseText,example.convert);

                    example.updateTable(inventory);
                }
                catch(e) {
                    alert("Error getting inventory data");
                }
                finally {
                    Y.one('#demo_go').set('disabled',false);
                }
            },
            failure : function () {
                alert("Error getting inventory data");
            }
        }
    });
});

}); // End YUI(..).use(..,function (Y) {
```

<h2>Complete Example Source</h2>

```
{{>json-convert-values-source}}
```