Why won't Appcelerator Titanium Mobile parse this JSON?-Collection of common programming errors

2 years ago

admin

2 minutes

Using 1.4.1 against Android under Windows 7. I have a web service being access from the Titanium application, the service returns JSON like this:

{
    "VFPData": {
        "rows": [
            {
                "address1": "Orion House",
                "address2": "Orion Way",
                "address3": "Kettering",
                "address4": "Northants",
                "comp_name": "Orion Vehicles Leasing",
                "contid": 1,
                "email": "",
                "email2": "",
                "fax": "",
                "firstname": "David John",
                "lastname": "Sear",
                "mobile": "",
                "phone1": "",
                "phone2": "",
                "postcode": "NN15 6PE"
            },
            {
                "address1": "Unit 20 Acton Business Park",
                "address2": "Acton Lane",
                "address3": "London",
                "address4": "",
                "comp_name": "Orion Vehicles Limited",
                "contid": 2,
                "email": "[email protected]",
                "email2": "",
                "fax": "",
                "firstname": "Mark",
                "lastname": "Johnson",
                "mobile": "0888 566 67879",
                "phone1": "0208 209 1359",
                "phone2": "",
                "postcode": "NW10 7NH"
            }
        ]
    }
}

However no combination of eval or JSON.parse will return a valid result – for example:

var contacts = JSON.parse(this.responseText);
alert(contacts.length);

That will show an alert dialog with nothing in it. The Titanium HTTPClient calls are working fine as I can

Ti.debug(this.responseText)

with no problem.

That JSON validates OK as well, in jsonlint.com for example.

The JSON looks fine, and parses fine… but is the line:
```
alert(contacts.length);
```
the only part that leads you to believe it isn’t working? Because you can’t get the length of an object (VFPData)… you’ll get undefined/null whether valid parsing happened or not. A better test is:
```
alert(contacts.VFPData.rows.length);
```
… since you know rows is an array. Or:
```
alert(contacts);
```
Which should report it’s an object (if parsed) or null/undefined otherwise.

Originally posted 2013-11-09 22:47:44.