Translating from JavaScript to Objective-C using JSON

Question

Translating from JavaScript to Objective-C using JSON

Can someone help me figure out how to correctly 'return' this JSON object in JavaScript?

function getJSONData() {   
                var points = '{\"points\": [';
                var params = polyline.getLatLngs();

                var i;
                for (i = 0; i < points.length; i++) {
                    params = params.concat('{\"latitude\": ', points[i].lat, ', \"longitude\": ', points[i].lng, '}');
                    if (i < points.length - 1) {
                        params = params.concat(', ');
                    }
                }
                params = params.concat('] }');

                return JSON.parse(params);
            }

I am looking to grab this data using something like the following Objective-C code:

NSString *jsonDataString = [self.webView stringByEvaluatingJavaScriptFromString:@"getJSONData();"];

However, I need the data to be in NSData format instead of NSString. How can I achieve this conversion properly in Objective-C?

NSData *jsonData = [jsonDataString dataUsingEncoding:NSUTF8StringEncoding];
NSDictionary *response = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONWritingPrettyPrinted error:&error];

Any suggestions on how to achieve this conversion from JSON as desired?

javascript objective-c json

Answer 1

Answer №1

Here is the solution:

function processData() {
    var data = shape.getCoordinates();
    var formattedData = [];
    var index;
    for (index = 0; index < data.length; index++) {
        formattedData.push({latitude: data[index].lat, longitude: data[index].long});
    }

    return JSON.stringify({points: formattedData});
}

Remember that JSON.parse converts a string to an object, while JSON.stringify changes an object into a string. You don't have to handle this manually.

Answer 2

Here is the solution:

function processData() {
    var data = shape.getCoordinates();
    var formattedData = [];
    var index;
    for (index = 0; index < data.length; index++) {
        formattedData.push({latitude: data[index].lat, longitude: data[index].long});
    }

    return JSON.stringify({points: formattedData});
}

Remember that JSON.parse converts a string to an object, while JSON.stringify changes an object into a string. You don't have to handle this manually.

Translating from JavaScript to Objective-C using JSON

Answer №1

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