How to Fix the \'Unexpected Token Colon JSON\' Error in jQuery.ajax#get?

Addressing the "Unexpected Token Colon JSON" Error in jQuery.ajax#get

In your attempt to retrieve JSON data from a minimalist API you created in Node.js, you encountered a "Unexpected token :" error in Chrome. This error typically occurs due to a mismatch between the expected and actual JSON response from the server.

When making an AJAX call using jQuery.ajax#get and specifying the dataType as 'jsonp', the server response requires a "padding" (P) to support JSONP requests. JSONP is a technique that allows cross-domain requests by wrapping the JSON data in a function call.

To resolve this issue, you need to modify the server-side code to include the padding in the response. In your Node.js code, add the following lines:

var callback = req.query.callback;
var data = JSON.stringify({
    Name : "Tom",
    Description : "Hello it's me!"
});

if (callback) {
    res.setHeader('Content-Type', 'text/javascript');
    res.end(callback + '(' + data + ')');
} else {
    res.setHeader('Content-Type', 'application/json');
    res.end(data);
}

Alternatively, if you are using Express.js, you can utilize the res.jsonp() method, which automatically handles the addition of the padding:

app.get( '/', function( req, res ) {
    console.log( 'req received' );

    res.jsonp({
        Name : "Tom",
        Description : "Hello it's me!"
    });
});

With these modifications, the server will send a JSONP response wrapped in a function call, which can be parsed by jQuery.ajax#get without encountering the "Unexpected token" error.

The above is the detailed content of How to Fix the 'Unexpected Token Colon JSON' Error in jQuery.ajax#get?. For more information, please follow other related articles on the PHP Chinese website!