Question

93

Unexpected token colon JSON after jQuery.ajax#get

rated 0 times [ 94] [ 1] / answers: 1 / hits: 15561 / 10 Years ago, thu, june 19, 2014, 12:00:00

I have created a minimalist API on nodejs which return data in JSON format.

But every time I try to make a ajax#get call and pass my API as URL, I will get an error and judging from Chrome, I'm getting a Unexpected token : error;

here the server code in nodejs + express:

var

 http    = require( 'http' ),

 express = require( 'express' ),

 app      = express(),

 server  = http.createServer( app );



app.get( '/', function( req, res ) {

    console.log( 'req received' );

        res.setHeader('Content-Type', 'application/json');

    res.end( JSON.stringify({

    Name : Tom,

    Description : Hello it's me!

    }) );



});



server.listen(3000, function() {

    console.log( 'Listening on 3000' );

});

The JSON returned from / is: {Name:Tom,Description:Hello it's me!}.

Here is my call from the client js:

$.ajax({

    url: findUrl,

    type: 'get',

    dataType: 'jsonp',

    success: function ( data ) {

        self.name( data.Name );

        self.description( data.Description );

    },

    error: function( jqXHR, textStatus, errorThrown ) {

        alert(errorThrown);

    }

});

When plotting the error I get: jQuery111108398571682628244_1403193212453 was not called

Can someone help me?

I know this question has been asked already but I haven't manage to find a solution which fix my program.

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kalias

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2 Years ago

answered 10 Years ago emanir · Accepted Answer

To support JSONP requests, the server will have to include the P, or Padding, in the response.

jQuery111108398571682628244_1403193212453({Name:Tom,Description:Hello it's me!})

The syntax error, Unexpected token :, is because JSONP is parsed as JavaScript, where {...} also represents blocks. It just takes advantage of JSON and JavaScript's similar syntax to define the data being passed to a global function call.

By default, jQuery will include a callback query-string parameter with the name of the function:

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);

}

ExpressJS also includes res.jsonp() that already implements this condition:

app.get( '/', function( req, res ) {

    console.log( 'req received' );



    res.jsonp({

        Name : Tom,

        Description : Hello it's me!

    });

});