Unexpected token colon JSON after jQuery.ajax#get
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.
Solution 1:
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!"
});
});