JSONP in NPM module (Node/Browser) Cross domain

Question

I'm writing an NPM module supposed to work both in Node and on the browser (packed via Browserify).

Part of its functionality is to execute a JSONP call, and to return the parsed data. I can't get it to work. I tried using the jsonp-client and jsonp npm modules, to little avail.

node-jsonp : https://www.npmjs.com/package/node-jsonp

promise = new promise (resolve, reject) ->

        nodejsonp url, (json) ->
            resolve json

The snippet above works fine in Node, but in the browser fails because of the Same Origin cross domain security policy.

jsonp-client https://www.npmjs.com/package/jsonp-client

promise = new promise (resolve, reject) ->
        jsonpclient url, (err, data) ->
            if (err)
                console.log err
            resolve data

In this case I get the error "Error: Could not find callback on URL(…)", but I can't understand from the documentation how to properly implement the functionality.

Little help? :)

Edit: The first package mentioned is actually "node-jsonp" and not "jsonp"

Answer 1

Looks like you use their API incorrect. Api for first one package is: jsonp(url, opts, fn) , so you should rewrite your code and add opts:

promise = new promise (resolve, reject) ->
    jsonp url, {}, (json) ->
        resolve json

Second one have this in documentation:

On the browser you must supply a valid callback on the URL.

It requires manual adding of callback parameter to URL. You should check how jsonp works : it adds callback GET parameter and response wrapped in calling of this callback function. Ie

• you are sendind request: <api url>?callback=cb ;
• server renders javascript response, that will be eval -ed in your application cb({json});
• for handling of this response you should have global function cb , that will receive json as argument.