axios-jsonp/lib/index.js

A jsonp adapter for axios

var cid = 1;

function buildParams(params) {
    var result = [];

    for (var i in params) {
        result.push(encodeURIComponent(i) + '=' + encodeURIComponent(params[i]));
    }

    return result.join('&');
}

module.exports = function jsonpAdapter(config) {
    return new Promise(function(resolve, reject) {
        var script = document.createElement('script');
        var src = config.url;

        if (config.params) {
            var params = buildParams(config.params);

            if (params) {
                src += (src.indexOf('?') >= 0 ? '&' : '?') + params;
            }
        }

        script.async = true;

        function remove() {
            if (script) {
                script.onload = script.onreadystatechange = script.onerror = null;

                if (script.parentNode) {
                    script.parentNode.removeChild(script);
                }

                script = null;
            }
        }

        var jsonp = 'axiosJsonpCallback' + cid++;
        var old = window[jsonp];
        var isAbort = false;

        window[jsonp] = function(responseData) {
            window[jsonp] = old;

            if (isAbort) {
                return;
            }
            
            var response = {
                data: responseData,
                status: 200
            }

            resolve(response);
        };

        var additionalParams = {
            _: (new Date().getTime())
        };
        
        additionalParams[config.callbackParamName || 'callback'] = jsonp;

        src += (src.indexOf('?') >= 0 ? '&' : '?') + buildParams(additionalParams);

        script.onload = script.onreadystatechange = function() {
            if (!script.readyState || /loaded|complete/.test(script.readyState)) {
                remove();
            }
        };

        script.onerror = function() {
            remove();

            reject(new Error('Network Error'));
        };

        if (config.cancelToken) {
            config.cancelToken.promise.then(function(cancel) {
                if (!script) {
                    return;
                }

                isAbort = true;

                reject(cancel);
            });
        }        

        script.src = src;

        document.head.appendChild(script);
    });
};