analyze.js

function Nest(api_key) {
    this.api_key = api_key;
}

Nest.prototype = {
    analyzeFile: function(file, type, options) {
        var form = new FormData();
        form.append('api_key', this.api_key);
        form.append('track', file);
        form.append('filetype', type);
        form.append('bucket', 'audio_summary');
        var request = new XMLHttpRequest();
        request.open('POST', 'http://developer.echonest.com/api/v4/track/upload');
        request.onload = function (e) {
            var result = JSON.parse(request.responseText);
            result.response.track.audio_summary.analysis_url = 'http://developer.echonest.com' + result.response.track.audio_summary.analysis_url.substr(46);
            options.onload(result);
        }
        request.onerror = function (e) {
            options.onerror(e);
        }
        request.send(form);
    },
    
    loadAnalysis: function (url, options) {
        var request = new XMLHttpRequest();
        request.open('GET', url);
        request.onload = function (e) {
            options.onload(JSON.parse(request.responseText));
        }
        request.onerror = function (e) {
            options.onerror();
        }
        request.send();
    }
};