53 lines
1.1 KiB
JavaScript
53 lines
1.1 KiB
JavaScript
/**
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* Module dependencies
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*/
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var XMLHttpRequest = require('xmlhttprequest-ssl');
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var XHR = require('./polling-xhr');
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var JSONP = require('./polling-jsonp');
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var websocket = require('./websocket');
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/**
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* Export transports.
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*/
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exports.polling = polling;
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exports.websocket = websocket;
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/**
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* Polling transport polymorphic constructor.
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* Decides on xhr vs jsonp based on feature detection.
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*
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* @api private
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*/
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function polling (opts) {
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var xhr;
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var xd = false;
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var xs = false;
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var jsonp = false !== opts.jsonp;
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if (typeof location !== 'undefined') {
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var isSSL = 'https:' === location.protocol;
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var port = location.port;
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// some user agents have empty `location.port`
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if (!port) {
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port = isSSL ? 443 : 80;
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}
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xd = opts.hostname !== location.hostname || port !== opts.port;
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xs = opts.secure !== isSSL;
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}
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opts.xdomain = xd;
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opts.xscheme = xs;
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xhr = new XMLHttpRequest(opts);
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if ('open' in xhr && !opts.forceJSONP) {
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return new XHR(opts);
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} else {
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if (!jsonp) throw new Error('JSONP disabled');
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return new JSONP(opts);
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}
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}
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