initial file based on fanout's pubsub.js

1 files changed, 192 insertions, 0 deletions

diff --git a/polldance.js b/polldance.js
new file mode 100644
index 0000000..906aed6
--- /dev/null
+++ b/polldance.js
@@ -0,0 +1,192 @@
+// don't break if there's no console
+if(typeof(console) === "undefined")
+{
+	console = { log: function() {} };
+}
+
+var FO = FO || {};
+
+var fo_jsonp_callback_id = 0;
+var fo_jsonp_callbacks = {};
+
+function fo_jsonp_get_callback(cb_id)
+{
+	if(fo_jsonp_callbacks[cb_id])
+	{
+		return fo_jsonp_callbacks[cb_id];
+	}
+	else
+	{
+		console.log("no callback with id " + cb_id);
+		return function(result) {};
+	}
+}
+
+// FO.Request has onFinished(int code, object result) and onError(int reason) callback members
+// error reasons: 0=http, 1=timeout
+// note: failed json parse on http body results in empty object {}, not error
+
+FO.Request = function()
+{
+	if(!(this instanceof FO.Request))
+		throw new Error("Constructor called as a function");
+}
+
+FO.Request.prototype.start = function(method, url, headers, body)
+{
+	this._cors = false;
+	if("withCredentials" in new XMLHttpRequest())
+		this._cors = true;
+
+	var self = this;
+	this._timer = setTimeout(function() { self._timeout(); }, 60000);
+
+	if(this._cors)
+	{
+		this._xhr = new XMLHttpRequest();
+
+		this._xhr.onreadystatechange = function() { self._xhr_readystatechange(); };
+		this._xhr.open(method, url, true);
+
+		for(var key in headers)
+		{
+			if(!headers.hasOwnProperty(key))
+				continue;
+
+			this._xhr.setRequestHeader(key, headers[key]);
+		}
+
+		this._xhr.send(body);
+	}
+	else
+	{
+		var head = document.getElementsByTagName("head")[0];
+		var script = document.createElement("script");
+
+		script.type = "text/javascript";
+
+		this._cb_id = fo_jsonp_callback_id.toString();
+		++fo_jsonp_callback_id;
+
+		this._script_id = "fo-jsonp-script-" + this._cb_id;
+		script.id = this._script_id;
+
+		fo_jsonp_callbacks[this._cb_id] = function(result) { self._jsonp_callback(result); };
+
+		var param_list = new Array();
+
+		param_list.push("callback=" + encodeURIComponent("fo_jsonp_get_callback(\"" + this._cb_id + "\")"));
+		if(method != "GET")
+			param_list.push("method=" + encodeURIComponent(method));
+		if(headers)
+			param_list.push("headers=" + encodeURIComponent(JSON.stringify(headers)));
+		if(body)
+			param_list.push("body=" + encodeURIComponent(body));
+
+		var params = param_list.join("&");
+
+		var src;
+		if(url.indexOf("?") != -1)
+			src = url + "&" + params;
+		else
+			src = url + "?" + params;
+
+		script.src = src;
+		console.log("FO.Request json-p " + this._cb_id + " " + src);
+		head.appendChild(script);
+	}
+}
+
+FO.Request.prototype.abort = function()
+{
+	clearTimeout(this._timer);
+	this._timer = null;
+
+	this._cancelreq();
+}
+
+FO.Request.prototype._cancelreq = function()
+{
+	if(this._cors)
+	{
+		this._xhr.onreadystatechange = function() {}
+		this._xhr.abort();
+		this._xhr = null;
+	}
+	else
+	{
+		console.log("FO.Request json-p " + this._cb_id + " timeout");
+
+		delete fo_jsonp_callbacks[this._cb_id];
+		var script = document.getElementById(this._script_id);
+		script.parentNode.removeChild(script);
+		this._cb_id = null;
+		this._script_id = null;
+	}
+}
+
+FO.Request.prototype._xhr_readystatechange = function()
+{
+	if(this._xhr.readyState === 4)
+	{
+		clearTimeout(this._timer);
+		this._timer = null;
+
+		var status = this._xhr.status;
+		var responseText = this._xhr.responseText;
+		this._xhr = null;
+
+		if(status)
+		{
+			var result;
+
+			try
+			{
+				result = JSON.parse(responseText);
+			}
+			catch(e)
+			{
+				result = {}
+			}
+
+			this._finished(status, result);
+		}
+		else
+			this._error(0);
+	}
+}
+
+FO.Request.prototype._jsonp_callback = function(result)
+{
+	console.log("FO.Request json-p " + this._cb_id + " finished");
+
+	clearTimeout(this._timer);
+	this._timer = null;
+
+	delete fo_jsonp_callbacks[this._cb_id];
+	var script = document.getElementById(this._script_id);
+	script.parentNode.removeChild(script);
+	this._cb_id = null;
+	this._script_id = null;
+
+	this._finished(result.status, result.value);
+}
+
+FO.Request.prototype._timeout = function()
+{
+	this._timer = null;
+	this._cancelreq();
+	this._error(1);
+}
+
+FO.Request.prototype._finished = function(code, result)
+{
+	if(this.onFinished)
+		this.onFinished(code, result);
+}
+
+FO.Request.prototype._error = function(reason)
+{
+	if(this.onError)
+		this.onError(reason);
+}