X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=public%2Fjavascripts%2Futils%2Fajax.js;fp=public%2Fjavascripts%2Futils%2Fajax.js;h=ab288bc77c7aa32a64fccc8462e50efccd9a40ab;hb=da06a6eb0237123ce43fdb01cb06246b8b57f5e5;hp=0000000000000000000000000000000000000000;hpb=4ecf423bce243e8e10b5b777a95f67ecc9f8d8d3;p=vchess.git

diff --git a/public/javascripts/utils/ajax.js b/public/javascripts/utils/ajax.js
new file mode 100644
index 00000000..ab288bc7
--- /dev/null
+++ b/public/javascripts/utils/ajax.js
@@ -0,0 +1,55 @@
+// From JSON (encoded string values!) to "arg1=...&arg2=..."
+function toQueryString(data)
+{
+	let data_str = "";
+	Object.keys(data).forEach(k => {
+		data_str += k + "=" + data[k] + "&";
+	});
+	return data_str.slice(0, -1); //remove last "&"
+}
+
+// data, error: optional
+function ajax(url, method, data, success, error)
+{
+	let xhr = new XMLHttpRequest();
+	if (typeof(data) === "function") //no data
+	{
+		error = success;
+		success = data;
+		data = {};
+	}
+	if (!error)
+		error = errmsg => { alert(errmsg); };
+
+	xhr.onreadystatechange = function() {
+		if (this.readyState == 4 && this.status == 200)
+		{
+			try {
+				let res_json = JSON.parse(xhr.responseText);
+				if (!res_json.errmsg)
+					success(res_json);
+				else
+					error(res_json.errmsg);
+			} catch (e) {
+				// Plain text (e.g. for rules retrieval)
+				success(xhr.responseText);
+			}
+		}
+	};
+
+	if (["GET","DELETE"].includes(method) && !!data)
+	{
+		// Append query params to URL
+		url += "/?" + toQueryString(data);
+	}
+
+	xhr.open(method, url, true);
+	xhr.setRequestHeader('X-Requested-With', "XMLHttpRequest");
+	if (["POST","PUT"].includes(method))
+	{
+		xhr.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
+		xhr.send(JSON.stringify(data));
+	}
+	else
+		xhr.send();
+}