构造 'WebSocket' 失败：URL '{{.}}' 无效

Question

gorilla/websocket 例子

在这个例子中：

https://github.com/gorilla/websocket/blob/e8629af678b7fe13f35dff5e197de93b4148a909/examples/echo/server.go#L79

WebSocket 创建者：

ws = new WebSocket("{{.}}");

示例运行良好。

问题

但是，我想在另一个 JS 代码中使用相同的代码，例如：

var ws;
ws = new WebSocket("{{.}}");
ws.onopen = function(evt) {
    console.log("OPEN SOCKET");
}
ws.onclose = function(evt) {
    console.log("CLOSE SOCKET");
    ws = null;
}
ws.onmessage = function(evt) {
    console.log("RESPONSE SOCKET: RECEIVED");
}
ws.onerror = function(evt) {
    console.log("ERROR: " + evt.data);
}
ws.send(positions);
ws.close();

我收到此错误：

Uncaught (in promise) DOMException: Failed to construct 'WebSocket': The URL '{{.}}' is invalid. at AddObjectCommand.execute

我这样更改了 WebSocket：

ws = new WebSocket("ws://127.0.0.1:8080/echo");

但我仍然收到错误消息：

WebSocket connection to 'ws://127.0.0.1:8080/echo' failed: Error during WebSocket handshake: Unexpected response code: 403

我不知道我做错了什么。我错过了什么？

修复403

此建议解决了 403 错误：

https://github.com/gorilla/websocket/issues/367#issuecomment-375971418

通过添加：

upgrader.CheckOrigin = func(r *http.Request) bool { return true }

之前：

c, err := upgrader.Upgrade(w, r, nil)

当然，相信所有来源并不安全。只是临时修复。

又一个错误

但是抛出另一个错误：

Uncaught (in promise) DOMException: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state.

Answer 1

错误：

Uncaught (in promise) DOMException: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state.

通过 WebSocket 发送数据，通过其 .onopen 回调解决：

var positions = ...

var ws;
ws = new WebSocket("ws://127.0.0.1:8080/echo");
ws.onopen = function(evt) {
    console.log("OPEN SOCKET");
    console.log("SEND: START");
    ws.send(positions);
    ws.close();
}