EventSource 的响应具有不是“text/event-stream”的 MIME 类型（“text/html”）。 中止连接。 标头设置为文本/事件流

Question

Hi I get This error in my console using sse

EventSource's response has a MIME type ("text/html") that is not "text/event-stream". Aborting the connection.

js code is :

if (typeof(EventSource) !== "undefined") 
{
    var source = new EventSource("../api/updateWellData.php?uid=<?php echo $node_id ?>");
    source.onmessage = function(event) {
        var response = JSON.parse(event.data);
        document.getElementById("result").innerHTML = response.test;
        // some code like the above line
    };
}  
else 
{
    // refresh the page every 30 secs
} 

The PHP Code is :

header('Cache-Control: no-cache');
header("Access-Control-Allow-Origin: *");
header("Content-Type: text/event-stream");

require_once("../resources/config.php");

if (isset($_GET['uid']))
{
    $uid = $_GET['uid'];
    while (1) 
    {
        $query = Query("SELECT * FROM well_data_last WHERE well_detail_id = $uid");
        $result = fetch_array($query);
        echo json_encode($result);
        ob_end_flush();
        flush();
        sleep(1);
    }
}

This is my first time using sse I used the following documents : mozilla | w3schools

Answer 1

This error occurs when your PHP code outputs text in the wrong format.

This may be either a PHP error message (all of which are outputted as raw HTML), or some other text on the page which does not fit the text/event-stream format .

If the output of the PHP file does not match the format required by text/event-stream , it will fall back to using text/html . Javascript requires event streams use the text/event-stream content type so the JS console will show an error, but this is just a symptom of the actual problem - to fix the issue you need to fix your PHP.

---

In OP's case, the issue is with their echo statement. All data outputted to the stream must be proceeded by data: , and ended with a newline \\n . The stream itself must end with another newline to indicate that no more data: messages follow.

To fix the error, OP should change

echo json_encode($result);

to

echo "data: " . json_encode($result) . "\n\n";

---

Another issue with OP's code is that there is no protection against SQL-injection in the database query. While this is irrelevant to the issue at hand, it is worth pointing out that prepared statements should be used instead.

Answer 2

我遇到了同样的问题，问题是 php 文件中的语法错误，它显示了一条错误消息。