异步 javascript 发布请求的问题

Question

I am trying to simply set a ejs variable to data retrieved through an ajax post request every second. (refreshing a log) I have tried callback functions, and I feel like I am really close but can't seem to crack it.

Below is the javascript:

    function getResults(callback){     
        $.ajax({
            url: '/resultsRefresh',
            type: 'POST',
            async: true,
            cache: false,
            success: callback 
        })
    };

    function setResults(result) {
            console.log("result: " + result);
            document.getElementById("results") = result;
    };
    
    window.setInterval(getResults(setResults), 1000);

And this is the function in question being called on the node server:

function readResults(req, res) {
    return fs.readFileSync("./temp/results.txt", 'utf8');
}

which is coming through

webRouter.post("/resultsRefresh", readResults);

Any help/suggestions would be greatly appreciated.

Answer 1

When responding to requests in the server, you are generally not supposed to return a value, rather you need to call a response function. When using express, res.sendFile does the trick:

function readResults(req, res) {
    res.sendFile('./temp/results.txt');
}