Re^7: webperl: fetching data over the web

> There is obviously something very inefficient going on with the <textarea>, I'll take a guess that it's this line: ta.value = ta.value + str;.

I've testet it in pure JS inside your webperl/plack environment.

Adding the whole of emperl.js to a textarea works without problem in my FF.

But appending 3000 lines in a loop creates an "out of memory" exception (adding only half the lines still works)

So buffering output (think $| ) might be a solution.

I'm expecting your ta.scrollTop = ta.scrollHeight; to mean even more trouble. *

<!doctype html>
<html lang="en-us">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8"
+>
    <title>WebPerl &lt;script&gt; Demos</title>



    <script type="text/javascript">

function xfetch(url) {
    var req = new XMLHttpRequest();
    req.open('GET', url , false);
    req.send(null);
    if(req.status == 200) {
        return req.responseText;
    } else {
        return "";
    }
}


    </script>


  </head>
  <body>

    <textarea id="test" cols=100 rows=80>
    </textarea>

    <script>
    
var data = xfetch('http://localhost:5000/emperl.js');
var ta   = document.getElementById("test");

// --- add one big chunk
//ta.value += data;

// --- add line by line
var lines = data.split(/;/);
ta.value += "lines.length: " + lines.length + "\n\n\n";
if (true)
    for (var i=0; i<lines.length; i++)
        ta.value+=lines[i]+";";

    </script>
    
  </body>
</html>
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery
FootballPerl is like chess, only without the dice}

*) indeed scrolling makes the whole unresponsive with much smaller line-counts already.

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Re^8: webperl: fetching data over the web by haukex (Archbishop) on Nov 11, 2018 at 08:53 UTC
What's even worse is that Emscripten may decide to provide the STDOUT stream on a character-by-character basis! (I don't think there's a clear spec on its behavior, i.e. whether it's characters or blocks.)	[reply]