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Question

Is it possible to duplicate the native behavior of JavaScript's prompt()?

Answer 1

+5 A:

No, it is not possible to duplicate this behavior. The way to achieve the same effect is to use a callback in your code, so you can do something like:

myPrompt('Hello, mate, whats yer name?', function(answer) {
   alert(answer);
});

EDIT: Based on your code, why not do this?

<body>
<div id="prompt" style="display: none;">
<input type="text" id="q" /> <input type="button" value="OK" id="ok" />
</div>
<script>
$ = function(i) {return document.getElementById(i);}

_prompt = function(prompt, callback) {
    $('prompt').style.display = '';
    $('q').value = '';
    $('ok').onclick = function() {
        callback($('q').value);
    }
}

_prompt('Name?', function(answer) {
    alert(answer);  
});
</script>
</body>

If you change alert(answer); to say... gAnswer = answer; (notice no var declaration) you would be creating a global variable named gAnswer that you could access anywhere else in the javascript code, assuming the prompt was already answered. If you're concerned of global variables polluting your space you could wrap it all in a closure, but it should be fine otherwise.

Paolo Bergantino 2009-03-23 14:34:38

Ack! Just as I figured... so there's no way to store the value for later use, then, huh?

Hexagon Theory 2009-03-23 14:42:18

You could, what are you trying to accomplish? If you make the variable global and set it inside the callback you could access it later.

Paolo Bergantino 2009-03-23 14:45:59

That's the thing, mate... you can't. : (

Hexagon Theory 2009-03-23 14:49:13

Yes you can... can you post what you are trying?

Paolo Bergantino 2009-03-23 14:53:36

You can code myPrompt() to return the value that the user input. As a result, you'll have `var c = myPrompt(...)`, and you can then use `c` anywhere else without resorting to global variables.

Ron DeVera 2009-03-23 15:00:08

While definitely an improvement, your implementation still doesn't allow me to access the answer in some future portion of my code... erm, does it?

Hexagon Theory 2009-03-23 15:20:40

+1 love your first example

alex 2009-04-14 01:54:32

Answer 2

A:

@Paolo:

This is the code I am currently working with:

<body>
<div id="prompt" style="display: none;">
<input type="text" id="q" /> <input type="button" value="OK" id="ok" />
</div>
<script>
$ = function(i) {return document.getElementById(i);}
_prompt = function(q, e)
 {
    $('prompt').style.display = '';
    $('q').value = '';
    $('ok').setAttribute('onclick', e + ' $("prompt").style.display = "none";');
 }
var c; _prompt('Name?', 'c = $("q").value;');
alert(c);
</script>
</body>

Now, as would be expected, that alert() fires as soon as the page is loaded, which is most definitely not what I want; ideally, I'd like for the rest of the code to wait for the prompt to get handled, but I'm strongly doubting this is possible outside of the native implementation. Reckon I'll just have to settle for designing my algorithm so that the prompt gets used immediately?

Hexagon Theory 2009-03-23 15:04:02

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Is it possible to duplicate the native behavior of JavaScript's prompt()?

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