how can i retrieve a current value of textarea?

问题

Problem : So I have alerted the value of textarea by:

var source = document.getElementById('source').value;
            alert(source);

But the value of textarea is alerted as it was at the time of page load. And I want to alert current value of the textarea. I have also tried

$("form").submit(function(){

But that also haven't helped me. So how can I do this?

This is my code.

<html>
    <head>
    <title>Perl WEB</title>
    <script type="text/javascript" src="http://code.guru99.com/Perl1/codemirror.js"></script>
    <link rel="stylesheet" href="http://code.guru99.com/Perl1/codemirror.css" type="text/css" media="screen" />
    <script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
    <script type="text/javascript" src="http://code.guru99.com/perl/perl.js"></script>
    <style>
    .CodeMirror {
    border: 1px solid #eee;
    }   
    .CodeMirror-scroll {
    height: auto;
    overflow-y: hidden;
    overflow-x: auto;
    }
</style>
<script>
$(document).ready(function(){
  $("form").submit(function(){
    alert("Submitted");
  });
});
</script>
<script type="text/javascript">

    function execute() {
            p5pkg.CORE.print = function(List__) {
                var i;
                for (i = 0; i < List__.length; i++) {
                  document.getElementById('print-result').value += p5str(List__[i])
                }
                return true;
            };
            p5pkg.CORE.warn = function(List__) {
                var i;
                List__.push("\n");
                for (i = 0; i < List__.length; i++) {
                    document.getElementById('log-result').value += p5str(List__[i]);
                }
                return true;
            };
            p5pkg["main"]["v_^O"] = "browser";
            p5pkg["main"]["Hash_INC"]["Perlito5/strict.pm"] = "Perlito5/strict.pm";
            p5pkg["main"]["Hash_INC"]["Perlito5/warnings.pm"] = "Perlito5/warnings.pm";

            var source = document.getElementById('source').value;
            alert(source);
            var pos = 0;
            var ast;
            var match;
            document.getElementById('log-result').value   = "";
        //  document.getElementById('js-result').value    = "";
            document.getElementById('print-result').value = "";
            try {
                // compile
                document.getElementById('log-result').value += "Compiling.\n";
                var start = new Date().getTime();
                var js_source = p5pkg["Perlito5"].compile_p5_to_js([source]);
                var end = new Date().getTime();
                var time = end - start;
                document.getElementById('log-result').value +=  "Compilation time: " + time + "ms\n";
        //      document.getElementById('js-result').value  += js_source + ";\n";

                // run
                start = new Date().getTime();
                eval(js_source);
                end = new Date().getTime();
                time = end - start;
                document.getElementById('log-result').value += "Running time: " + time + "ms\n";

                p5pkg.CORE.print(["\nDone.\n"]);
            }
            catch(err) {
                document.getElementById('log-result').value += "Error:\n";
                document.getElementById('log-result').value += err + "\n";
                document.getElementById('log-result').value += "Compilation aborted.\n";
                  }
        }
    </script>
    </head>
    <body>
    <form>
<textarea id="source" cols="70" rows="10">
say 'h';
</textarea>
    <div class="hint">This code is editable. Click Run to execute.</div>
    <input type="button" value="Run" onclick="execute()"/></br>
Output:</br>
    <textarea id="print-result" disabled="true" rows="10" cols="70"></textarea></br>
Log:</br>
    <textarea  id="log-result" disabled="true" cols="70"></textarea>
    <script>
      var editor = CodeMirror.fromTextArea(document.getElementById("source"), {
        lineNumbers: true,
        indentUnit: 4,
        indentWithTabs: true,
        enterMode: "keep",
        tabMode: "shift"
      });
    </script>
</form>
    </body>
</html>

So how can I get the current value of the textarea? Please help me guys.

回答1:

I'm not familiar with CodeMirror, but what you exactly see on the screen, is not your original #source anymore. Instead there are several elements created by CodeMirror, and the original textarea is hidden.

When I look at the documentation, I found this:

var source = editor.doc.getValue();
alert(source);

Or, since you've constructed the editor object with fromTextArea() method, you can update the value of the the textarea before reading it:

editor.save();
var source = document.getElementById('source').value;           
alert(source);

Notice also what Adam has said about submitting the form. And there are invalid </br> tags in your HTML, the correct form is <br />.

Please visit at CodeMirror User Manual for the furher information.

回答2:

As you have jQuery loaded you can do as follows:

var content = $('#source').val();
alert(content);

Of course, if you do it at page load, the textarea will be empty (or even uncreated). You could extract its content on form submit, as you seem to suggest.

This code will create a button that will alert the content of your textarea when clicked:

<button onclick="alert($('#source').val())">Click me</button>

回答3:

Try the following inside the submit()

var textAreaVal = $("#print-result").val();
alert(textAreaVal);

回答4:

Your form does not get submitted when the button in it is pressed since this is not a submit button.

This will not submit the form, and will not alert its' contents.

<input type="button" value="Run" onclick="execute()"/></br>

Add something like this in the form:

<input type="submit" value="Submit">

回答5:

if yout want the value to alert when the mouse leaves the textarea you could try to add onblur="myFunction()" to the input something like: (actually if you want it on mouse leave, you can add onmouseout="myFunction()")

<textarea id="source" cols="70" rows="10" onblur="myFunction()">
    say 'h';
</textarea>


<script type="text/javascript">
    function myFunction() {
        var source = document.getElementById('source').value;
        alert(source);
    }
</script>

来源：https://stackoverflow.com/questions/17523851/how-can-i-retrieve-a-current-value-of-textarea

标签

javascript

html

codemirror