textarea val（）使用jquery编辑和删除字符串

i'm creating a link sharing that on bind() events of a specific textarea ( where i paste links ) it does an $.post ajax callback with a preview (in case of youtube or vimeo link). Basically, i would remove link into textarea each times that link is detected and preview is gotten.

this is the function that does the callback :

    $('#writer').bind('change keypress keyup keydown',function() {

   var value_= $('#writer').val();
            $('#thumb-temp').hide();


            $.post( 'checklink.php?', { string : value_ }, 
            function(response) {
                $('.writer').prepend(response);
                $('#thumb-temp').show();

    }).fail(function() { alert( "error" ) })
});

and the page checklink.php that should remove the link

<?
    $link = $_POST['string'];

            $reg_exUrl = "/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";
            preg_match($reg_exUrl, $link, $url);

            $link = $url[0];
?>
<script>clearTextarea('<? echo $link ?>')</script>

and in the end the clearTextarea() function

function clearTextarea(url) {
var _textarea = $('#writer');
var _curVal     =   _textarea.val();
        var _curUrl =   url;
        var _regex      =   new RegExp( _curUrl , 'g' );
        var _newVal     =   _curVal.replace( _regex , '' );

        _textarea.val( _newVal );
}

Now, apparentely, this should works but nothing happens, any ideas ? I do not understand where I'm wrong :(

I'm not sure if you can run javascript that way (echoing from PHP). I would call it from the $.post directly.

First of all, I will suggest you not to send the ajax so many times. Regex is basically what you can do in JS as well. So instead of sending ajax - check for links in your JS code. Second, if you want to change the value of textarea, you should use html() instead of val().

The Order should be,

  <script type="text/javascript">       

        function clearTextarea(url) { 
                var _textarea = $('#writer');
                var _curVal     =   _textarea.val();
                        var _curUrl =   url;
                        var _regex      =   new RegExp( _curUrl , 'g' );
                        var _newVal     =   _curVal.replace( _regex , '' );

                 _textarea.val( url );
        }
    </script>

Textarea in HTML:

  <textarea id="writer"></textarea>

PHP code

          <?php
             $link = $_POST['string'];

            $reg_exUrl = "/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/";
            preg_match($reg_exUrl, $link, $url);

            $link = $url[0];

        ?>

Calling clearTextarea function();

   <script>clearTextarea('<?php echo $link ?>');</script>

i solved in this way

function clearTextarea() {
        var _textarea = $('#writer');
        var _curVal     =   _textarea.val();
        var _curUrl     =   _curVal.match(/(http|https|ftp|ftps)\:\/\/[a-zA-Z0-9\-\.]+\.[a-zA-Z]{2,3}(\/\S*)?/gi);

        var _newVal     =   _curVal.replace( _curUrl , '' );

        _textarea.val(_newVal);
}

and call clearTextarea() on ajax complete. That's it ;D