一个基于jquery的文本框记数器_JavaScript

一个基于jquery的文本框记数器

代码如下:

/*
*长度跟踪器
*v2.1.0
*bind2id:用于显示长度变化的元素的id
*max:最大长度
*msgwrap:提示信息(必须要有一个"-"占位符)
*eg:$('#input').lentracer({bind2id:'mytracer',max:150,msgwrap:'您还可以输入-个字符'});
*author:liujg1015@gmail.com
*/
(function ($) {
var zw_validate = function (el, option) {
this.el = $(el);
this.bindel = false;
this.setting = {
bind2id: false,
max: 100,
msgwrap: '您还可以输入-个字符'
};
if (option) {
$.extend(this.setting, option);
this.init();
}
};
zw_validate.prototype = {
init: function () {
var _this = this;
this.bindel = $('#' + this.setting.bind2id);
this.el.focus(function () { _this.start(); }).blur(function () { _this.dispose(); });
this.el.css({ paddingbottom: 20 });
this.initmsg();
},
initmsg: function () {
var wrap = this.setting.msgwrap.split('-');
this.bindel.text(this.setting.max - this.count().total).before(wrap[0]).after(wrap[1]);
},
count: function () {
var _val = this.el.val();
var _len = _val.length;
var _rowcount = 0;
var _enterlen = 0;
var _partten = /\n+/g;
if (_len > 0 && _partten.test(_val)) {
_enterlen += 3;
while ((result = _partten.exec(_val)) != null) {
if ((result.index + 1 + _enterlen) > this.setting.max) {
break;
}
_enterlen += 3;
}
_rowcount = _val.match(_partten).length;
}
return { total: (_len + _rowcount * 3), enterlen: _enterlen };
},
start: function () {
var _this = this;
_this.timer = setinterval(function () {
var _val = _this.el.val();
var _rlt = _this.count();
if (_rlt.total > _this.setting.max) {
if (_rlt.enterlen > 0) {
_this.el.val(_val.substr(0, _this.setting.max - _rlt.enterlen));
}
else {
_this.el.val(_val.substr(0, _this.setting.max));
}
_this.bindel.text(_this.setting.max - _this.count().total);
return;
}
_this.bindel.text(_this.setting.max - _rlt.total);
}, 300);
},
dispose: function () {
clearinterval(this.timer);
},
restore: function () {
this.bindel.text(this.setting.max - this.el.val().length);
}
};
$.fn.extend({
lentracer: function (option) {
return new zw_validate(this, option);
}
});
})(jquery);

一、上面是计数器的脚本，可将脚本贴到js文件中，然后在html里面添加引用。

. 代码如下:

<html>
<head>
<title>demo</title>
</head>
<body>
<table>
<tr>
<td>
标题
</td>
<td>
<input type="text" id="title" />
<span id="titlelen"></span>
</td>
</tr>
<tr>
<td>
评论
</td>
<td>
<textarea cols="5" rows="5" id="comment"></textarea>
<span id="commentlen"></span>
</td>
</tr>
</table>
<script src="../scripts/jquery.js" type="text/javascript"></script>
<script src="../scripts/lentracer.js" type="text/javascript"></script>
<script type="text/javascript">
$(document).ready(function(){
$('#title).lentracer({ bind2id: titlelen, max: 50});
$('#comment).lentracer({ bind2id: commentlen, max: 200, msgwrap: '剩余-字' });
});
</script>
</body>
</html>