ng-trim
去掉前后空格 ，默认为false
<input type="text" name="" value="" ng-trim ng-model='a'>
等价于
<input type="text" name="" value="" ng-trim='true' ng-model='a'>
<div ng-app='test' ng-controller='con1'>
<form action="a.php" method="post">
<input type="text" name="" value="" ng-trim ng-model='a'>
<input type="text" name="aa" value="">
<input type="submit" name="" value="提交">
</form>
{{a}}
</div>
