angular 基于ng-messages的表单验证实例

 <div class="form-group" ng-class="{'has-error': myform.myname.$touched && myform.myname.$invalid}">
  <label class="col-xs-2 control-label">name</label>
  <div class="col-xs-6">
    <input type="text" class="form-control" name="myname" ng-model="formdata.username"
        placeholder="2-10个中英文字符，aaa会重名，必填"
        name-check minlength="2" maxlength="10" required>
  </div>
  <div class="col-xs-4 form-control-static text-danger" ng-messages="myform.myname.$error"
           ng-messages-include="demos/form/error.html" ng-show="myform.myname.$touched">
  </div>
</div>

<span ng-message="required">必填</span>
<span ng-message="char">非法字符</span>
<span ng-message="exist">名称已存在</span>
<span ng-message="minlength">太短了</span>

app.directive('namecheck', namecheck);

namecheck.$inject = ['httpservice', '$q'];

function namecheck(httpservice, $q){

  var name_reg = /^[a-za-z\u4e00-\u9fa5]+$/;

  return {
    restrict: 'a',
    require: 'ngmodel',
    link:function($scope,element,attrs,ctrl){

      ctrl.$validators.char = function(modelvalue, viewvalue) {
        var value = modelvalue || viewvalue;
        if(!name_reg.test(value)){
          return false;
        }
        return true;
      };
      ctrl.$asyncvalidators.exist = function(modelvalue, viewvalue){
        var value = modelvalue || viewvalue;
        var deferred = $q.defer();
        httpservice.get('api/users/' + value).then(function(res) {
          if(res.isexist){
            deferred.reject(false);

          }
          deferred.resolve(true);
        })

        return deferred.promise;
      }
    }
  }
}