ajax – 如何在视图页面上显示服务器端验证错误

因为我正在使用grails框架而不使用controller.My应用程序是“单页应用程序”.我不想重新加载我的页面所以我已经编写了服务,即使用Ajax调用的RegistrationService.所以我使用knockout进行数据绑定.使用的数据库是 postgresql.
我有一个视图页面,我有一个电子邮件字段.当我输入一个重复的电子邮件ID并单击保存按钮然后我可以看到验证错误,即“电子邮件已被采取”但即使我正在写一个唯一的ID,那么我也得到相同的验证错误.这是因为它在modalModal.js页面中出错了,所以我没有得到如何解决这个问题.我只想在输入唯一ID并单击“保存”按钮时,不应该给出验证错误.

_newCostingpage.gsp  (my view page)

    <div id="light" class="white_content" style="color: black;">
    <form action="#/cart" method="post">
    <input type="hidden" name="url" value="${grailsApplication.config.serverURL}"/>
    <p><label>first name:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <input name="firstName"
             class="formElement" data-bind='value: firstName'/></label></p>
    <p><label>last name:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <input name="lastName" 
              class="formElement" data-bind='value: lastName' /></label></p>
    <p><label>organisation: <input name="organisation" class="formElement" data-
              bind='value: organisation' /></label></p>
<p><label>email:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
      <input name="email" class="formElement" data-bind='value: email' /></label><label 
         id="errorDiv"></label></p>
<p><label>password:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <input type="password" name="password"
         class="formElement" data-bind='value: password' /></label></p>
 <p><label style="margin-left: -37px;">confirm password:</label> <input
        type="password" name="confirmPassword" class="formElement" data-bind='value:
        confirmPassword' /></p>
 <p><input type="submit" value="register"/></p>
</form>
 <a href="javascript:void(0)"onclick="document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none';clearBox();">Close</a>
        </div>
        <div id="fade" class="black_overlay"></div>
    </div>

Domain class :-

  class Registration {
String firstName
String lastName
String organization
String email
String password
String confirmPassword

static constraints = {
    firstName(nullable:false)
    lastName(nullable:true)
    organization(blank:false)
    email(nullable:false,email:true,unique:true)
    password(blank:false)
    confirmPassword(blank:false)
               }
            }

modalModal.js

var ratPack = $.sammy(function() {
this.post('#/cart',function() {
    var firstname = this.params['firstName'];
    var lastName = this.params['lastName'];
    var organisation = this.params['organisation'];
    var email = this.params['email'];
    var password = this.params['password'];
    var confirmPassword = this.params['confirmPassword'];
    var baseurl = this.params['url'];
    $.ajax({
        type : 'POST',url :'http://localhost:9191/guido-rest-
                          resource/api/registration/'+firstname+'/'+lastName+'/'+email,success : function() {
            alert("success:");
        },error:function(){
           $('#errorDiv').text("Email has already been taken");
        }
    });
    });
      });
        $(function() {
       ratPack.run();
        });
        function clearBox(){
       $('.formElement').val("");
       }


   RegistrationResource.groovy

         package common.rest.resourcepl
         import static org.grails.jaxrs.response.Responses.*
         import javax.ws.rs.Consumes
         import javax.ws.rs.GET
         import javax.ws.rs.Produces
         import javax.ws.rs.Path
       import javax.ws.rs.PathParam
       import javax.ws.rs.POST
      import javax.ws.rs.core.Response
      import common.servicepl.RegistrationService
     @Path('/api/registration')
       class RegistrationResource {
   @GET
   @Produces('text/plain')
   String getRegistrationRepresentation() {
    'Registration'
    }
   def registrationService;
    @POST
    @Path('/{firstname}/{lastName}/{email}')
    Response create(@PathParam('firstname') String firstname,@PathParam('lastName') String lastName,@PathParam('email') String email) {
                return  
        RegistrationService().createRegistration(firstname,lastName,email);
  }
     }

     RegistrationService.groovy

         package common.servicepl
         import common.persistencepl.Registration
         class RegistrationService {
              def createRegistration(String firstName,String lastName,String email) {
        println "Inside Registration Service"
        def reg = new Registration();
        reg.firstName = firstName;
        reg.lastName = lastName;
        reg.password = "asdf";
        reg.confirmPassword = "asdf";
        reg.email = email;
        reg.organization = "fasdf";
        if(reg.save([flush:true])){
           return true
        }
        else
        {
          return false
        }
          }
         }