Question

我正在使用Play 2.1 我使用辅助字段构造函数创建了一个选择下拉框。下拉框有3个字段，默认：“选择性别”，男性和女性。如何确保用户选择男性或女性，而不是默认值？（必填的下拉字段）

Answer 1

我正在使用 Play！Framework 2.1.0 ，下面是您问题的简单解决方案：

模型应该是这样的:(以下是您问题的简单模型）

package models;

import play.data.validation.Constraints;

public class Gender {
   // This field must have a value (not null or not an empty string)
   @Constraints.Required
   public String gender;
}

控制器应该是这样的：

/** Render form with select input **/
public static Result selectInput() {
   Form<Gender> genderForm = Form.form(Gender.class);

   return ok(views.html.validselect.render(genderForm));
}

/** Handle form submit **/
public static Result validateSelectInput() {
   Form<Gender> genderForm = Form.form(Gender.class).bindFromRequest();

   if (genderForm.hasErrors()) { // check validity
      return ok("Gender must be filled!"); // can be bad request or error, etc.
   } else {
      return ok("Input is valid"); // success validating input
   }
}

模板/视图应如下所示：

@(genderForm: Form[models.Gender])
@import views.html.helper._

@main(title = "Validate Select") {
   @form(action = routes.Application.validateSelectInput()) {
      @********** The default value for select input should be "" as a value *********@
      @select(
         field = genderForm("gender"),
         options = options("" -> "Select Gender", "M" -> "Male", "F" -> "Female")
      )

      <input type="submit" value="Post">
   }
}

另请参阅此帖子：Use of option helper in Play Framework 2.0 templates

播放框架选择输入验证

1 个答案: