在Play Framework 2上将表单请求与ManyToOne字段绑定 [英] Binding form request with ManyToOne field on play framework 2

问题描述

当我将多音域添加到我的模型"Item"中时，会出现此错误&我尝试绑定相应的表格.

I get this error when i add a manytoone field to my Model "Item" & i try to bind the corresponding form.

Execution exception
[IllegalStateException: No value] at line 31

=> Item item = itemForm.bindFromRequest().get();

项目" 模型: 封装模型；

the "Item" Model: package models;

@Entity 
public class Item extends Model {

    @Id
    public Long id;

    @ManyToOne
    @Constraints.Required
    @Formats.NonEmpty
    public Category category;

    @Constraints.Required
    public String title;

    @Constraints.Required
    public String content;

    public String picture;

    (..)    
}

查看表格:

    @helper.form(action = routes.Application.newItem(), 'id -> "item_form", 'method -> "POST", 'enctype -> "multipart/form-data"){
    <fieldset>
        @helper.inputText(
        itemForm("title"),
        '_label -> "Titre"  )

        @helper.select(
        itemForm("category"), 
        helper.options(Category.list),
        '_label -> "Categorie")

        @helper.textarea(
        itemForm("content"),
        '_label -> "Description")

         @helper.inputFile(
         field = itemForm("picture"), 
         '_display -> "Attachment", 
         '_label -> Messages("Image") )
         <input type="submit" value="Ajouter">

    </fieldset>
    }

控制器:

public static Result newItem(){
        Item item = itemForm.bindFromRequest().get(); //SOMETHING GO WRONG HERE
        MultipartFormData body = request().body().asMultipartFormData();
        FilePart picture = body.getFile("picture");  
        if (picture != null) {
              (...)
        }
            else{
              (...)
            }
}

推荐答案

考虑到类别模型具有id字段，类别字段的表单视图应该是.

The form view for category field should be, considering Category model has id field.

@helper.select(
        itemForm("category.id"), 
        helper.options(Category.list),
        '_label -> "Categorie")

这篇关于在Play Framework 2上将表单请求与ManyToOne字段绑定的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！