Question

我试图在点击按钮时添加输入字段，我收到如下异常：.IllegalStateException: Neither BindingResult nor plain target object for bean name 'name' available as request attribute
我假设它正在这样做，因为它不能保证有一个对象将结果绑定到提交？有没有办法解决？或者我不可能动态加载字段？

这是我的HTML，我现在只是在玩这个概念所以它是最低限度的

<input type="button" id="more_ingredients" onclick="add_ingredients();" value="add more">
<form:form commandName="newIngredients" id="form">
   <div id="wrapper">
      <form:input path="name"/>
      <form:input path="amount"/>
      <form:input path="unit"/>
      <br>
      <form:input path="name"/>
      <form:input path="amount"/>
      <form:input path="unit"/>
      <br>
   </div>   
   <form:button type="submit">Submit</form:button>
</form:form>

这是我的JS

function add_ingredients() {
   document.getElementById('form').innerHTML += '<form:input path="name /> <form:input path="amount"/> <form:input path="unit"/>';
   //The exception is being triggered by the above line, if I remove the 'form:' tag, the error will disappear.  
}

我可以动态输入标准输入字段，但是我无法为控制器分配路径。

修改

如果我用声明的目标对象包装a，那么错误就会消失：

<form:form commandName="newIngredients"> <form:input path="name" /> <form:input path="amount"/> <form:input path="unit"/></form:form>

这会消除错误，但自动生成的输入内的输入不会传递给控制器。

Answer 1

我使用.clone（）方法解决了这个问题，使用我发现here 的代码片段我通过简单地更改被克隆的html来略微调整它以支持spring form标签。

HTML：

<form:form commandName="newIngredients">
    <div id="dynamic_ingredients">
        <a id="add-ingredient" href="#">Add Another Ingredient +</a>
        <div class="ingredient_field">
            <form:input path="name"/>
            <form:input path="amount"/>
            <form:input path="unit"/>
        </div>
    </div>
</form:form>

jQuery：

$(document).ready(function(){
    //the click function does not seem to be working in the example, so I have replaced it with this.
    $(document).on('click', '.icon-delete', function(){
        $(this).parent().remove();
    });
    //Keep a single clone of the original
    var clonedField = $('.ingredient_field').clone(), 
    main = $('#dynamic_ingredients');

    // Add in the delete <a>
    $('<a>', {
        text: 'Remove Step', 
        class: 'icon-delete', 
        href: '#'
    }).appendTo(clonedField);

    // Clone the cloned original and append it back to the list
    $('#add-ingredient').click(function() {
        main.append(clonedField.clone());
        return false;
    });
});

从按钮单击事件 - Spring MVC动态加载<form：input>

1 个答案: