如何输出< option selected =“true”>>来自JSPX？ [英] How to output <option selected="true"> from JSPX?

问题描述

几个html标签将给定属性的任意值解释为true - >选项标签让人想起。

我常常会这样做：

 < C：选择> 
< c：when test =$ {isSelected}/> 
< option selected =true> Opt1< / option> 
< / c：当> 
< c：otherwise /> 
< option> Opt1< / option> 
< / c：否则> 
   

我知道我可以声明一个自定义来封装这个行为，但 变得非常难看，除非我用java编写它。

有没有更聪明的方法来做到这一点？ 方法是使用自定义标签。

我喜欢JSP2X转换器采用的方法，在WEB-INF / tags文件夹中定义自定义标签让你做到这一点：

 < jspx：element name =option> 
< c：if test =$ {selected}> 
 < / c：if> 
< jspx：body> Opt1< / jspx：body> 
< / jspx：element> 
  

更紧凑的方法可能是创建一个自定义标签，专门用于做出正确选择的选项，为所选属性取一个布尔值，如果它是真的，则发出selected =selected属性，否则不会。这将会更紧凑一些：

 < jspx：option selected =$ {selected}> Opt1<选项> 
  

A few html tags interpret "any" value of a give attribute as "true" -> option tags come to mind.

I frequently end up doing something like this:

<c:choose>
   <c:when test="${isSelected}"/>
        <option selected="true">Opt1</option> 
    </c:when>
   <c:otherwise/>
        <option>Opt1</option> 
   </c:otherwise>
</c:choose>

I know I can declare a custom to encapslate this behaviour but that also gets pretty ugly, unless I code it in java.

Is there a smarter way to do this ?

解决方案

One way to approach this would be to use custom tag(s).

I like the approach that the JSP2X converter takes, defining custom tags in your WEB-INF/tags folder that let you do this:

<jspx:element name="option">
    <c:if test="${selected}">
        <jspx:attribute name="selected">selected</jspx:attribute>
    </c:if>
    <jspx:body>Opt1</jspx:body>
</jspx:element>

A more compact approach might be to create a custom tag specifically for an option that did the right thing, taking a boolean value for the selected attribute, emitting a selected="selected" attribute if it's true, not otherwise. This would be a bit more compact:

<jspx:option selected="${selected}">Opt1</option>

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