Freemarker - 检查布尔值

Question

检查 FreeMarker 中表单数据中 boolean 值是否正确的语法是什么，我的代码：

<#if "${form.allStores}" !false>
        <@displayRow label="Receiving Stores" value="All Stores" />
    <#elseif "${form.storesReceiving}" == false || "${form.storesReceiving}"?has_content>
        <@displayRow label="Receiving Stores" value="No Stores"/>
    <#else>

我收到此错误：

Could not prepare mail; nested exception is freemarker.core._MiscTemplateException: Can't convert boolean to string automatically, because the "boolean_format" setting was "true,false", which is the legacy default computer-language format, and hence isn't accepted. --

Answer 1

Freemarker的有那么函数自2.3.23版本：

<@displayRow label="Receiving Stores" value="${form.allStores?then('All Stores', 'No Stores')}"/>

像 booleanExp?then(whenTrue, whenFalse) 一样使用

也类似于java，你可以使用!运算符来否定：

<#if !form.allStores> 
    <@displayRow label="Receiving Stores" value="No Stores"/>

然后布尔值只能是真/假所以不需要elseif：

<#else>
    <@displayRow label="Receiving Stores" value="All Stores" />
</#if>

称为逻辑非运算符。用于反转其操作数的逻辑状态。如果条件为真，则逻辑非运算符将变为假。

也更喜欢使用第一个正条件作为：

<#if form.allStores> 
    <@displayRow label="Receiving Stores" value="All Stores" />
<#else>
    <@displayRow label="Receiving Stores" value="No Stores"/>
</#if>