StringTemplate为给定模板定义的属性列表 [英] StringTemplate list of attributes defined for a given template

问题描述

我开始使用StringTemplate 4，我正在尝试从存储在数据库中的简单字符串创建模板。我使用这样的东西：

I am getting started with StringTemplate 4 and I am trying to create a template from a simple string stored in a database. I use something like this:

STGroup group = new STGroupString(null, someTemplateString, '$', '$');
ST st = group.getInstanceOf(someTemplateName);
st.add(someAttribute, someValue);

如果定义全部或少于为模板定义的属性<$ c $，现在一切正常C> someTemplateName 。现在如果我尝试添加一个不存在的属性，我会得到以下异常：

Now everything works fine if I define all or less than the attribute defined for the template someTemplateName. Now if I try to add an attribute that doesn't exist, I get the following exception:

no such attribute: fake
java.lang.IllegalArgumentException: no such attribute: fake
  ...

这是有道理的。但是，似乎我无法事先知道为模板 someTemplateName 定义了哪些属性。我期待找到类似的东西：

which makes sense. However, it seems like there's no way for me to know beforehand which attributes are defined for the template someTemplateName. I was expecting to find something like:

bool isDef = st.isDefined(someAttribute);

但是没有这样的方法。我对么？有什么方法吗？

but there's no such method. Am I correct? Is there any way around this?

推荐答案

你可以用 st.impl.formalArguments 访问 Map< String，FormalArgument> 定义参数的位置。请注意，对于某些模板，此字段将为 null 。

You can use st.impl.formalArguments to access the Map<String, FormalArgument> where the arguments are defined. Note that for some templates this field will be null.

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