如何在JSF中设置HtmlOutputTag的值? [英] How do I set the value of HtmlOutputTag in JSF?
问题描述
我想在我的bean中动态创建控件。我正在使用JSF 2.0
I want to dynamically create controls in my bean. I am using JSF 2.0
HtmlOutputTag objHtmlOutputTag = new HtmlOutputTag();
我应该设置 HtmlOutputTag
的哪个属性设置 HtmlOutputTag的内容
?
Now which property of HtmlOutputTag
should I set to set the content of HtmlOutputTag
?
推荐答案
HtmlOutputTag
表示标签,而不是组件。而是使用 HtmlOutputText
。然后,您可以设置值
属性,就像在JSF页面中的实际组件中一样。如果您需要它是 ValueExpression
而不是原始值
,那么您需要使用 ExpressionFactory #createValueExpression()
。这是一个启动示例:
The HtmlOutputTag
represents a tag, not a component. Rather use HtmlOutputText
. Then, you can just set the value
property, exactly as you would do in a real component in the JSF page. If you need it to be a ValueExpression
rather than a raw value
, then you need to create it using ExpressionFactory#createValueExpression()
. Here's a kickoff example:
HtmlOutputText text = new HtmlOutputText();
text.setValueExpression("value", createValueExpression("#{bean.property}", String.class));
其中方便方法 createValueExpression()
这里看起来像:
where the convenience method createValueExpression()
here look like:
private static ValueExpression createValueExpression(String valueExpression, Class<?> valueType) {
FacesContext context = FacesContext.getCurrentInstance();
return context.getApplication().getExpressionFactory()
.createValueExpression(context.getELContext(), valueExpression, valueType);
}
在一些实用程序类中远远隐藏它,这样你就不需要一遍又一遍地重复所有代码;) valueType
参数显然应该代表该属性的实际类型。
hide it far away in some utility class so that you don't need to repeat all that code again and again ;) The valueType
argument obviously should represent the actual type of the property.
JSF页面中的最终结果应如下所示:
The final result in the JSF page should then look like this:
<h:outputText value="#{bean.property}" />
这就是说,根据功能要求,可能确实有更好更清洁的方法来解决问题需求。如果你愿意,你可以详细说明一下,以便我们可以在必要时提出更好的方法。
That said, depending on the functional requirement, there may indeed be better and cleaner ways to solve the functional requirement. If you want, you can elaborate a bit more about it so that we can if necessary suggest better ways.
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