How do I set the value of HtmlOutputTag in JSF?
I want to dynamically create controls in my bean. I am using JSF 2.0
Ht开发者_如何学PythonmlOutputTag objHtmlOutputTag = new HtmlOutputTag();
Now which property of HtmlOutputTag
should I set to set the content of HtmlOutputTag
?
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));
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);
}
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.
The final result in the JSF page should then look like this:
<h:outputText value="#{bean.property}" />
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.
As usual, my advice would be to not add/remove component dynamically. Solve your problem another way:
- Toggle visibility of components
- Rebind the data belonging to a component
Adding/removing component dynamically is always a source of trouble and chances are that you can do it another way much simpler.
The outputText
component is easy to use:
<h:outputText value="#{BackingBean.myProperty}"/>
And you define a getter/setter for myProperty
in your backing bean. If you really want to do it programmatically (which I discourage unless you have strong arguments), here is an example with a dynamic table.
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