CODEWITHSUNDEEP
jsf
amphibient
amphibient

Reputation: 31248

How to get UIComponent value in Java?

I have a method in my JSF controller that is invoked by an ajax tag nested inside a visual component (really irrelevant which one). The method takes a single argument of type AjaxBehaviorEvent, from which I can obtain a Java representation of the invoking HTML visual component as a UIComponent and also downcast it to its specific corresponding type (e.g. h:inputText corresponding to HtmlInputText).

I understand that, in most cases, the value of the HTML visual component would be retrieved easily by referencing either the controller or entity [g|s]etters to which the form fields are mapped in the view. However, in my particular case, I would like to fetch the value of the visual component (in my case a form field) through its Java object rendering. While studying the faces API, I found ways to read various properties of the object, such as the ID or context but not the value that the component currently holds in the view.

Can anybody explain whether I am just not finding the right way to read it or it is so by design? If the latter, can you explain why it is designed like that? Is it to disable "backdoor" access to form fields as opposed to going through the view mapping?

Upvotes: 4

Views: 8326

Answers (1)

kolossus
kolossus

Reputation: 20691

There are a multitude of ways to pull values off a component. Going by what you already have UIInputt#getValue() and UIInput#getSubmittedValue() will provide the value.

The UIInput#getSubmittedValue() is fit for the purpose only between the APPLY_REQUEST_VALUES and VALIDATE phases of the JSF request. All other phases after, use the UIInputt#getValue(). You'll be using UIInput instead of the raw UIComponent you pulled from the event (UIInput extends UIComponent and it's the parent class for all input components that accept user-edited values). What you'll have will eventually look like:

     UIInput theInput = (UIInput)event.getSource();
     Object theValue = theInput.getValue();

There are other ways (not as clean) to get values within the request lifecycle also

Upvotes: 7

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