My JSF Books/Videos My JSF Tutorials OmniFaces/JSF PPTs
JSF 2.3 Tutorial
JSF Caching Tutorial
JSF Navigation Tutorial
JSF Scopes Tutorial
JSF Page Author Beginner's Guide
OmniFaces 2.3 Tutorial Examples
OmniFaces 2.2 Tutorial Examples
JSF Events Tutorial
OmniFaces Callbacks Usages
JSF State Tutorial
JSF and Design Patterns
JSF 2.3 New Features (2.3-m04)
Introduction to OmniFaces
25+ Reasons to use OmniFaces in JSF
OmniFaces Validators
OmniFaces Converters
JSF Design Patterns
Mastering OmniFaces
Reusable and less-verbose JSF code

My JSF Resources ...

Java EE Guardian
Member of JCG Program
Member MVB DZone
Blog curated on ZEEF
OmniFaces is an utility library for JSF, including PrimeFaces, RichFaces, ICEfaces ...

[OmniFaces Utilities] - Find the right JSF OmniFaces 2 utilities methods/functions

Search on blog

Petition by Java EE Guardians

Twitter

sâmbătă, 12 decembrie 2015

[OmniFaces utilities 2.3] Get the typed Object value of the given tag attribute


[OmniFaces utilities] The getObject() returns the typed Object value of the given tag attribute.

Method:
Usage:

Suppose that we have a custom tag as below (is not important what it does; important is to notice that it supports an attribute of type String (named text), one of type boolean (named uppercase) and one that can be an Object (named repeat)):

<mt:textrepeat text="Vamos Rafa!" uppercase="true" repeat="5 step 3"/>

Now, if we write a custom tag handler for this custom tag, we can use the OmniFaces Facelets utility methods to access the values of the above attributes. For typed-Objects we will use Facelets#getObject()  that returns the typed Object value of the given tag attribute, and for simple Objects, we will use the Facelets#getObject() that returns the Object value of the given tag attribute:

import org.omnifaces.util.Facelets;
...
protected final TagAttribute text;
protected final TagAttribute repeat;
protected final TagAttribute uppercase;

public TextRepeatTagHandler(TagConfig config) {
 super(config);
 this.text = this.getRequiredAttribute("text");                     
 this.repeat = this.getRequiredAttribute("repeat");
 this.uppercase = this.getAttribute("uppercase");
}

@Override
public void apply(FaceletContext ctx, UIComponent parent) throws IOException {
       
 String textValue = Facelets.getObject(ctx, text, String.class);       
 boolean uppercaseValue = Facelets.getObject(ctx, uppercase, Boolean.class);
 Object repeat = Facelets.getObject(repeat, ctx);
 // ... do something with these values if they are not null
}
...

Niciun comentariu :

Trimiteți un comentariu

JSF BOOKS COLLECTION

Postări populare

Follow by Email

Visitors Starting 4 September 2015

Locations of Site Visitors