UserTagHandler.java

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package com.sun.faces.facelets.tag;

import com.sun.faces.facelets.FaceletContextImplBase;
import com.sun.faces.facelets.TemplateClient;
import com.sun.faces.facelets.el.VariableMapperWrapper;
import com.sun.faces.facelets.tag.ui.DefineHandler;

import javax.el.VariableMapper;
import javax.faces.component.UIComponent;
import javax.faces.view.facelets.FaceletContext;
import javax.faces.view.facelets.TagAttribute;
import javax.faces.view.facelets.TagConfig;
import javax.faces.view.facelets.TagException;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

/**
 * A Tag that is specified in a FaceletFile. Takes all attributes specified and
 * sets them on the FaceletContext before including the targeted Facelet file.
 * 
 * @author Jacob Hookom
 * @version $Id$
 */
final class UserTagHandler extends TagHandlerImpl implements TemplateClient {

    protected final TagAttribute[] vars;

    protected final URL location;

    protected final Map handlers;

    /**
     * @param config
     */
    public UserTagHandler(TagConfig config, URL location) {
        super(config);
        this.vars = this.tag.getAttributes().getAll();
        this.location = location;
                Iterator itr = this.findNextByType(DefineHandler.class);
        if (itr.hasNext()) {
            handlers = new HashMap();

            DefineHandler d = null;
            while (itr.hasNext()) {
                d = (DefineHandler) itr.next();
                this.handlers.put(d.getName(), d);
            }
        } else {
            handlers = null;
        }
    }

    /**
     * Iterate over all TagAttributes and set them on the FaceletContext's
     * VariableMapper, then include the target Facelet. Finally, replace the old
     * VariableMapper.
     * 
     * @see TagAttribute#getValueExpression(FaceletContext, Class)
     * @see VariableMapper
     * @see javax.faces.view.facelets.FaceletHandler#apply(javax.faces.view.facelets.FaceletContext, javax.faces.component.UIComponent)
     */
    @Override
    public void apply(FaceletContext ctxObj, UIComponent parent)
    throws IOException {
        FaceletContextImplBase ctx = (FaceletContextImplBase) ctxObj;
        VariableMapper orig = ctx.getVariableMapper();
        
        // setup a variable map
        if (this.vars.length > 0) {
            VariableMapper varMapper = new VariableMapperWrapper(orig);
            for (int i = 0; i < this.vars.length; i++) {
                varMapper.setVariable(this.vars[i].getLocalName(), this.vars[i]
                        .getValueExpression(ctx, Object.class));
            }
            ctx.setVariableMapper(varMapper);
        }
        
        // eval include
        try {
            ctx.pushClient(this);
            ctx.includeFacelet(parent, this.location);
        } catch (FileNotFoundException e) {
            throw new TagException(this.tag, e.getMessage());
        } finally {
            
            // make sure we undo our changes
            ctx.popClient(this);
            ctx.setVariableMapper(orig);
        }
    }

    @Override
    public boolean apply(FaceletContext ctx, UIComponent parent, String name)
    throws IOException {
        if (name != null) {
            if (this.handlers == null) {
                return false;
            }
            DefineHandler handler = (DefineHandler) this.handlers.get(name);
            if (handler != null) {
                handler.applyDefinition(ctx, parent);
                return true;
            } else {
                return false;
            }
        } else {
             this.nextHandler.apply(ctx, parent);
             return true;
         }
    }

}