/*
 * Copyright 2005-2008 Les Hazlewood, Jeremy Haile
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jsecurity.web.tags;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

/**
 * @since 0.1
 * @author Les Hazlewood
 * @author Jeremy Haile
 */
public abstract class PermissionTag extends SecureTag {

    private String permission = null;

    public PermissionTag() {
    }

    public String getPermission() {
        return permission;
    }

    public void setPermission(String permission) {
        this.permission = permission;
    }

    protected void verifyAttributes() throws JspException {
        String permission = getPermission();

        if ( permission == null || permission.length() == 0 ) {
            String msg = "The 'permission' tag attribute must be set.";
            throw new JspException( msg );
        }
    }

    public int onDoStartTag() throws JspException {

        String p = getPermission();

        boolean show = showTagBody( p );
        if ( show ) {
            return TagSupport.EVAL_BODY_INCLUDE;
        } else {
            return TagSupport.SKIP_BODY;
        }
    }

    protected boolean isPermitted( String p ) {
        return getSubject() != null && getSubject().isPermitted( p );
    }

    protected abstract boolean showTagBody( String p );

}