package org.apache.commons.digester3.plugins.strategies;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.io.InputStream;
import java.util.Properties;

import org.apache.commons.digester3.Digester;
import org.apache.commons.digester3.plugins.PluginException;
import org.apache.commons.digester3.plugins.RuleFinder;
import org.apache.commons.digester3.plugins.RuleLoader;

A rule-finding algorithm which looks for a resource file in the classpath whose name is derived from the plugin class
name plus a specified suffix.

If the resource-file is found, then it is expected to define a set of Digester rules in xmlrules format.
Since:
1.6/**
 * A rule-finding algorithm which looks for a resource file in the classpath whose name is derived from the plugin class
 * name plus a specified suffix.
 * <p>
 * If the resource-file is found, then it is expected to define a set of Digester rules in xmlrules format.
 * 
 * @since 1.6
 */
public class FinderFromDfltResource
    extends RuleFinder
{

    private static final String DFLT_RESOURCE_SUFFIX = "RuleInfo.xml";

    private final String resourceSuffix;

    
See findLoader. /** See {@link #findLoader}. */
    public FinderFromDfltResource()
    {
        this( DFLT_RESOURCE_SUFFIX );
    }

    
Create a rule-finder which can load an xmlrules file, cache the rules away, and later add them as a plugin's
custom rules when that plugin is referenced.
Params:
resourceSuffix – must be non-null./**
     * Create a rule-finder which can load an xmlrules file, cache the rules away, and later add them as a plugin's
     * custom rules when that plugin is referenced.
     * 
     * @param resourceSuffix must be non-null.
     */
    public FinderFromDfltResource( String resourceSuffix )
    {
        this.resourceSuffix = resourceSuffix;
    }

    
If there exists a resource file whose name is equal to the plugin class name + the suffix specified in the
constructor, then load that file, run it through the xmlrules module and return an object encapsulating those
rules.

If there is no such resource file, then just return null.

The returned object (when non-null) will add the selected rules to the digester whenever its addRules method is
invoked.
Params:
d – The digester instance where locating plugin classes
pluginClass – The plugin Java class
p – The properties object that holds any xml attributes the user may have specified on the plugin
         declaration in order to indicate how to locate the plugin rules.
Throws:
PluginException – if the algorithm finds a source of rules, but there is something invalid
        about that source.
Returns:
a source of digester rules for the specified plugin class./**
     * If there exists a resource file whose name is equal to the plugin class name + the suffix specified in the
     * constructor, then load that file, run it through the xmlrules module and return an object encapsulating those
     * rules.
     * <p>
     * If there is no such resource file, then just return null.
     * <p>
     * The returned object (when non-null) will add the selected rules to the digester whenever its addRules method is
     * invoked.
     *
     * @param d The digester instance where locating plugin classes
     * @param pluginClass The plugin Java class
     * @param p The properties object that holds any xml attributes the user may have specified on the plugin
     *          declaration in order to indicate how to locate the plugin rules.
     * @return a source of digester rules for the specified plugin class.
     * @throws PluginException if the algorithm finds a source of rules, but there is something invalid
     *         about that source.
     */
    @Override
    public RuleLoader findLoader( Digester d, Class<?> pluginClass, Properties p )
        throws PluginException
    {

        String resourceName = pluginClass.getName().replace( '.', '/' ) + resourceSuffix;

        InputStream is = pluginClass.getClassLoader().getResourceAsStream( resourceName );

        if ( is == null )
        {
            // ok, no such resource
            return null;
        }

        return FinderFromResource.loadRules( d, pluginClass, is, resourceName );
    }

}