org.apache.wicket.request.mapper.AbstractMapper Maven / Gradle / Ivy
/*
* 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.
*/
package org.apache.wicket.request.mapper;
import java.util.List;
import org.apache.wicket.request.IRequestMapper;
import org.apache.wicket.request.Request;
import org.apache.wicket.request.Url;
import org.apache.wicket.request.Url.QueryParameter;
import org.apache.wicket.request.mapper.parameter.IPageParametersEncoder;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.string.Strings;
/**
*
*/
public abstract class AbstractMapper implements IRequestMapper
{
/**
* If the string is in a placeholder format ${key} this method returns the key.
*
* @param s
* @return placeholder key or null if string is not in right format
*/
protected String getPlaceholder(final String s)
{
return getPlaceholder(s, '$');
}
/**
* If the string is in an optional parameter placeholder format #{key} this method returns the
* key.
*
* @param s
* @return placeholder key or null if string is not in right format
*/
protected String getOptionalPlaceholder(final String s)
{
return getPlaceholder(s, '#');
}
/**
* If the string is in a placeholder format x{key}, where 'x' can be specified, this method
* returns the key.
*
* @param s
* @param startChar
* the character used to indicate the start of the placeholder
* @return placeholder key or null if string is not in right format
*/
protected String getPlaceholder(final String s, char startChar)
{
if ((s == null) || (s.length() < 4) || !s.startsWith(startChar + "{") || !s.endsWith("}"))
{
return null;
}
else
{
return s.substring(2, s.length() - 1);
}
}
/**
* Construct.
*/
public AbstractMapper()
{
super();
}
/**
* Returns true if the given url starts with specified segments.
*
* @param url
* @param segments
* @return true if the URL starts with the specified segments, false
* otherwise
*/
protected boolean urlStartsWith(final Url url, final String... segments)
{
if (url == null)
{
return false;
}
List urlSegments = url.getSegments();
for (int i = 0; i < segments.length; ++i)
{
String segment = segments[i];
String urlSegment = safeSegmentGetter(urlSegments, i, null);
if (urlSegment == null && getOptionalPlaceholder(segment) == null)
{
// if the 'segment' has static value or is mandatory placeholder
return false;
}
else if (!segment.equals(urlSegment) &&
(getPlaceholder(segment) == null &&
getOptionalPlaceholder(segment) == null))
{
return false;
}
}
return true;
}
/**
* Utility method to safely get an element from a list of String.
* If the specified index is bigger than the size of the list
* the default value is returned.
*
* @param segments
* @param index
* @param defaultValue
* @return the element at the specified position or the default value if the list size is smaller.
*
*/
protected String safeSegmentGetter(List segments, int index, String defaultValue)
{
if (index < segments.size())
{
return segments.get(index);
}
return defaultValue;
}
/**
* Extracts {@link PageParameters} from the URL using the given {@link IPageParametersEncoder} .
*
* @param request
* @param segmentsToSkip
* how many URL segments should be skipped because they "belong" to the
* {@link IRequestMapper}
* @param encoder
* @return PageParameters instance
*/
protected PageParameters extractPageParameters(final Request request, int segmentsToSkip,
final IPageParametersEncoder encoder)
{
Args.notNull(request, "request");
Args.notNull(encoder, "encoder");
// strip the segments and first query parameter from URL
Url urlCopy = new Url(request.getUrl());
while ((segmentsToSkip > 0) && (urlCopy.getSegments().isEmpty() == false))
{
urlCopy.getSegments().remove(0);
--segmentsToSkip;
}
if (!urlCopy.getQueryParameters().isEmpty() &&
Strings.isEmpty(urlCopy.getQueryParameters().get(0).getValue()))
{
removeMetaParameter(urlCopy);
}
return encoder.decodePageParameters(urlCopy);
}
/**
* The new {@link IRequestMapper}s use the first query parameter to hold meta information about
* the request like page version, component version, locale, ... The actual
* {@link IRequestMapper} implementation can decide whether the this parameter should be removed
* before creating {@link PageParameters} from the current {@link Url#getQueryParameters() query
* parameters}
*
* @param urlCopy
* the {@link Url} that first query parameter has no value
*/
protected void removeMetaParameter(final Url urlCopy)
{
}
/**
* Encodes the given {@link PageParameters} to the URL using the given
* {@link IPageParametersEncoder}. The original URL object is unchanged.
*
* @param url
* @param pageParameters
* @param encoder
* @return URL with encoded parameters
*/
protected Url encodePageParameters(Url url, PageParameters pageParameters,
final IPageParametersEncoder encoder)
{
Args.notNull(url, "url");
Args.notNull(encoder, "encoder");
if (pageParameters == null)
{
pageParameters = new PageParameters();
}
Url parametersUrl = encoder.encodePageParameters(pageParameters);
if (parametersUrl != null)
{
// copy the url
url = new Url(url);
for (String s : parametersUrl.getSegments())
{
url.getSegments().add(s);
}
for (QueryParameter p : parametersUrl.getQueryParameters())
{
url.getQueryParameters().add(p);
}
}
return url;
}
/**
* Convenience method for representing mountPath as array of segments
*
* @param mountPath
* @return array of path segments
*/
protected String[] getMountSegments(String mountPath)
{
if (mountPath.charAt(0) == '/')
{
mountPath = mountPath.substring(1);
}
Url url = Url.parse(mountPath);
String[] res = new String[url.getSegments().size()];
for (int i = 0; i < res.length; ++i)
{
res[i] = url.getSegments().get(i);
}
return res;
}
}