/*
* [The "BSD licence"]
* Copyright (c) 2013-2014 Dandelion
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Dandelion nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.github.dandelion.core.asset.locator.spi;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import com.github.dandelion.core.Context;
import com.github.dandelion.core.DandelionException;
import com.github.dandelion.core.asset.Asset;
import com.github.dandelion.core.asset.processor.spi.AssetProcessor;
import com.github.dandelion.core.storage.AssetStorageUnit;
import com.github.dandelion.core.utils.StringUtils;
import com.github.dandelion.core.web.AssetRequestContext;
/**
* <p>
* Abstract base class for all {@link AssetLocator}.
*
* <p>
* By default, all {@link AssetLocator} are active and caching of assets is not
* forced. It's up to the implementation to adapt this behaviour.
*
* @author Thibault Duchateau
* @since 0.10.0
*/
public abstract class AbstractAssetLocator implements AssetLocator {
protected boolean active = true;
protected Context context;
/**
* {@inheritDoc}
*/
@Override
public boolean isActive() {
return active;
}
/**
* {@inheritDoc}
*/
@Override
public boolean isCachingForced() {
return false;
}
/**
* {@inheritDoc}
*/
@Override
public void initLocator(Context context) {
this.context = context;
}
/**
* <p>
* Checks that the asset if properly configured before computing its
* location.
*
* @param AssetStorageUnit
* The asset storage unit from which the location should be
* extracted.
* @param request
* The current HTTP request.
* @throws DandelionException
* if the location associated with the selected location key is
* null or empty.
*/
@Override
public String getLocation(AssetStorageUnit asu, HttpServletRequest request) {
String location = asu.getLocations().get(getLocationKey());
if (StringUtils.isBlank(location)) {
StringBuilder sb = new StringBuilder("The asset ");
sb.append(asu.toLog());
sb.append(" configured with a '");
sb.append(getLocationKey());
sb.append("' location key has a blank location. Please correct this location in the corresponding JSON file.");
throw new DandelionException(sb.toString());
}
return doGetLocation(asu, request);
}
public abstract String doGetLocation(AssetStorageUnit asu, HttpServletRequest request);
/**
* <p>
* Returns the content of the given {@link AssetStorageUnit}, using the
* location returned by
* {@link #getLocation(AssetStorageUnit, HttpServletRequest)}.
*
* <p>
* The content is processed with variables of the
* {@link AssetRequestContext} if there is some, before being returned.
*
* @param asu
* The asset storage unit from which the content should be
* extracted.
* @param request
* The current HTTP request.
* @return the content of location
*/
@Override
public String getContent(AssetStorageUnit asu, HttpServletRequest request) {
String location = getLocation(asu, request);
Map<String, Object> parameters = AssetRequestContext.get(request).getParameters(asu.getName());
String content = doGetContent(location, parameters, request);
// Apply variable replacement
if (!parameters.isEmpty()) {
for (Map.Entry<String, Object> entry : parameters.entrySet()) {
content = content.replace(entry.getKey(), entry.getValue().toString());
}
}
return content;
}
/**
* <p>
* Returns the content of the given {@link Asset}, using its
* {@link Asset#getFinalLocation()} value.
*
* <p>
* Note that this method can be used to access the asset's content after the
* {@link AssetProcessor}'s execution.
*
* @param asset
* The asset from which the content should be extracted.
* @param request
* The current HTTP request.
* @return the raw content (unprocessed) of the passed {@link Asset}.
*/
public String getContent(Asset asset, HttpServletRequest request) {
Map<String, Object> parameters = AssetRequestContext.get(request).getParameters(asset.getName());
String content = doGetContent(asset.getFinalLocation(), parameters, request);
// Apply variable replacement
if (!parameters.isEmpty()) {
for (Map.Entry<String, Object> entry : parameters.entrySet()) {
content = content.replace(entry.getKey(), entry.getValue().toString());
}
}
return content;
}
protected abstract String doGetContent(String location, Map<String, Object> parameters, HttpServletRequest request);
}