MasterDetail.java

/*
 * Copyright 2011 PrimeFaces Extensions.
 *
 * 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.
 *
 * $Id: MasterDetail.java 555 2011-12-08 20:52:00Z Zoigln@googlemail.com $
 */

package org.primefaces.extensions.component.masterdetail;

import java.lang.reflect.Array;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.el.MethodExpression;
import javax.el.ValueExpression;
import javax.faces.FacesException;
import javax.faces.application.ResourceDependency;
import javax.faces.component.UIComponent;
import javax.faces.component.UIComponentBase;
import javax.faces.context.FacesContext;
import javax.faces.context.PartialViewContext;
import javax.faces.event.AbortProcessingException;
import javax.faces.event.ComponentSystemEvent;
import javax.faces.event.ListenerFor;
import javax.faces.event.PostRestoreStateEvent;

import org.apache.commons.lang.StringUtils;
import org.primefaces.util.Constants;

/**
 * <code>MasterDetail</code> component.
 *
 * @author  Oleg Varaksin / last modified by $Author: Zoigln@googlemail.com $
 * @version $Revision: 555 $
 */
@ListenerFor(systemEventClass = PostRestoreStateEvent.class)
@ResourceDependency(library = "primefaces-extensions", name = "primefaces-extensions.css")
public class MasterDetail extends UIComponentBase {

	public static final String COMPONENT_FAMILY = "org.primefaces.extensions.component";
	private static final String DEFAULT_RENDERER = "org.primefaces.extensions.component.MasterDetailRenderer";
	private static final String OPTIMIZED_PACKAGE = "org.primefaces.extensions.component.";

	public static final String CONTEXT_VALUE_VALUE_EXPRESSION = "mdContextValueVE";
	public static final String SELECTED_LEVEL_VALUE_EXPRESSION = "selectedLevelVE";
	public static final String SELECTED_STEP_VALUE_EXPRESSION = "selectedStepVE";
	public static final String CONTEXT_VALUES = "mdContextValues";
	public static final String SKIP_PROCESSING = "mdSkipProcessing";
	public static final String SELECT_DETAIL_REQUEST = "_selectDetailRequest";
	public static final String CURRENT_LEVEL = "_currentLevel";
	public static final String SELECTED_LEVEL = "_selectedLevel";
	public static final String SELECTED_STEP = "_selectedStep";
	public static final String CURRENT_CONTEXT_VALUE = "_curContextValue";
	public static final String SKIP_PROCESSING_REQUEST = "_skipProcessing";

	private MasterDetailLevel detailLevelToProcess;
	private MasterDetailLevel detailLevelToGo;
	private int levelPositionToProcess = -1;
	private int levelCount = -1;

	/**
	 * Properties that are tracked by state saving.
	 *
	 * @author  Oleg Varaksin / last modified by $Author: Zoigln@googlemail.com $
	 * @version $Revision: 555 $
	 */
	protected enum PropertyKeys {

		level,
		flow,
		flowListener,
		showBreadcrumb,
		style,
		styleClass;

		private String toString;

		PropertyKeys(final String toString) {
			this.toString = toString;
		}

		PropertyKeys() {
		}

		@Override
		public String toString() {
			return ((this.toString != null) ? this.toString : super.toString());
		}
	}

	public MasterDetail() {
		setRendererType(DEFAULT_RENDERER);
	}

	@Override
	public String getFamily() {
		return COMPONENT_FAMILY;
	}

	public int getLevel() {
		return (Integer) getStateHelper().eval(PropertyKeys.level, 1);
	}

	public void setLevel(final int level) {
		setAttribute(PropertyKeys.level, level);
	}

	public Object getFlow() {
		return getStateHelper().eval(PropertyKeys.flow, null);
	}

	public void setFlow(final Object flow) {
		setAttribute(PropertyKeys.flow, flow);
	}

	public MethodExpression getFlowListener() {
		return (MethodExpression) getStateHelper().eval(PropertyKeys.flowListener, null);
	}

	public void setFlowListener(final MethodExpression flowListener) {
		setAttribute(PropertyKeys.flowListener, flowListener);
	}

	public boolean isShowBreadcrumb() {
		return (Boolean) getStateHelper().eval(PropertyKeys.showBreadcrumb, true);
	}

	public void setShowBreadcrumb(final boolean showBreadcrumb) {
		setAttribute(PropertyKeys.showBreadcrumb, showBreadcrumb);
	}

	public String getStyle() {
		return (String) getStateHelper().eval(PropertyKeys.style, null);
	}

	public void setStyle(final String style) {
		setAttribute(PropertyKeys.style, style);
	}

	public String getStyleClass() {
		return (String) getStateHelper().eval(PropertyKeys.styleClass, null);
	}

	public void setStyleClass(final String styleClass) {
		setAttribute(PropertyKeys.styleClass, styleClass);
	}

	public void setAttribute(final PropertyKeys property, final Object value) {
		getStateHelper().put(property, value);

		@SuppressWarnings("unchecked")
		List<String> setAttributes =
		    (List<String>) this.getAttributes().get("javax.faces.component.UIComponentBase.attributesThatAreSet");
		if (setAttributes == null) {
			final String cname = this.getClass().getName();
			if (cname != null && cname.startsWith(OPTIMIZED_PACKAGE)) {
				setAttributes = new ArrayList<String>(6);
				this.getAttributes().put("javax.faces.component.UIComponentBase.attributesThatAreSet", setAttributes);
			}
		}

		if (setAttributes != null && value == null) {
			final String attributeName = property.toString();
			final ValueExpression ve = getValueExpression(attributeName);
			if (ve == null) {
				setAttributes.remove(attributeName);
			} else if (!setAttributes.contains(attributeName)) {
				setAttributes.add(attributeName);
			}
		}
	}

	@Override
	public void processEvent(ComponentSystemEvent event) throws AbortProcessingException {
		super.processEvent(event);

		FacesContext fc = FacesContext.getCurrentInstance();
		if (!(event instanceof PostRestoreStateEvent) || !isSelectDetailRequest(fc)) {
			return;
		}

		String clienId = this.getClientId(fc);
		PartialViewContext pvc = fc.getPartialViewContext();

		// process and update the MasterDetail component automatically
		if (!isSkipProcessing(fc)) {
			pvc.getExecuteIds().add(clienId);
		}

		pvc.getRenderIds().add(clienId);

		MasterDetailLevel mdl = getDetailLevelToProcess(fc);
		Object contextValue = getContextValueFromFlow(fc, mdl);
		String contextVar = mdl.getContextVar();
		if (StringUtils.isNotBlank(contextVar) && contextValue != null) {
			Map<String, Object> requestMap = fc.getExternalContext().getRequestMap();
			requestMap.put(contextVar, contextValue);
		}
	}

	@Override
	public void processDecodes(final FacesContext fc) {
		if (!isSelectDetailRequest(fc)) {
			super.processDecodes(fc);
		} else {
			getDetailLevelToProcess(fc).processDecodes(fc);
		}
	}

	@Override
	public void processValidators(final FacesContext fc) {
		if (!isSelectDetailRequest(fc)) {
			super.processValidators(fc);
		} else {
			getDetailLevelToProcess(fc).processValidators(fc);
		}
	}

	@Override
	public void processUpdates(final FacesContext fc) {
		if (!isSelectDetailRequest(fc)) {
			super.processUpdates(fc);
		} else {
			getDetailLevelToProcess(fc).processUpdates(fc);
		}
	}

	public MasterDetailLevel getDetailLevelToProcess(final FacesContext fc) {
		if (detailLevelToProcess == null) {
			initDataForLevels(fc);
		}

		return detailLevelToProcess;
	}

	public MasterDetailLevel getDetailLevelToGo(final FacesContext fc) {
		if (detailLevelToGo != null) {
			return detailLevelToGo;
		}

		final String strSelectedLevel = fc.getExternalContext().getRequestParameterMap().get(getClientId(fc) + SELECTED_LEVEL);
		final String strSelectedStep = fc.getExternalContext().getRequestParameterMap().get(getClientId(fc) + SELECTED_STEP);

		// selected level != null
		if (strSelectedLevel != null) {
			int selectedLevel = Integer.valueOf(strSelectedLevel);
			detailLevelToGo = getDetailLevelByLevel(selectedLevel);
			if (detailLevelToGo != null) {
				return detailLevelToGo;
			}

			throw new FacesException("MasterDetailLevel for selected level = " + selectedLevel + " not found.");
		}

		int step;
		if (strSelectedStep != null) {
			// selected step != null
			step = Integer.valueOf(strSelectedStep);
		} else {
			// selected level and selected step are null ==> go to the next level
			step = 1;
		}

		detailLevelToGo = getDetailLevelByStep(step);

		return detailLevelToGo;
	}

	public MasterDetailLevel getDetailLevelByLevel(final int level) {
		for (UIComponent child : getChildren()) {
			if (child instanceof MasterDetailLevel) {
				MasterDetailLevel mdl = (MasterDetailLevel) child;
				if (mdl.getLevel() == level) {
					return mdl;
				}
			}
		}

		return null;
	}

	public boolean isSelectDetailRequest(final FacesContext fc) {
		return fc.getPartialViewContext().isAjaxRequest()
		       && fc.getExternalContext().getRequestParameterMap().containsKey(getClientId(fc) + SELECT_DETAIL_REQUEST);
	}

	public void updateModel(final FacesContext fc, final MasterDetailLevel mdlToGo) {
		final int levelToGo = mdlToGo.getLevel();
		ValueExpression levelVE = this.getValueExpression(PropertyKeys.level.toString());
		if (levelVE != null) {
			// update "level"
			levelVE.setValue(fc.getELContext(), levelToGo);
			getStateHelper().remove(PropertyKeys.level);
		}

		// get UICommand caused this ajax request
		final String source = fc.getExternalContext().getRequestParameterMap().get(Constants.PARTIAL_SOURCE_PARAM);
		MasterDetailLevel mdl = getDetailLevelToProcess(fc);

		// get resolved context value
		Object contextValue = null;
		@SuppressWarnings("unchecked")
		Map<String, Object> contextValues = (Map<String, Object>) mdl.getAttributes().get(CONTEXT_VALUES);
		if (contextValues != null) {
			contextValue = contextValues.get("contextValue_" + source);
		}

		if (contextValue != null) {
			// update current context value for corresponding MasterDetailLevel
			mdlToGo.getAttributes().put(getClientId(fc) + CURRENT_CONTEXT_VALUE, contextValue);

			// update "flow"
			ValueExpression flowVE = this.getValueExpression(PropertyKeys.flow.toString());
			if (flowVE != null) {
				Class flowType = flowVE.getType(fc.getELContext());

				if (!flowType.isArray()) {
					// we can also check Collection.class.isAssignableFrom(flowType), but a support of collection is too complicate
					// by reason of lack in Java Generics. The type of elements in a collection is not accessible at runtime.
					throw new FacesException("Type of the 'flow' attribute must be an Array.");
				}

				Class elementType = flowType.getComponentType();
				if (!FlowLevel.class.isAssignableFrom(elementType)) {
					throw new FacesException("Elements in the 'flow' array must implement 'FlowLevel' interface.");
				}

				try {
					FlowLevel newFlowLevel = (FlowLevel) elementType.newInstance();
					newFlowLevel.setLevel(levelToGo);
					newFlowLevel.setContextValue(contextValue);

					FlowLevel[] newFlow;
					Object objFlow = flowVE.getValue(fc.getELContext());

					if (objFlow == null) {
						newFlow = (FlowLevel[]) Array.newInstance(elementType, 1);
						newFlow[0] = newFlowLevel;
					} else {
						List<FlowLevel> listFlow = new ArrayList<FlowLevel>();
						listFlow.add(newFlowLevel);

						for (FlowLevel fl : (FlowLevel[]) objFlow) {
							if (fl.getLevel() != levelToGo) {
								listFlow.add(fl);
							}
						}

						newFlow = listFlow.toArray((FlowLevel[]) Array.newInstance(elementType, listFlow.size()));
					}

					flowVE.setValue(fc.getELContext(), newFlow);
					getStateHelper().remove(PropertyKeys.flow);
				} catch (Exception e) {
					throw new FacesException("Update of 'flow' array has failed.");
				}
			}
		}
	}

	public Object getContextValueFromFlow(final FacesContext fc, final MasterDetailLevel mdl) {
		// try to get context value from internal storage
		Object contextValue = mdl.getAttributes().get(this.getClientId(fc) + MasterDetail.CURRENT_CONTEXT_VALUE);
		if (contextValue != null) {
			return contextValue;
		}

		// try to get context value from external "flow" state
		FlowLevel[] flowLevels = (FlowLevel[]) this.getFlow();
		if (flowLevels != null && flowLevels.length > 0) {
			final int level = mdl.getLevel();
			for (FlowLevel fl : flowLevels) {
				if (fl.getLevel() == level) {
					return fl.getContextValue();
				}
			}
		}

		return null;
	}

	public void resetCalculatedValues() {
		detailLevelToProcess = null;
		detailLevelToGo = null;
		levelPositionToProcess = -1;
		levelCount = -1;
	}

	private void initDataForLevels(final FacesContext fc) {
		final String strCurrentLevel = fc.getExternalContext().getRequestParameterMap().get(getClientId(fc) + CURRENT_LEVEL);
		if (strCurrentLevel == null) {
			throw new FacesException("Current level is missing in request.");
		}

		int currentLevel = Integer.valueOf(strCurrentLevel);
		int count = 0;

		for (UIComponent child : getChildren()) {
			if (child instanceof MasterDetailLevel) {
				MasterDetailLevel mdl = (MasterDetailLevel) child;
				count++;

				if (detailLevelToProcess == null && mdl.getLevel() == currentLevel) {
					detailLevelToProcess = mdl;
					levelPositionToProcess = count;
				}
			}
		}

		levelCount = count;

		if (detailLevelToProcess == null) {
			throw new FacesException("Current MasterDetailLevel to process not found.");
		}
	}

	private boolean isSkipProcessing(final FacesContext fc) {
		return fc.getExternalContext().getRequestParameterMap().containsKey(getClientId(fc) + SKIP_PROCESSING_REQUEST);
	}

	private MasterDetailLevel getDetailLevelByStep(final int step) {
		int levelPositionToGo = getLevelPositionToProcess() + step;
		if (levelPositionToGo < 1) {
			levelPositionToGo = 1;
		} else if (levelPositionToGo > getLevelCount()) {
			levelPositionToGo = getLevelCount();
		}

		int pos = 0;
		for (UIComponent child : getChildren()) {
			if (child instanceof MasterDetailLevel) {
				MasterDetailLevel mdl = (MasterDetailLevel) child;
				pos++;

				if (pos == levelPositionToGo) {
					return mdl;
				}
			}
		}

		// should not happen
		return null;
	}

	private int getLevelPositionToProcess() {
		if (levelPositionToProcess == -1) {
			initDataForLevels(FacesContext.getCurrentInstance());
		}

		return levelPositionToProcess;
	}

	private int getLevelCount() {
		if (levelCount == -1) {
			initDataForLevels(FacesContext.getCurrentInstance());
		}

		return levelCount;
	}
}