Java tutorial
/********************************************************************************** * * $Id$ * *********************************************************************************** * * Copyright (c) 2005, 2006, 2007, 2008 The Sakai Foundation, The MIT Corporation * * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.tool.gradebook.ui; import java.io.Serializable; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.List; import java.util.Map; import javax.faces.event.ActionEvent; import javax.faces.model.SelectItem; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.sakaiproject.service.gradebook.shared.StaleObjectModificationException; import org.sakaiproject.tool.gradebook.GradeMapping; import org.sakaiproject.tool.gradebook.Gradebook; import org.sakaiproject.tool.gradebook.jsf.FacesUtil; import org.sakaiproject.service.gradebook.shared.GradebookService; /** * Provides support for the student feedback options page, which also controls * grade-to-percentage mappings for the gradebook. */ public class FeedbackOptionsBean extends GradebookDependentBean implements Serializable { private static final Log log = LogFactory.getLog(FeedbackOptionsBean.class); // View maintenance fields - serializable. /** * This is the one page in which the user can change what's on the screen * and have their current working inputs remembered without updating the * database. In other words, this is currently our only "what if?" workflow. * The following variable keeps bean initialization from overwriting stable * input fields from the database. */ private boolean workInProgress; /** Cache a copy of the gradebook object in the request thread, to keep track of all grade mapping changes */ private Gradebook localGradebook; private Long selectedGradeMappingId; /** The list of select box items */ private List gradeMappingsSelectItems; // View into row-specific data. private List gradeRows; private boolean isValidWithLetterGrade = true; public class GradeRow implements Serializable { private GradeMapping gradeMapping; private String grade; private boolean editable; public GradeRow() { } public GradeRow(GradeMapping gradeMapping, String grade, boolean editable) { this.gradeMapping = gradeMapping; this.grade = grade; this.editable = editable; } public String getGrade() { return grade; } public Double getMappingValue() { return (Double) gradeMapping.getGradeMap().get(grade); } public void setMappingValue(Double value) { gradeMapping.getGradeMap().put(grade, value); } public boolean isGradeEditable() { return editable; } } public Gradebook getLocalGradebook() { return localGradebook; } /** * Initializes this backing bean. */ protected void init() { if (!workInProgress) { localGradebook = getGradebookManager().getGradebookWithGradeMappings(getGradebookId()); // Load the grade mappings, sorted by name. List gradeMappings = new ArrayList(localGradebook.getGradeMappings()); Collections.sort(gradeMappings); // Create the grade type drop-down menu gradeMappingsSelectItems = new ArrayList(gradeMappings.size()); for (Iterator iter = gradeMappings.iterator(); iter.hasNext();) { GradeMapping gradeMapping = (GradeMapping) iter.next(); gradeMappingsSelectItems.add(new SelectItem(gradeMapping.getId(), gradeMapping.getName())); } // set the selected grade mapping GradeMapping selectedGradeMapping = localGradebook.getSelectedGradeMapping(); selectedGradeMappingId = selectedGradeMapping.getId(); initGradeRows(); } // Set the view state. workInProgress = true; } private void initGradeRows() { // Set up UI table view. gradeRows = new ArrayList(); GradeMapping selectedGradeMapping = localGradebook.getSelectedGradeMapping(); for (Iterator iter = selectedGradeMapping.getGrades().iterator(); iter.hasNext();) { String grade = (String) iter.next(); // Bottom grades (with a lower bound of 0%) and manual-only // grades (which have no percentage equivalent) are not // editable. Double d = selectedGradeMapping.getDefaultBottomPercents().get(grade); boolean editable = ((d != null) && (d.doubleValue() > 0.0)); gradeRows.add(new GradeRow(selectedGradeMapping, grade, editable)); } } public List getGradeRows() { return gradeRows; } public void setGradeRows(List gradeRows) { this.gradeRows = gradeRows; } /** * Action listener to view a different grade type mapping. * According to the specification, we do not update any changed values in the currently * shown mapping, but we do remember them. */ public void changeGradeType(ActionEvent event) { isValidWithLetterGrade = true; for (Iterator iter = localGradebook.getGradeMappings().iterator(); iter.hasNext();) { GradeMapping mapping = (GradeMapping) iter.next(); if (mapping.getId().equals(selectedGradeMappingId)) { if (localGradebook.getGrade_type() == GradebookService.GRADE_TYPE_LETTER && mapping.getGradingScale().getUid().equals("LetterGradeMapping")) { isValidWithLetterGrade = false; return; } localGradebook.setSelectedGradeMapping(mapping); initGradeRows(); } } } /** * Action listener to reset the currently selected grade mapping to its default values. * Other, not currently visible, changed unsaved grade mapping settings are left as they * are. */ public void resetMappingValues(ActionEvent event) { localGradebook.getSelectedGradeMapping().setDefaultValues(); } /** * Updates the gradebook to reflect the currently selected grade type and mapping. */ public String save() { if (!isMappingValid(localGradebook.getSelectedGradeMapping())) { return null; } if (!isConflictWithLetterGrade(localGradebook.getSelectedGradeMapping())) { isValidWithLetterGrade = false; return null; } else isValidWithLetterGrade = true; try { getGradebookManager().updateGradebook(localGradebook); FacesUtil.addRedirectSafeMessage(getLocalizedString("feedback_options_submit_success")); } catch (IllegalStateException ise) { FacesUtil.addErrorMessage(getLocalizedString("feedback_options_illegal_change", new String[] { localGradebook.getSelectedGradeMapping().getName() })); return null; } catch (StaleObjectModificationException e) { log.error(e); FacesUtil.addErrorMessage(getLocalizedString("feedback_options_locking_failure")); return null; } return "overview"; } private boolean isMappingValid(GradeMapping gradeMapping) { boolean valid = true; Double previousPercentage = null; for (Iterator iter = gradeMapping.getGrades().iterator(); iter.hasNext();) { String grade = (String) iter.next(); Double percentage = (Double) gradeMapping.getValue(grade); if (log.isDebugEnabled()) log.debug("checking percentage " + percentage + " for validity"); // Grades that are percentage-based need to remain percentage-based, // be in descending order, and end with 0. // Manual-only grades (which aren't associated with a percentage) always // follow the lowest percentage-based grade, and must stay manual-only. boolean manualOnly = (gradeMapping.getDefaultBottomPercents().get(grade) == null); if (manualOnly) { if (percentage != null) { // This shouldn't happen, given the UI. if (log.isErrorEnabled()) log.error("User " + getUserUid() + " attempted to set manual-only grade '" + grade + "' to be worth " + percentage + " percent"); percentage = null; valid = false; } } else { if (percentage == null) { FacesUtil.addUniqueErrorMessage(getLocalizedString("feedback_options_require_all_values")); valid = false; } else if (percentage.doubleValue() < 0) { FacesUtil.addUniqueErrorMessage(getLocalizedString("feedback_options_require_positive")); valid = false; } else if ((previousPercentage != null) && (previousPercentage.doubleValue() < percentage.doubleValue())) { FacesUtil .addUniqueErrorMessage(getLocalizedString("feedback_options_require_descending_order")); valid = false; } } previousPercentage = percentage; } return valid; } private boolean isConflictWithLetterGrade(GradeMapping gradeMapping) { boolean valid = true; if (localGradebook.getGrade_type() != GradebookService.GRADE_TYPE_LETTER) { return valid; } if ((gradeMapping.getGradingScale() != null && (!gradeMapping.getGradingScale().getUid().equals("LetterGradeMapping") && !gradeMapping.getGradingScale().getUid().equals("LetterGradePlusMinusMapping"))) || (gradeMapping.getGradingScale() == null && (!gradeMapping.getName().equals("Letter Grades") && !gradeMapping.getName().equals("Letter Grades with +/-")))) { return valid; } Map defaultMapping = gradeMapping.getDefaultBottomPercents(); for (Iterator iter = gradeMapping.getGrades().iterator(); iter.hasNext();) { String grade = (String) iter.next(); Double percentage = (Double) gradeMapping.getValue(grade); Double defautPercentage = (Double) defaultMapping.get(grade); if (log.isDebugEnabled()) log.debug("checking if percentage is being changed for letter grade type gradebook: " + percentage + " for validity"); if (percentage == null) { FacesUtil.addUniqueErrorMessage(getLocalizedString("feedback_options_require_all_values")); valid = false; } else { if (!percentage.equals(defautPercentage)) { valid = false; } } } return valid; } public String cancel() { // Just in case we change the navigation to stay on this page, // clear the work-in-progress indicator so that the user can // start fresh. workInProgress = false; isValidWithLetterGrade = true; return "overview"; } public List getGradeMappingsSelectItems() { return gradeMappingsSelectItems; } public void setGradeMappingsSelectItems(List gradeMappingsSelectItems) { this.gradeMappingsSelectItems = gradeMappingsSelectItems; } public Long getSelectedGradeMappingId() { return selectedGradeMappingId; } public void setSelectedGradeMappingId(Long selectedGradeMappingId) { this.selectedGradeMappingId = selectedGradeMappingId; } public boolean getIsValidWithLetterGrade() { return isValidWithLetterGrade; } public void setIsValidWithLetterGrade(boolean isValidWithLetterGrade) { this.isValidWithLetterGrade = isValidWithLetterGrade; } }