Java tutorial
/* Copyright 2014 InterCommIT b.v. * * This file is part of the "Weaves" project hosted on https://github.com/intercommit/Weaves * * Weaves is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * any later version. * * Weaves is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with Weaves. If not, see <http://www.gnu.org/licenses/>. * */ package nl.intercommit.weaves.components; import org.apache.commons.lang.ArrayUtils; import org.apache.tapestry5.Binding; import org.apache.tapestry5.BindingConstants; import org.apache.tapestry5.ComponentResources; import org.apache.tapestry5.EventConstants; import org.apache.tapestry5.FieldValidationSupport; import org.apache.tapestry5.FieldValidator; import org.apache.tapestry5.Link; import org.apache.tapestry5.MarkupWriter; import org.apache.tapestry5.OptionModel; import org.apache.tapestry5.SelectModel; import org.apache.tapestry5.SelectModelVisitor; import org.apache.tapestry5.ValidationException; import org.apache.tapestry5.ValidationTracker; import org.apache.tapestry5.ValueEncoder; import org.apache.tapestry5.annotations.BeforeRenderTemplate; import org.apache.tapestry5.annotations.Environmental; import org.apache.tapestry5.annotations.Events; import org.apache.tapestry5.annotations.Mixin; import org.apache.tapestry5.annotations.Parameter; import org.apache.tapestry5.annotations.RequestParameter; import org.apache.tapestry5.corelib.base.AbstractField; import org.apache.tapestry5.corelib.data.BlankOption; import org.apache.tapestry5.corelib.mixins.RenderDisabled; import org.apache.tapestry5.internal.TapestryInternalUtils; import org.apache.tapestry5.internal.util.CaptureResultCallback; import org.apache.tapestry5.internal.util.SelectModelRenderer; import org.apache.tapestry5.ioc.Messages; import org.apache.tapestry5.ioc.annotations.Inject; import org.apache.tapestry5.ioc.internal.util.InternalUtils; import org.apache.tapestry5.json.JSONObject; import org.apache.tapestry5.services.ComponentDefaultProvider; import org.apache.tapestry5.services.FieldValidatorDefaultSource; import org.apache.tapestry5.services.FormSupport; import org.apache.tapestry5.services.Request; import org.apache.tapestry5.services.ValueEncoderFactory; import org.apache.tapestry5.services.ValueEncoderSource; import org.apache.tapestry5.services.javascript.JavaScriptSupport; import org.apache.tapestry5.util.EnumSelectModel; /** * Select an item from a list of values, using an [X]HTML <select> element on the client side. Any validation * decorations will go around the entire <select> element. * <p/> * A core part of this component is the {@link ValueEncoder} (the encoder parameter) that is used to convert between * server-side values and unique client-side strings. In some cases, a {@link ValueEncoder} can be generated automatically from * the type of the value parameter. The {@link ValueEncoderSource} service provides an encoder in these situations; it * can be overriden by binding the encoder parameter, or extended by contributing a {@link ValueEncoderFactory} into the * service's configuration. * * @tapestrydoc */ @Events({ EventConstants.VALIDATE, EventConstants.VALUE_CHANGED + " when 'zone' parameter is bound" }) public class EnhancedSelect extends AbstractField { public static final String CHANGE_EVENT = "change"; private class Renderer extends SelectModelRenderer { public Renderer(MarkupWriter writer) { super(writer, encoder); } @Override protected boolean isOptionSelected(OptionModel optionModel, String clientValue) { return isSelected(clientValue); } } /** * A ValueEncoder used to convert the server-side object provided by the * "value" parameter into a unique client-side string (typically an ID) and * back. Note: this parameter may be OMITTED if Tapestry is configured to * provide a ValueEncoder automatically for the type of property bound to * the "value" parameter. * * @see ValueEncoderSource */ @Parameter private ValueEncoder encoder; @Parameter(value = "false") private boolean multiple; /** * The separator used to split a multi value field ,defaults to 'space' ' ' */ @Parameter(defaultPrefix = BindingConstants.LITERAL, value = "literal: ") private String multiSeparator; @Inject private ComponentDefaultProvider defaultProvider; // Maybe this should default to property "<componentId>Model"? /** * The model used to identify the option groups and options to be presented to the user. This can be generated * automatically for Enum types. */ @Parameter(required = true, allowNull = false) private SelectModel model; /** * Controls whether an additional blank option is provided. The blank option precedes all other options and is never * selected. The value for the blank option is always the empty string, the label may be the blank string; the * label is from the blankLabel parameter (and is often also the empty string). */ @Parameter(value = "auto", defaultPrefix = BindingConstants.LITERAL) private BlankOption blankOption; /** * The label to use for the blank option, if rendered. If not specified, the container's message catalog is * searched for a key, <code><em>id</em>-blanklabel</code>. */ @Parameter(defaultPrefix = BindingConstants.LITERAL) private String blankLabel; @Inject private Request request; @Inject private ComponentResources resources; @Environmental private ValidationTracker tracker; /** * Performs input validation on the value supplied by the user in the form submission. */ @Parameter(defaultPrefix = BindingConstants.VALIDATE) private FieldValidator<Object> validate; /** * The value to read or update. */ @Parameter(required = true, principal = true, autoconnect = true) private Object value; /** * Binding the zone parameter will cause any change of Select's value to be handled as an Ajax request that updates * the * indicated zone. The component will trigger the event {@link EventConstants#VALUE_CHANGED} to inform its * container that Select's value has changed. * * @since 5.2.0 */ @Parameter(defaultPrefix = BindingConstants.LITERAL) private String zone; @Inject private FieldValidationSupport fieldValidationSupport; @Environmental private FormSupport formSupport; @Inject private JavaScriptSupport javascriptSupport; @SuppressWarnings("unused") @Mixin private RenderDisabled renderDisabled; private String selectedClientValue; private boolean isSelected(String clientValue) { if (multiple) { if (org.apache.commons.lang.StringUtils.isNotBlank(selectedClientValue)) { return ArrayUtils.contains(selectedClientValue.split(multiSeparator), clientValue); } } return TapestryInternalUtils.isEqual(clientValue, selectedClientValue); } @SuppressWarnings({ "unchecked" }) @Override protected void processSubmission(String controlName) { String submittedValue = null; // my multivalue hack if (multiple) { submittedValue = ArrayUtils.toString(request.getParameters(controlName)); System.err.println("submittewd:" + submittedValue); System.err.println("SEPARATER: '" + multiSeparator + "'"); submittedValue = submittedValue.replace(",", multiSeparator); submittedValue = submittedValue.substring(1, submittedValue.length() - 1); } else { submittedValue = request.getParameter(controlName); } tracker.recordInput(this, submittedValue); Object selectedValue = toValue(submittedValue); putPropertyNameIntoBeanValidationContext("value"); try { fieldValidationSupport.validate(selectedValue, resources, validate); value = selectedValue; } catch (ValidationException ex) { tracker.recordError(this, ex.getMessage()); } removePropertyNameFromBeanValidationContext(); } void afterRender(MarkupWriter writer) { writer.end(); } void beginRender(MarkupWriter writer) { if (multiple) { writer.element("select", "name", getControlName(), "id", getClientId(), "multiple", "true"); } else { writer.element("select", "name", getControlName(), "id", getClientId()); } putPropertyNameIntoBeanValidationContext("value"); validate.render(writer); removePropertyNameFromBeanValidationContext(); resources.renderInformalParameters(writer); decorateInsideField(); // Disabled is via a mixin if (this.zone != null) { Link link = resources.createEventLink(CHANGE_EVENT); JSONObject spec = new JSONObject("selectId", getClientId(), "zoneId", zone, "url", link.toURI()); javascriptSupport.addInitializerCall("linkSelectToZone", spec); } } Object onChange(@RequestParameter(value = "t:selectvalue", allowBlank = true) final String selectValue) { final Object newValue = toValue(selectValue); CaptureResultCallback<Object> callback = new CaptureResultCallback<Object>(); this.resources.triggerEvent(EventConstants.VALUE_CHANGED, new Object[] { newValue }, callback); this.value = newValue; return callback.getResult(); } protected Object toValue(String submittedValue) { return InternalUtils.isBlank(submittedValue) ? null : this.encoder.toValue(submittedValue); } @SuppressWarnings("unchecked") ValueEncoder defaultEncoder() { return defaultProvider.defaultValueEncoder("value", resources); } @SuppressWarnings("unchecked") SelectModel defaultModel() { Class valueType = resources.getBoundType("value"); if (valueType == null) return null; if (Enum.class.isAssignableFrom(valueType)) return new EnumSelectModel(valueType, resources.getContainerMessages()); return null; } /** * Computes a default value for the "validate" parameter using {@link FieldValidatorDefaultSource}. */ Binding defaultValidate() { return defaultProvider.defaultValidatorBinding("value", resources); } Object defaultBlankLabel() { Messages containerMessages = resources.getContainerMessages(); String key = resources.getId() + "-blanklabel"; if (containerMessages.contains(key)) return containerMessages.get(key); return null; } /** * Renders the options, including the blank option. */ @BeforeRenderTemplate void options(MarkupWriter writer) { selectedClientValue = tracker.getInput(this); // Use the value passed up in the form submission, if available. // Failing that, see if there is a current value (via the value parameter), and // convert that to a client value for later comparison. if (selectedClientValue == null) selectedClientValue = value == null ? null : encoder.toClient(value); if (showBlankOption()) { writer.element("option", "value", ""); writer.write(blankLabel); writer.end(); } SelectModelVisitor renderer = new Renderer(writer); model.visit(renderer); } @Override public boolean isRequired() { return validate.isRequired(); } private boolean showBlankOption() { switch (blankOption) { case ALWAYS: return true; case NEVER: return false; default: return !isRequired(); } } // For testing. void setModel(SelectModel model) { this.model = model; blankOption = BlankOption.NEVER; } void setValue(Object value) { this.value = value; } void setValueEncoder(ValueEncoder encoder) { this.encoder = encoder; } void setValidationTracker(ValidationTracker tracker) { this.tracker = tracker; } void setBlankOption(BlankOption option, String label) { blankOption = option; blankLabel = label; } }