001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.extensions.markup.html.repeater.data.table.filter;
018
019import org.apache.wicket.Component;
020import org.apache.wicket.behavior.Behavior;
021import org.apache.wicket.markup.ComponentTag;
022import org.apache.wicket.markup.MarkupStream;
023import org.apache.wicket.markup.head.IHeaderResponse;
024import org.apache.wicket.markup.head.JavaScriptHeaderItem;
025import org.apache.wicket.markup.head.OnLoadHeaderItem;
026import org.apache.wicket.markup.html.form.Form;
027import org.apache.wicket.markup.html.form.FormComponent;
028import org.apache.wicket.request.resource.JavaScriptResourceReference;
029import org.apache.wicket.request.resource.ResourceReference;
030import org.apache.wicket.util.string.Strings;
031
032/**
033 * A form with filter-related special functionality for its form components.
034 *
035 * <p>
036 * This form uses an invisible button to be able to submit when the user presses the <em>ENTER</em>
037 * key. If there is a need to add an explicit
038 * {@link org.apache.wicket.markup.html.form.IFormSubmittingComponent} to this form then
039 * {@link Form#setDefaultButton(org.apache.wicket.markup.html.form.IFormSubmittingComponent)} should
040 * be used to specify this custom submitting component.
041 * </p>
042 *
043 * @param <T>
044 *            type of filter state object
045 * @author igor
046 */
047public class FilterForm<T> extends Form<T>
048{
049        private static final long serialVersionUID = 1L;
050
051        private static final ResourceReference JS = new JavaScriptResourceReference(FilterForm.class,
052                "wicket-filterform.js");
053
054        private final IFilterStateLocator<T> locator;
055
056        /**
057         * @param id
058         *            component id
059         * @param locator
060         *            filter state locator
061         */
062        public FilterForm(final String id, final IFilterStateLocator<T> locator)
063        {
064                super(id, new FilterStateModel<>(locator));
065
066                this.locator = locator;
067        }
068
069        @Override
070        public void renderHead(final IHeaderResponse response)
071        {
072                super.renderHead(response);
073
074                response.render(JavaScriptHeaderItem.forReference(JS));
075
076                response.render(OnLoadHeaderItem.forScript(String.format(
077                        "Wicket.FilterForm.restore('%s');", getFocusTrackerFieldCssId())));
078        }
079
080        /**
081         * {@inheritDoc}
082         */
083        @Override
084        public void onComponentTagBody(final MarkupStream markupStream, final ComponentTag openTag)
085        {
086                super.onComponentTagBody(markupStream, openTag);
087
088                getResponse().write(generateHiddenInputMarkup());
089        }
090
091        /**
092         * Generates the Markup for the hidden input. Can be overridden by subclasses if necessary.
093         *
094         * @return The markup to be appended to the response
095         */
096        protected String generateHiddenInputMarkup() {
097                String id = Strings.escapeMarkup(getFocusTrackerFieldCssId()).toString();
098                String value = getRequest().getPostParameters().getParameterValue(id).toString("");
099                String cssClass = getString(Form.HIDDEN_FIELDS_CSS_CLASS_KEY);
100
101                return String.format(
102                                "<div hidden='' class='%s'><input type='hidden' name='%s' id='%s' value='%s'/><input type='submit'/></div>",
103                                cssClass, id, id, Strings.escapeMarkup(value));
104        }
105
106        /**
107         * @return css id of the hidden form input that keeps track of the focused input field
108         */
109        public final String getFocusTrackerFieldCssId()
110        {
111                return getMarkupId() + "focus";
112        }
113
114        /**
115         * @return IFilterStateLocator passed to this form
116         */
117        public final IFilterStateLocator<T> getStateLocator()
118        {
119                return locator;
120        }
121
122        /**
123         * Adds behavior to the form component to allow this form to keep track of the component's focus
124         * which will be restored after a form submit.
125         *
126         * @param fc
127         *            form component
128         */
129        public final void enableFocusTracking(final FormComponent<?> fc)
130        {
131                fc.add(new Behavior()
132                {
133                        private static final long serialVersionUID = 1L;
134
135                        @Override
136                        public void bind(Component component)
137                        {
138                                super.bind(component);
139                                component.setOutputMarkupId(true);
140                        }
141
142                        @Override
143                        public void onComponentTag(final Component component, final ComponentTag tag)
144                        {
145                                tag.put("onfocus", getFocusTrackingHandler(component));
146
147                                super.onComponentTag(component, tag);
148                        }
149                });
150        }
151
152        /**
153         * Returns the javascript focus handler necessary to notify the form of focus tracking changes
154         * on the component
155         *
156         * Useful when components want to participate in focus tracking but want to add the handler
157         * their own way.
158         *
159         * A unique css id is required on the form component for focus tracking to work.
160         *
161         * @param component
162         *            component to
163         * @return the javascript focus handler necessary to notify the form of focus tracking changes
164         *         on the component
165         */
166        public final String getFocusTrackingHandler(final Component component)
167        {
168                return String.format("Wicket.FilterForm.focused(this, '%s');", getFocusTrackerFieldCssId());
169        }
170}