001    // Copyright 2008, 2010, 2011 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.corelib.components;
016    
017    import org.apache.tapestry5.ComponentResources;
018    import org.apache.tapestry5.MarkupWriter;
019    import org.apache.tapestry5.annotations.Environmental;
020    import org.apache.tapestry5.annotations.SupportsInformalParameters;
021    import org.apache.tapestry5.corelib.internal.AjaxFormLoopContext;
022    import org.apache.tapestry5.ioc.annotations.Inject;
023    import org.apache.tapestry5.services.javascript.JavaScriptSupport;
024    
025    /**
026     * Used inside an {@link org.apache.tapestry5.corelib.components.AjaxFormLoop} component to spur the addition of a new
027     * row. Triggers a server-side {@linkplain org.apache.tapestry5.EventConstants#ADD_ROW addRow} event on the
028     * AjaxFormLoop, which must return the newly added object, which will be rendered in the body of the AjaxFormLoop and
029     * sent to the client web browser.
030     * 
031     * @tapestrydoc
032     */
033    @SupportsInformalParameters
034    public class AddRowLink
035    {
036        @Environmental
037        private AjaxFormLoopContext context;
038    
039        @Inject
040        private JavaScriptSupport jsSupport;
041    
042        @Inject
043        private ComponentResources resources;
044    
045        void beginRender(MarkupWriter writer)
046        {
047            String id = jsSupport.allocateClientId(resources);
048    
049            writer.element("a", "id", id, "href", "#");
050            resources.renderInformalParameters(writer);
051    
052            context.addAddRowTrigger(id);
053        }
054    
055        void afterRender(MarkupWriter writer)
056        {
057            writer.end();
058        }
059    }