com.conwax.ajax.SimpleAjaxRequestTarget.java Source code

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Here is the source code for com.conwax.ajax.SimpleAjaxRequestTarget.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
package com.conwax.ajax;

import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.http.WebResponse;
import org.apache.wicket.util.lang.Args;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SimpleAjaxRequestTarget implements IRequestHandler {

    private static final Logger LOG = LoggerFactory.getLogger(SimpleAjaxRequestTarget.class);

    /**
     * The component instance that will be rendered/replaced.
     */
    protected Component component;

    public void setComponent(Component component) {
        Args.notNull(component, "component");

        if (component.getOutputMarkupId() == false && !(component instanceof Page)) {
            throw new IllegalArgumentException(
                    "cannot update component that does not have setOutputMarkupId property set to true. Component: "
                            + component.toString());
        }
        this.component = component;
    }

    public void respond(IRequestCycle requestCycle) {
        final WebResponse response = (WebResponse) requestCycle.getResponse();

        response.reset();
        // Make sure it is not cached by a client
        response.disableCaching();

        if (component.getRenderBodyOnly() == true) {
            throw new IllegalStateException(
                    "Ajax render cannot be called on component that has setRenderBodyOnly enabled. Component: "
                            + component.toString());
        }

        component.setOutputMarkupId(true);

        // Initialize temporary variables
        final Page page = component.findParent(Page.class);
        if (page == null) {
            // dont throw an exception but just ignore this component,
            // somehow
            // it got removed from the page.
            LOG.debug("component: " + component + " with markupid: " + component.getMarkupId()
                    + " not rendered because it was already removed from page");
            return;
        }

        page.startComponentRender(component);

        try {
            component.prepareForRender();

            // render any associated headers of the component
            // forget about Header Contribs
            // writeHeaderContribution(response, component);
        } catch (RuntimeException e) {
            try {
                component.afterRender();
            } catch (RuntimeException e2) {
                // ignore this one could be a result off.
            }
            throw e;
        }

        try {
            component.render();
        } catch (RuntimeException e) {
            response.reset();
            throw e;
        }

        page.endComponentRender(component);

    }

    public void detach(IRequestCycle requestCycle) {
        // do nothing
    }
}