tapestry-core/src/main/java/org/apache/tapestry5/corelib/components/Zone.java - tapestry-5 - Git at Google

 // Licensed 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 org.apache.tapestry5.corelib.components;

 import org.apache.tapestry5.*;
 import org.apache.tapestry5.annotations.*;
 import org.apache.tapestry5.corelib.internal.ComponentActionSink;
 import org.apache.tapestry5.corelib.internal.FormSupportAdapter;
 import org.apache.tapestry5.corelib.internal.HiddenFieldPositioner;
 import org.apache.tapestry5.dom.Element;
 import org.apache.tapestry5.internal.services.RequestConstants;
 import org.apache.tapestry5.ioc.annotations.Inject;
 import org.apache.tapestry5.ioc.annotations.Symbol;
 import org.apache.tapestry5.json.JSONObject;
 import org.apache.tapestry5.services.*;
 import org.apache.tapestry5.services.compatibility.DeprecationWarning;
 import org.apache.tapestry5.services.javascript.JavaScriptSupport;
 import org.slf4j.Logger;

 /**
  * A Zone is portion of the output page designed for easy dynamic updating via Ajax or other client-side effects. A
  * Zone renders out as a &lt;div&gt; element (or whatever is specified in the template) and may have content initially,
  * or may only get its content as a result of client side activity.
  *
  * When a user clicks an {@link org.apache.tapestry5.corelib.components.ActionLink} whose zone parameter is set triggers a
  * series of client-side behaviors, and an Ajax request to the server.
  *
  * The server side event handler can return a {@link org.apache.tapestry5.Block} or a component to render as the new
  * content on the client side. Often, re-rendering the Zone's {@linkplain #getBody() body} is useful. Multiple
  * client-side zones may be updated via the {@link org.apache.tapestry5.services.ajax.AjaxResponseRenderer} service.
  *
  * You will often want to specify the id parameter of the Zone, in addition to its Tapestry component id; this "locks
  * down" the client-side id, so the same value is used even in later partial renders of the page (essential if the Zone
  * is nested inside another Zone). When you specify the client-side id, it is used exactly as provided (meaning that you
  * are responsible for ensuring that there will not be an id conflict even in the face of multiple partial renders of
  * the page). Failure to provide an explicit id results in a new, and non-predictable, id being generated for each
  * partial render, which will often result in client-side failures to locate the element to update when the Zone is
  * triggered.
  *
  * In some cases, you may want to know (on the server side) the client id of the zone that was updated; this is passed
  * as part of the Ajax request, as the {@link QueryParameterConstants#ZONE_ID} parameter. An example use of this would
  * be to provide new content into a Zone that updates the same Zone, when the Zone's client-side id is dynamically
  * allocated (rather than statically defined). In most cases, however, the programmer is responsible for assigning a
  * specific client-side id, via the id parameter.
  *
  * A Zone starts and stops a {@link Heartbeat} when it renders (both normally, and when re-rendering).
  *
  * After the client-side content is updated, a client-side event is fired on the zone's element. The constant
  * <code>core/events:zone.didUpdate</code> can be used to listen to the event.
  *
  * @tapestrydoc
  * @see AjaxFormLoop
  * @see FormFragment
  */
 @SupportsInformalParameters
 @Import(module = "t5/core/zone")
 public class Zone implements ClientBodyElement
 {
     /**
      * Name of a function on the client-side Tapestry.ElementEffect object that is invoked to make the Zone's
      * &lt;div&gt; visible before being updated. If not specified, then the basic "show" method is used.
      *
      * @deprecated In 5.4, with no specific replacement, now does nothing (see notes on client-side JavaScript events, elsewhere)
      */
     @Parameter(defaultPrefix = BindingConstants.LITERAL)
     private String show;

     /**
      * Name of a function on the client-side Tapestry.ElementEffect object that is invoked after the Zone's content has
      * been updated. If not specified, then the basic "highlight" method is used, which performs a classic "yellow fade"
      * to indicate to the user that and update has taken place.
      *
      * @deprecated In 5.4, with no specific replacement, now does nothing (see notes on client-side JavaScript events, elsewhere)
      */
     @Parameter(defaultPrefix = BindingConstants.LITERAL)
     private String update;

     /**
      * The element name to render for the zone; this defaults to the element actually used in the template, or "div" if
      * no specific element was specified.
      */
     @Parameter(required = true, allowNull = false, defaultPrefix = BindingConstants.LITERAL)
     private String elementName;

     /**
      * If bound, then the id attribute of the rendered element will be this exact value. If not bound, then a unique id
      * is generated for the element.
      */
     @Parameter(name = "id", defaultPrefix = BindingConstants.LITERAL)
     private String idParameter;

     @Environmental
     private JavaScriptSupport javascriptSupport;

     @Inject
     private Environment environment;

     /**
      * In prior releases, this parameter could be overridden to false to force the outer element of the rendered
      * Zone to be non-visible. This behavior is no longer supported.
      *
      * @deprecated Deprecated in 5.4 with no replacement.
      */
     @Parameter
     private boolean visible;

     /**
      * if set to true, then Ajax updates related to this Zone will, when rending, use simple IDs (not namespaced ids).
      * This is useful when the Zone contains a simple Form, as it (hopefully) ensures that the same ids used when
      * initially rendering, and when processing the submission, are also used when re-rendering the Form (to present
      * errors to the user).  The default is false, maintaining the same behavior as in Tapestry 5.3 and earlier.
      *
      * @since 5.4
      */
     @Parameter
     private boolean simpleIds;

     @Inject
     private ComponentResources resources;

     @Inject
     private Heartbeat heartbeat;

     @Inject
     private Logger logger;

     @Inject
     private ClientDataEncoder clientDataEncoder;

     @Inject
     private HiddenFieldLocationRules rules;

     private String clientId;

     private boolean insideForm;

     private HiddenFieldPositioner hiddenFieldPositioner;

     private ComponentActionSink actionSink;

     @Environmental(false)
     private FormSupport formSupport;

     @Inject
     private DeprecationWarning deprecationWarning;

     @Inject
     @Symbol(SymbolConstants.COMPACT_JSON)
     private boolean compactJSON;

     String defaultElementName()
     {
         return resources.getElementName("div");
     }

     void pageLoaded()
     {
         deprecationWarning.ignoredComponentParameters(resources, "show", "update", "visible");
     }

     void beginRender(MarkupWriter writer)
     {
         clientId = resources.isBound("id") ? idParameter : javascriptSupport.allocateClientId(resources);

         Element e = writer.element(elementName,
                 "id", clientId,
                 "data-container-type", "zone");

         if (simpleIds)
         {
             e.attribute("data-simple-ids", "true");
         }

         resources.renderInformalParameters(writer);

         insideForm = formSupport != null;

         if (insideForm)
         {
             JSONObject parameters = new JSONObject(RequestConstants.FORM_CLIENTID_PARAMETER, formSupport.getClientId(),
                     RequestConstants.FORM_COMPONENTID_PARAMETER, formSupport.getFormComponentId());

             e.attribute("data-zone-parameters",
                     parameters.toString(compactJSON));

             hiddenFieldPositioner = new HiddenFieldPositioner(writer, rules);

             actionSink = new ComponentActionSink(logger, clientDataEncoder);

             environment.push(FormSupport.class, new FormSupportAdapter(formSupport)
             {
                 @Override
                 public <T> void store(T component, ComponentAction<T> action)
                 {
                     actionSink.store(component, action);
                 }

                 @Override
                 public <T> void storeCancel(T component, ComponentAction<T> action)
                 {
                     actionSink.storeCancel(component, action);
                 }

                 @Override
                 public <T> void storeAndExecute(T component, ComponentAction<T> action)
                 {
                     store(component, action);

                     action.execute(component);
                 }

             });
         }

         heartbeat.begin();
     }

     void afterRender(MarkupWriter writer)
     {
         heartbeat.end();

         if (insideForm)
         {
             environment.pop(FormSupport.class);

             if (actionSink.isEmpty())
             {
                 hiddenFieldPositioner.discard();
             } else
             {
                 hiddenFieldPositioner.getElement().attributes("type", "hidden",

                         "name", Form.FORM_DATA,

                         "value", actionSink.getClientData());
             }
         }

         writer.end(); // div
     }

     /**
      * The client id of the Zone; this is set when the Zone renders and will either be the value bound to the id
      * parameter, or an allocated unique id. When the id parameter is bound, this value is always accurate.
      * When the id parameter is not bound, the clientId is set during the {@linkplain BeginRender begin render phase}
      * and will be null or inaccurate before then.
      *
      * @return client-side element id
      */
     public String getClientId()
     {
         if (resources.isBound("id"))
             return idParameter;

         // TAP4-2342. I know this won't work with a Zone with no given clientId and that was already
         // via AJAX inside an outer Zone, but it's still better than nothing.
         if (clientId == null)
         {
             clientId = resources.getId();
         }

         return clientId;
     }

     /**
      * Returns the zone's body (the content enclosed by its start and end tags). This is often used as part of an Ajax
      * partial page render to update the client with a fresh render of the content inside the zone.
      *
      * @return the zone's body as a Block
      */
     public Block getBody()
     {
         return resources.getBody();
     }
 }
	// Licensed 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 org.apache.tapestry5.corelib.components;

	import org.apache.tapestry5.*;
	import org.apache.tapestry5.annotations.*;
	import org.apache.tapestry5.corelib.internal.ComponentActionSink;
	import org.apache.tapestry5.corelib.internal.FormSupportAdapter;
	import org.apache.tapestry5.corelib.internal.HiddenFieldPositioner;
	import org.apache.tapestry5.dom.Element;
	import org.apache.tapestry5.internal.services.RequestConstants;
	import org.apache.tapestry5.ioc.annotations.Inject;
	import org.apache.tapestry5.ioc.annotations.Symbol;
	import org.apache.tapestry5.json.JSONObject;
	import org.apache.tapestry5.services.*;
	import org.apache.tapestry5.services.compatibility.DeprecationWarning;
	import org.apache.tapestry5.services.javascript.JavaScriptSupport;
	import org.slf4j.Logger;

	/**
	* A Zone is portion of the output page designed for easy dynamic updating via Ajax or other client-side effects. A
	* Zone renders out as a <div> element (or whatever is specified in the template) and may have content initially,
	* or may only get its content as a result of client side activity.
	*
	* When a user clicks an {@link org.apache.tapestry5.corelib.components.ActionLink} whose zone parameter is set triggers a
	* series of client-side behaviors, and an Ajax request to the server.
	*
	* The server side event handler can return a {@link org.apache.tapestry5.Block} or a component to render as the new
	* content on the client side. Often, re-rendering the Zone's {@linkplain #getBody() body} is useful. Multiple
	* client-side zones may be updated via the {@link org.apache.tapestry5.services.ajax.AjaxResponseRenderer} service.
	*
	* You will often want to specify the id parameter of the Zone, in addition to its Tapestry component id; this "locks
	* down" the client-side id, so the same value is used even in later partial renders of the page (essential if the Zone
	* is nested inside another Zone). When you specify the client-side id, it is used exactly as provided (meaning that you
	* are responsible for ensuring that there will not be an id conflict even in the face of multiple partial renders of
	* the page). Failure to provide an explicit id results in a new, and non-predictable, id being generated for each
	* partial render, which will often result in client-side failures to locate the element to update when the Zone is
	* triggered.
	*
	* In some cases, you may want to know (on the server side) the client id of the zone that was updated; this is passed
	* as part of the Ajax request, as the {@link QueryParameterConstants#ZONE_ID} parameter. An example use of this would
	* be to provide new content into a Zone that updates the same Zone, when the Zone's client-side id is dynamically
	* allocated (rather than statically defined). In most cases, however, the programmer is responsible for assigning a
	* specific client-side id, via the id parameter.
	*
	* A Zone starts and stops a {@link Heartbeat} when it renders (both normally, and when re-rendering).
	*
	* After the client-side content is updated, a client-side event is fired on the zone's element. The constant
	* <code>core/events:zone.didUpdate</code> can be used to listen to the event.
	*
	* @tapestrydoc
	* @see AjaxFormLoop
	* @see FormFragment
	*/
	@SupportsInformalParameters
	@Import(module = "t5/core/zone")
	public class Zone implements ClientBodyElement
	{
	/**
	* Name of a function on the client-side Tapestry.ElementEffect object that is invoked to make the Zone's
	* <div> visible before being updated. If not specified, then the basic "show" method is used.
	*
	* @deprecated In 5.4, with no specific replacement, now does nothing (see notes on client-side JavaScript events, elsewhere)
	*/
	@Parameter(defaultPrefix = BindingConstants.LITERAL)
	private String show;

	/**
	* Name of a function on the client-side Tapestry.ElementEffect object that is invoked after the Zone's content has
	* been updated. If not specified, then the basic "highlight" method is used, which performs a classic "yellow fade"
	* to indicate to the user that and update has taken place.
	*
	* @deprecated In 5.4, with no specific replacement, now does nothing (see notes on client-side JavaScript events, elsewhere)
	*/
	@Parameter(defaultPrefix = BindingConstants.LITERAL)
	private String update;

	/**
	* The element name to render for the zone; this defaults to the element actually used in the template, or "div" if
	* no specific element was specified.
	*/
	@Parameter(required = true, allowNull = false, defaultPrefix = BindingConstants.LITERAL)
	private String elementName;

	/**
	* If bound, then the id attribute of the rendered element will be this exact value. If not bound, then a unique id
	* is generated for the element.
	*/
	@Parameter(name = "id", defaultPrefix = BindingConstants.LITERAL)
	private String idParameter;

	@Environmental
	private JavaScriptSupport javascriptSupport;

	@Inject
	private Environment environment;

	/**
	* In prior releases, this parameter could be overridden to false to force the outer element of the rendered
	* Zone to be non-visible. This behavior is no longer supported.
	*
	* @deprecated Deprecated in 5.4 with no replacement.
	*/
	@Parameter
	private boolean visible;

	/**
	* if set to true, then Ajax updates related to this Zone will, when rending, use simple IDs (not namespaced ids).
	* This is useful when the Zone contains a simple Form, as it (hopefully) ensures that the same ids used when
	* initially rendering, and when processing the submission, are also used when re-rendering the Form (to present
	* errors to the user). The default is false, maintaining the same behavior as in Tapestry 5.3 and earlier.
	*
	* @since 5.4
	*/
	@Parameter
	private boolean simpleIds;

	@Inject
	private ComponentResources resources;

	@Inject
	private Heartbeat heartbeat;

	@Inject
	private Logger logger;

	@Inject
	private ClientDataEncoder clientDataEncoder;

	@Inject
	private HiddenFieldLocationRules rules;

	private String clientId;

	private boolean insideForm;

	private HiddenFieldPositioner hiddenFieldPositioner;

	private ComponentActionSink actionSink;

	@Environmental(false)
	private FormSupport formSupport;

	@Inject
	private DeprecationWarning deprecationWarning;

	@Inject
	@Symbol(SymbolConstants.COMPACT_JSON)
	private boolean compactJSON;

	String defaultElementName()
	{
	return resources.getElementName("div");
	}

	void pageLoaded()
	{
	deprecationWarning.ignoredComponentParameters(resources, "show", "update", "visible");
	}

	void beginRender(MarkupWriter writer)
	{
	clientId = resources.isBound("id") ? idParameter : javascriptSupport.allocateClientId(resources);

	Element e = writer.element(elementName,
	"id", clientId,
	"data-container-type", "zone");

	if (simpleIds)
	{
	e.attribute("data-simple-ids", "true");
	}

	resources.renderInformalParameters(writer);

	insideForm = formSupport != null;

	if (insideForm)
	{
	JSONObject parameters = new JSONObject(RequestConstants.FORM_CLIENTID_PARAMETER, formSupport.getClientId(),
	RequestConstants.FORM_COMPONENTID_PARAMETER, formSupport.getFormComponentId());

	e.attribute("data-zone-parameters",
	parameters.toString(compactJSON));

	hiddenFieldPositioner = new HiddenFieldPositioner(writer, rules);

	actionSink = new ComponentActionSink(logger, clientDataEncoder);

	environment.push(FormSupport.class, new FormSupportAdapter(formSupport)
	{
	@Override
	public <T> void store(T component, ComponentAction<T> action)
	{
	actionSink.store(component, action);
	}

	@Override
	public <T> void storeCancel(T component, ComponentAction<T> action)
	{
	actionSink.storeCancel(component, action);
	}

	@Override
	public <T> void storeAndExecute(T component, ComponentAction<T> action)
	{
	store(component, action);

	action.execute(component);
	}

	});
	}

	heartbeat.begin();
	}

	void afterRender(MarkupWriter writer)
	{
	heartbeat.end();

	if (insideForm)
	{
	environment.pop(FormSupport.class);

	if (actionSink.isEmpty())
	{
	hiddenFieldPositioner.discard();
	} else
	{
	hiddenFieldPositioner.getElement().attributes("type", "hidden",

	"name", Form.FORM_DATA,

	"value", actionSink.getClientData());
	}
	}

	writer.end(); // div
	}

	/**
	* The client id of the Zone; this is set when the Zone renders and will either be the value bound to the id
	* parameter, or an allocated unique id. When the id parameter is bound, this value is always accurate.
	* When the id parameter is not bound, the clientId is set during the {@linkplain BeginRender begin render phase}
	* and will be null or inaccurate before then.
	*
	* @return client-side element id
	*/
	public String getClientId()
	{
	if (resources.isBound("id"))
	return idParameter;

	// TAP4-2342. I know this won't work with a Zone with no given clientId and that was already
	// via AJAX inside an outer Zone, but it's still better than nothing.
	if (clientId == null)
	{
	clientId = resources.getId();
	}

	return clientId;
	}

	/**
	* Returns the zone's body (the content enclosed by its start and end tags). This is often used as part of an Ajax
	* partial page render to update the client with a fresh render of the content inside the zone.
	*
	* @return the zone's body as a Block
	*/
	public Block getBody()
	{
	return resources.getBody();
	}
	}