// 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.
* <p/>
* 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.
* <p/>
* 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.
* <p/>
* 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.
* <p/>
* 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.
* <p/>
* A Zone starts and stops a {@link Heartbeat} when it renders (both normally, and when re-rendering).
* <p/>
* 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();
}
}