tapestry-core/src/main/java/org/apache/tapestry5/corelib/components/AjaxFormLoop.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.AjaxFormLoopContext;
 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.services.TypeCoercer;
 import org.apache.tapestry5.json.JSONObject;
 import org.apache.tapestry5.services.*;
 import org.apache.tapestry5.services.ajax.AjaxResponseRenderer;
 import org.apache.tapestry5.services.compatibility.DeprecationWarning;
 import org.apache.tapestry5.services.javascript.JavaScriptSupport;

 import java.util.Collections;
 import java.util.Iterator;

 /**
  * A special form of the {@link org.apache.tapestry5.corelib.components.Loop}
  * component that adds Ajax support to handle adding new rows and removing
  * existing rows dynamically.
  *
  * This component expects that the values being iterated over are entities that
  * can be identified via a {@link org.apache.tapestry5.ValueEncoder}, therefore
  * you must either bind the "encoder" parameter to a ValueEncoder or use an
  * entity type for the "value" parameter for which Tapestry can provide a
  * ValueEncoder automatically.
  *
  * Works with {@link org.apache.tapestry5.corelib.components.AddRowLink} and
  * {@link org.apache.tapestry5.corelib.components.RemoveRowLink} components.
  *
  * The addRow event will receive the context specified by the context parameter.
  *
  * The removeRow event will receive the client-side value for the row being iterated.
  *
  * @tapestrydoc
  * @see EventConstants#ADD_ROW
  * @see EventConstants#REMOVE_ROW
  * @see AddRowLink
  * @see RemoveRowLink
  * @see Loop
  */
 @Events(
         {EventConstants.ADD_ROW, EventConstants.REMOVE_ROW})
 @Import(module = "t5/core/ajaxformloop")
 @SupportsInformalParameters
 public class AjaxFormLoop
 {
     /**
      * The element to render for each iteration of the loop. The default comes from the template, or "div" if the
      * template did not specify an element.
      */
     @Parameter(defaultPrefix = BindingConstants.LITERAL)
     @Property(write = false)
     private String element;

     /**
      * The objects to iterate over (passed to the internal Loop component).
      */
     @Parameter(required = true, autoconnect = true)
     private Iterable source;

     /**
      * The current value from the source.
      */
     @Parameter(required = true)
     private Object value;

     /**
      * Name of a function on the client-side Tapestry.ElementEffect object that is invoked to make added content
      * visible. This was used by the FormInjector component (remove in 5.4), when adding a new row to the loop. Leaving as
      * null uses the default function, "highlight".
      *
      * @deprecated Deprecated in 5.4 with no replacement.
      */
     @Parameter(defaultPrefix = BindingConstants.LITERAL)
     private String show;

     /**
      * The context for the form loop (optional parameter). This list of values will be converted into strings and
      * included in the URI. The strings will be coerced back to whatever their values are and made available to event
      * handler methods. Note that the context is only encoded and available to the {@linkplain EventConstants#ADD_ROW addRow}
      * event; for the {@linkplain EventConstants#REMOVE_ROW} event, the context passed to event handlers
      * is simply the decoded value for the row that is to be removed.
      */
     @Parameter
     private Object[] context;

     /**
      * A block to render after the loo
      * This typically contains a {@link org.apache.tapestry5.corelib.components.AddRowLink}.
      */
     @Parameter(value = "block:defaultAddRow", defaultPrefix = BindingConstants.LITERAL)
     @Property(write = false)
     private Block addRow;

     /**
      * The block that contains the form injector (it is rendered last, as the "tail" of the AjaxFormLoop). This, in
      * turn, references the addRow block (from a parameter, or a default).
      */
     @Inject
     private Block tail;

     /**
      * A ValueEncoder used to convert server-side objects (provided by the
      * "source" parameter) into unique client-side strings (typically IDs) and
      * back. Note: this parameter may be OMITTED if Tapestry is configured to
      * provide a ValueEncoder automatically for the type of property bound to
      * the "value" parameter.
      */
     @Parameter(required = true, allowNull = false)
     private ValueEncoder<Object> encoder;

     @InjectComponent
     private FormFragment fragment;

     @Inject
     private Block ajaxResponse;

     @Inject
     private ComponentResources resources;

     @Environmental
     private FormSupport formSupport;

     @Environmental
     private Heartbeat heartbeat;

     @Inject
     private Environment environment;

     @Inject
     private JavaScriptSupport jsSupport;

     private Iterator iterator;

     private Element wrapper;

     @Inject
     private TypeCoercer typeCoercer;

     @Inject
     private ComponentDefaultProvider defaultProvider;

     @Inject
     private AjaxResponseRenderer ajaxResponseRenderer;

     @Inject
     private DeprecationWarning deprecationWarning;

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

     ValueEncoder defaultEncoder()
     {
         return defaultProvider.defaultValueEncoder("value", resources);
     }

     private final AjaxFormLoopContext formLoopContext = new AjaxFormLoopContext()
     {
         public String encodedRowValue()
         {
             return encoder.toClient(value);
         }
     };

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

     /**
      * Action for synchronizing the current element of the loop by recording its client value.
      */
     static class SyncValue implements ComponentAction<AjaxFormLoop>
     {
         private final String clientValue;

         public SyncValue(String clientValue)
         {
             this.clientValue = clientValue;
         }

         public void execute(AjaxFormLoop component)
         {
             component.syncValue(clientValue);
         }

         @Override
         public String toString()
         {
             return String.format("AjaxFormLoop.SyncValue[%s]", clientValue);
         }
     }

     private static final ComponentAction<AjaxFormLoop> BEGIN_HEARTBEAT = new ComponentAction<AjaxFormLoop>()
     {
         public void execute(AjaxFormLoop component)
         {
             component.beginHeartbeat();
         }

         @Override
         public String toString()
         {
             return "AjaxFormLoop.BeginHeartbeat";
         }
     };

     @Property(write = false)
     private final Renderable beginHeartbeat = new Renderable()
     {
         public void render(MarkupWriter writer)
         {
             formSupport.storeAndExecute(AjaxFormLoop.this, BEGIN_HEARTBEAT);
         }
     };

     private static final ComponentAction<AjaxFormLoop> END_HEARTBEAT = new ComponentAction<AjaxFormLoop>()
     {
         public void execute(AjaxFormLoop component)
         {
             component.endHeartbeat();
         }

         @Override
         public String toString()
         {
             return "AjaxFormLoop.EndHeartbeat";
         }
     };

     @Property(write = false)
     private final Renderable endHeartbeat = new Renderable()
     {
         public void render(MarkupWriter writer)
         {
             formSupport.storeAndExecute(AjaxFormLoop.this, END_HEARTBEAT);
         }
     };

     @Property(write = false)
     private final Renderable beforeBody = new Renderable()
     {
         public void render(MarkupWriter writer)
         {
             beginHeartbeat();
             syncCurrentValue();
         }
     };

     @Property(write = false)
     private final Renderable afterBody = new Renderable()
     {
         public void render(MarkupWriter writer)
         {
             endHeartbeat();
         }
     };

     @SuppressWarnings(
             {"unchecked"})
     private void syncValue(String clientValue)
     {
         Object value = encoder.toValue(clientValue);

         if (value == null)
             throw new RuntimeException(String.format(
                     "Unable to convert client value '%s' back into a server-side object.", clientValue));

         this.value = value;
     }

     @Property(write = false)
     private final Renderable syncValue = new Renderable()
     {
         public void render(MarkupWriter writer)
         {
             syncCurrentValue();
         }
     };

     private void syncCurrentValue()
     {
         String id = toClientValue();

         // Add the command that restores value from the value clientValue,
         // when the form is submitted.

         formSupport.store(this, new SyncValue(id));
     }

     /**
      * Uses the {@link org.apache.tapestry5.ValueEncoder} to convert the current server-side value to a client-side
      * value.
      */
     @SuppressWarnings(
             {"unchecked"})
     private String toClientValue()
     {
         return encoder.toClient(value);
     }

     void setupRender(MarkupWriter writer)
     {
         pushContext();

         iterator = source == null ? Collections.EMPTY_LIST.iterator() : source.iterator();

         Link removeRowLink = resources.createEventLink("triggerRemoveRow", context);
         Link injectRowLink = resources.createEventLink("injectRow", context);

         injectRowLink.addParameter(RequestConstants.FORM_CLIENTID_PARAMETER, formSupport.getClientId());
         injectRowLink.addParameter(RequestConstants.FORM_COMPONENTID_PARAMETER, formSupport.getFormComponentId());

         // Fix for TAP5-227 - AjaxFormLoop dont work well inside a table tag
         Element element = writer.getElement();
         this.wrapper = element.getAttribute("data-container-type") != null
                 || element.getAttribute("data-remove-row-url") != null
                 || element.getAttribute("data-inject-row-url") != null ? writer.element("div") : null;

         writer.attributes("data-container-type", "core/AjaxFormLoop",
                 "data-remove-row-url", removeRowLink,
                 "data-inject-row-url", injectRowLink);
     }

     private void pushContext()
     {
         environment.push(AjaxFormLoopContext.class, formLoopContext);
     }

     boolean beginRender(MarkupWriter writer)
     {
         if (!iterator.hasNext())
         {
             return false;
         }

         value = iterator.next();

         // Return true: render the body for this value; that ends up being a form-fragment.

         return true;
     }

     Object afterRender(MarkupWriter writer)
     {
         // When out of source items to render, switch over to the addRow block (either the default,
         // or from the addRow parameter) before proceeding to cleanup render.

         if (!iterator.hasNext())
         {
             return tail;
         }

         // There's more to come, loop back to begin render.

         return false;
     }

     // Capture BeginRender event from the formfragment or the addRowWrapper, and render the informal parameters
     // into the row.
     boolean onBeginRender(MarkupWriter writer)
     {
         resources.renderInformalParameters(writer);

         return true;
     }

     void cleanupRender(MarkupWriter writer)
     {
         if (wrapper != null)
             writer.end();

         popContext();
     }

     private void popContext()
     {
         environment.pop(AjaxFormLoopContext.class);
     }

     Object onInjectRow(EventContext context)
     {
         ComponentEventCallback callback = new ComponentEventCallback()
         {
             public boolean handleResult(Object result)
             {
                 value = result;

                 return true;
             }
         };

         resources.triggerContextEvent(EventConstants.ADD_ROW, context, callback);

         if (value == null)
             throw new IllegalArgumentException(String.format(
                     "Event handler for event 'addRow' from %s should have returned a non-null value.",
                     resources.getCompleteId()));

         ajaxResponseRenderer.addFilter(new PartialMarkupRendererFilter()
         {
             public void renderMarkup(MarkupWriter writer, JSONObject reply, PartialMarkupRenderer renderer)
             {
                 pushContext();

                 renderer.renderMarkup(writer, reply);

                 popContext();
             }
         });

         return ajaxResponse;
     }

     Object onTriggerRemoveRow(@RequestParameter("t:rowvalue") String encodedValue)
     {
         syncValue(encodedValue);

         resources.triggerEvent(EventConstants.REMOVE_ROW, new Object[]
                 {value}, null);

         return new JSONObject();
     }

     private void beginHeartbeat()
     {
         heartbeat.begin();
     }

     private void endHeartbeat()
     {
         heartbeat.end();
     }
 }
	// 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.AjaxFormLoopContext;
	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.services.TypeCoercer;
	import org.apache.tapestry5.json.JSONObject;
	import org.apache.tapestry5.services.*;
	import org.apache.tapestry5.services.ajax.AjaxResponseRenderer;
	import org.apache.tapestry5.services.compatibility.DeprecationWarning;
	import org.apache.tapestry5.services.javascript.JavaScriptSupport;

	import java.util.Collections;
	import java.util.Iterator;

	/**
	* A special form of the {@link org.apache.tapestry5.corelib.components.Loop}
	* component that adds Ajax support to handle adding new rows and removing
	* existing rows dynamically.
	*
	* This component expects that the values being iterated over are entities that
	* can be identified via a {@link org.apache.tapestry5.ValueEncoder}, therefore
	* you must either bind the "encoder" parameter to a ValueEncoder or use an
	* entity type for the "value" parameter for which Tapestry can provide a
	* ValueEncoder automatically.
	*
	* Works with {@link org.apache.tapestry5.corelib.components.AddRowLink} and
	* {@link org.apache.tapestry5.corelib.components.RemoveRowLink} components.
	*
	* The addRow event will receive the context specified by the context parameter.
	*
	* The removeRow event will receive the client-side value for the row being iterated.
	*
	* @tapestrydoc
	* @see EventConstants#ADD_ROW
	* @see EventConstants#REMOVE_ROW
	* @see AddRowLink
	* @see RemoveRowLink
	* @see Loop
	*/
	@Events(
	{EventConstants.ADD_ROW, EventConstants.REMOVE_ROW})
	@Import(module = "t5/core/ajaxformloop")
	@SupportsInformalParameters
	public class AjaxFormLoop
	{
	/**
	* The element to render for each iteration of the loop. The default comes from the template, or "div" if the
	* template did not specify an element.
	*/
	@Parameter(defaultPrefix = BindingConstants.LITERAL)
	@Property(write = false)
	private String element;

	/**
	* The objects to iterate over (passed to the internal Loop component).
	*/
	@Parameter(required = true, autoconnect = true)
	private Iterable source;

	/**
	* The current value from the source.
	*/
	@Parameter(required = true)
	private Object value;

	/**
	* Name of a function on the client-side Tapestry.ElementEffect object that is invoked to make added content
	* visible. This was used by the FormInjector component (remove in 5.4), when adding a new row to the loop. Leaving as
	* null uses the default function, "highlight".
	*
	* @deprecated Deprecated in 5.4 with no replacement.
	*/
	@Parameter(defaultPrefix = BindingConstants.LITERAL)
	private String show;

	/**
	* The context for the form loop (optional parameter). This list of values will be converted into strings and
	* included in the URI. The strings will be coerced back to whatever their values are and made available to event
	* handler methods. Note that the context is only encoded and available to the {@linkplain EventConstants#ADD_ROW addRow}
	* event; for the {@linkplain EventConstants#REMOVE_ROW} event, the context passed to event handlers
	* is simply the decoded value for the row that is to be removed.
	*/
	@Parameter
	private Object[] context;

	/**
	* A block to render after the loo
	* This typically contains a {@link org.apache.tapestry5.corelib.components.AddRowLink}.
	*/
	@Parameter(value = "block:defaultAddRow", defaultPrefix = BindingConstants.LITERAL)
	@Property(write = false)
	private Block addRow;

	/**
	* The block that contains the form injector (it is rendered last, as the "tail" of the AjaxFormLoop). This, in
	* turn, references the addRow block (from a parameter, or a default).
	*/
	@Inject
	private Block tail;

	/**
	* A ValueEncoder used to convert server-side objects (provided by the
	* "source" parameter) into unique client-side strings (typically IDs) and
	* back. Note: this parameter may be OMITTED if Tapestry is configured to
	* provide a ValueEncoder automatically for the type of property bound to
	* the "value" parameter.
	*/
	@Parameter(required = true, allowNull = false)
	private ValueEncoder<Object> encoder;

	@InjectComponent
	private FormFragment fragment;

	@Inject
	private Block ajaxResponse;

	@Inject
	private ComponentResources resources;

	@Environmental
	private FormSupport formSupport;

	@Environmental
	private Heartbeat heartbeat;

	@Inject
	private Environment environment;

	@Inject
	private JavaScriptSupport jsSupport;

	private Iterator iterator;

	private Element wrapper;

	@Inject
	private TypeCoercer typeCoercer;

	@Inject
	private ComponentDefaultProvider defaultProvider;

	@Inject
	private AjaxResponseRenderer ajaxResponseRenderer;

	@Inject
	private DeprecationWarning deprecationWarning;

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

	ValueEncoder defaultEncoder()
	{
	return defaultProvider.defaultValueEncoder("value", resources);
	}

	private final AjaxFormLoopContext formLoopContext = new AjaxFormLoopContext()
	{
	public String encodedRowValue()
	{
	return encoder.toClient(value);
	}
	};

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

	/**
	* Action for synchronizing the current element of the loop by recording its client value.
	*/
	static class SyncValue implements ComponentAction<AjaxFormLoop>
	{
	private final String clientValue;

	public SyncValue(String clientValue)
	{
	this.clientValue = clientValue;
	}

	public void execute(AjaxFormLoop component)
	{
	component.syncValue(clientValue);
	}

	@Override
	public String toString()
	{
	return String.format("AjaxFormLoop.SyncValue[%s]", clientValue);
	}
	}

	private static final ComponentAction<AjaxFormLoop> BEGIN_HEARTBEAT = new ComponentAction<AjaxFormLoop>()
	{
	public void execute(AjaxFormLoop component)
	{
	component.beginHeartbeat();
	}

	@Override
	public String toString()
	{
	return "AjaxFormLoop.BeginHeartbeat";
	}
	};

	@Property(write = false)
	private final Renderable beginHeartbeat = new Renderable()
	{
	public void render(MarkupWriter writer)
	{
	formSupport.storeAndExecute(AjaxFormLoop.this, BEGIN_HEARTBEAT);
	}
	};

	private static final ComponentAction<AjaxFormLoop> END_HEARTBEAT = new ComponentAction<AjaxFormLoop>()
	{
	public void execute(AjaxFormLoop component)
	{
	component.endHeartbeat();
	}

	@Override
	public String toString()
	{
	return "AjaxFormLoop.EndHeartbeat";
	}
	};

	@Property(write = false)
	private final Renderable endHeartbeat = new Renderable()
	{
	public void render(MarkupWriter writer)
	{
	formSupport.storeAndExecute(AjaxFormLoop.this, END_HEARTBEAT);
	}
	};

	@Property(write = false)
	private final Renderable beforeBody = new Renderable()
	{
	public void render(MarkupWriter writer)
	{
	beginHeartbeat();
	syncCurrentValue();
	}
	};

	@Property(write = false)
	private final Renderable afterBody = new Renderable()
	{
	public void render(MarkupWriter writer)
	{
	endHeartbeat();
	}
	};

	@SuppressWarnings(
	{"unchecked"})
	private void syncValue(String clientValue)
	{
	Object value = encoder.toValue(clientValue);

	if (value == null)
	throw new RuntimeException(String.format(
	"Unable to convert client value '%s' back into a server-side object.", clientValue));

	this.value = value;
	}

	@Property(write = false)
	private final Renderable syncValue = new Renderable()
	{
	public void render(MarkupWriter writer)
	{
	syncCurrentValue();
	}
	};

	private void syncCurrentValue()
	{
	String id = toClientValue();

	// Add the command that restores value from the value clientValue,
	// when the form is submitted.

	formSupport.store(this, new SyncValue(id));
	}

	/**
	* Uses the {@link org.apache.tapestry5.ValueEncoder} to convert the current server-side value to a client-side
	* value.
	*/
	@SuppressWarnings(
	{"unchecked"})
	private String toClientValue()
	{
	return encoder.toClient(value);
	}

	void setupRender(MarkupWriter writer)
	{
	pushContext();

	iterator = source == null ? Collections.EMPTY_LIST.iterator() : source.iterator();

	Link removeRowLink = resources.createEventLink("triggerRemoveRow", context);
	Link injectRowLink = resources.createEventLink("injectRow", context);

	injectRowLink.addParameter(RequestConstants.FORM_CLIENTID_PARAMETER, formSupport.getClientId());
	injectRowLink.addParameter(RequestConstants.FORM_COMPONENTID_PARAMETER, formSupport.getFormComponentId());

	// Fix for TAP5-227 - AjaxFormLoop dont work well inside a table tag
	Element element = writer.getElement();
	this.wrapper = element.getAttribute("data-container-type") != null
	\|\| element.getAttribute("data-remove-row-url") != null
	\|\| element.getAttribute("data-inject-row-url") != null ? writer.element("div") : null;

	writer.attributes("data-container-type", "core/AjaxFormLoop",
	"data-remove-row-url", removeRowLink,
	"data-inject-row-url", injectRowLink);
	}

	private void pushContext()
	{
	environment.push(AjaxFormLoopContext.class, formLoopContext);
	}

	boolean beginRender(MarkupWriter writer)
	{
	if (!iterator.hasNext())
	{
	return false;
	}

	value = iterator.next();

	// Return true: render the body for this value; that ends up being a form-fragment.

	return true;
	}

	Object afterRender(MarkupWriter writer)
	{
	// When out of source items to render, switch over to the addRow block (either the default,
	// or from the addRow parameter) before proceeding to cleanup render.

	if (!iterator.hasNext())
	{
	return tail;
	}

	// There's more to come, loop back to begin render.

	return false;
	}

	// Capture BeginRender event from the formfragment or the addRowWrapper, and render the informal parameters
	// into the row.
	boolean onBeginRender(MarkupWriter writer)
	{
	resources.renderInformalParameters(writer);

	return true;
	}

	void cleanupRender(MarkupWriter writer)
	{
	if (wrapper != null)
	writer.end();

	popContext();
	}

	private void popContext()
	{
	environment.pop(AjaxFormLoopContext.class);
	}

	Object onInjectRow(EventContext context)
	{
	ComponentEventCallback callback = new ComponentEventCallback()
	{
	public boolean handleResult(Object result)
	{
	value = result;

	return true;
	}
	};

	resources.triggerContextEvent(EventConstants.ADD_ROW, context, callback);

	if (value == null)
	throw new IllegalArgumentException(String.format(
	"Event handler for event 'addRow' from %s should have returned a non-null value.",
	resources.getCompleteId()));

	ajaxResponseRenderer.addFilter(new PartialMarkupRendererFilter()
	{
	public void renderMarkup(MarkupWriter writer, JSONObject reply, PartialMarkupRenderer renderer)
	{
	pushContext();

	renderer.renderMarkup(writer, reply);

	popContext();
	}
	});

	return ajaxResponse;
	}

	Object onTriggerRemoveRow(@RequestParameter("t:rowvalue") String encodedValue)
	{
	syncValue(encodedValue);

	resources.triggerEvent(EventConstants.REMOVE_ROW, new Object[]
	{value}, null);

	return new JSONObject();
	}

	private void beginHeartbeat()
	{
	heartbeat.begin();
	}

	private void endHeartbeat()
	{
	heartbeat.end();
	}
	}