tapestry-core/src/main/java/org/apache/tapestry5/internal/services/DocumentLinkerImpl.java - tapestry-5 - Git at Google

 // Copyright 2007-2013 The Apache Software Foundation
 //
 // 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.internal.services;

 import org.apache.tapestry5.dom.Document;
 import org.apache.tapestry5.dom.Element;
 import org.apache.tapestry5.dom.Node;
 import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
 import org.apache.tapestry5.json.JSONArray;
 import org.apache.tapestry5.services.javascript.InitializationPriority;
 import org.apache.tapestry5.services.javascript.ModuleConfigurationCallback;
 import org.apache.tapestry5.services.javascript.ModuleManager;
 import org.apache.tapestry5.services.javascript.StylesheetLink;

 import java.util.List;

 public class DocumentLinkerImpl implements DocumentLinker
 {
     private final List<String> coreLibraryURLs = CollectionFactory.newList();

     private final List<String> libraryURLs = CollectionFactory.newList();

     private final ModuleInitsManager initsManager = new ModuleInitsManager();

     private final List<ModuleConfigurationCallback> moduleConfigurationCallbacks = CollectionFactory.newList();

     private final List<StylesheetLink> includedStylesheets = CollectionFactory.newList();

     private final ModuleManager moduleManager;

     private final boolean omitGeneratorMetaTag;

     private final String tapestryBanner;

     // Initially false; set to true when a scriptURL or any kind of initialization is added.
     private boolean hasScriptsOrInitializations;

     /**
      * @param moduleManager
      *         used to identify the root folder for dynamically loaded modules
      * @param omitGeneratorMetaTag
      *         via symbol configuration
      * @param tapestryVersion
      *         version of Tapestry framework (for meta tag)
      */
     public DocumentLinkerImpl(ModuleManager moduleManager, boolean omitGeneratorMetaTag, String tapestryVersion)
     {
         this.moduleManager = moduleManager;
         this.omitGeneratorMetaTag = omitGeneratorMetaTag;

         tapestryBanner = String.format("Apache Tapestry Framework (version %s)", tapestryVersion);
     }

     public void addStylesheetLink(StylesheetLink sheet)
     {
         includedStylesheets.add(sheet);
     }


     public void addCoreLibrary(String libraryURL)
     {
         coreLibraryURLs.add(libraryURL);

         hasScriptsOrInitializations = true;
     }

     public void addLibrary(String libraryURL)
     {
         libraryURLs.add(libraryURL);

         hasScriptsOrInitializations = true;
     }

     public void addScript(InitializationPriority priority, String script)
     {
         addInitialization(priority, "t5/core/pageinit", "evalJavaScript", new JSONArray().put(script));
     }

     public void addInitialization(InitializationPriority priority, String moduleName, String functionName, JSONArray arguments)
     {
         initsManager.addInitialization(priority, moduleName, functionName, arguments);

         hasScriptsOrInitializations = true;
     }

     /**
      * Updates the supplied Document, possibly adding &lt;head&gt; or &lt;body&gt; elements.
      *
      * @param document
      *         to be updated
      */
     public void updateDocument(Document document)
     {
         Element root = document.getRootElement();

         // If the document failed to render at all, that's a different problem and is reported elsewhere.

         if (root == null)
         {
             return;
         }

         addStylesheetsToHead(root, includedStylesheets);

         // only add the generator meta only to html documents

         boolean isHtmlRoot = root.getName().equals("html");

         if (!omitGeneratorMetaTag && isHtmlRoot)
         {
             Element head = findOrCreateElement(root, "head", true);

             Element existingMeta = head.find("meta");

             addElementBefore(head, existingMeta, "meta", "name", "generator", "content", tapestryBanner);
         }

         addScriptElements(root);
     }

     private static Element addElementBefore(Element container, Element insertionPoint, String name, String... namesAndValues)
     {
         if (insertionPoint == null)
         {
             return container.element(name, namesAndValues);
         }

         return insertionPoint.elementBefore(name, namesAndValues);
     }


     private void addScriptElements(Element root)
     {
         String rootElementName = root.getName();

         Element body = rootElementName.equals("html") ? findOrCreateElement(root, "body", false) : null;

         // Write the data-page-initialized attribute in for all pages; it will be "true" when the page has no
         // initializations (which is somewhat rare in Tapestry). When the page has initializations, it will be set to
         // "true" once those initializations all run.
         if (body != null)
         {
             body.attribute("data-page-initialized", Boolean.toString(!hasScriptsOrInitializations));
         }

         if (!hasScriptsOrInitializations)
         {
             return;
         }

         // This only applies when the document is an HTML document. This may need to change in the
         // future, perhaps configurable, to allow for html and xhtml and perhaps others. Does SVG
         // use stylesheets?

         if (!rootElementName.equals("html"))
         {
             throw new RuntimeException(String.format("The root element of the rendered document was <%s>, not <html>. A root element of <html> is needed when linking JavaScript and stylesheet resources.", rootElementName));
         }

         // TAPESTRY-2364

         addScriptsToEndOfBody(body);
     }

     /**
      * Finds an element by name, or creates it. Returns the element (if found), or creates a new element
      * with the given name, and returns it. The new element will be positioned at the top or bottom of the root element.
      *
      * @param root
      *         element to search
      * @param childElement
      *         element name of child
      * @param atTop
      *         if not found, create new element at top of root, or at bottom
      * @return the located element, or null
      */
     private Element findOrCreateElement(Element root, String childElement, boolean atTop)
     {
         Element container = root.find(childElement);

         // Create the element is it is missing.

         if (container == null)
         {
             container = atTop ? root.elementAt(0, childElement) : root.element(childElement);
         }

         return container;
     }


     /**
      * Adds {@code <script>} elements for the RequireJS library, then any statically includes JavaScript libraries
      * (including JavaScript stack virtual assets), then the initialization script block.
      *
      * @param body
      *         element to add the dynamic scripting to
      */
     protected void addScriptsToEndOfBody(Element body)
     {
         moduleManager.writeConfiguration(body, moduleConfigurationCallbacks);

         // Write the core libraries, which includes RequireJS:

         for (String url : coreLibraryURLs)
         {
             body.element("script",
                     "type", "text/javascript",
                     "src", url);
         }

         // Write the initialization at this point.

         moduleManager.writeInitialization(body, libraryURLs, initsManager.getSortedInits());
     }

     private static Element createTemporaryContainer(Element headElement, String existingElementName, String otherExistingElement, String newElementName)
     {
         Element existingElement = headElement.find(existingElementName);
         Element otherElement = headElement.find(otherExistingElement);
         Element element = null;

         if (existingElement != null && otherElement != null) {

             // figure out what comes first.
             for (Node node : headElement.getChildren()) {
                 if (existingElement == node) {
                     element = existingElement;
                     break;
                 }
                 else if (otherElement == node) {
                     element = otherElement;
                     break;
                 }
             }

         }
         else if (existingElement != null) {
             element = existingElement;
         }
         else {
             element = otherElement;
         }

         // Create temporary container for the new <script> elements
         return addElementBefore(headElement, element, newElementName);

     }

     /**
      * Locates the head element under the root ("html") element, creating it if necessary, and adds the stylesheets to
      * it.
      *
      * @param root
      *         element of document
      * @param stylesheets
      *         to add to the document
      */
     protected void addStylesheetsToHead(Element root, List<StylesheetLink> stylesheets)
     {
         int count = stylesheets.size();

         if (count == 0)
         {
             return;
         }

         // This only applies when the document is an HTML document. This may need to change in the
         // future, perhaps configurable, to allow for html and xhtml and perhaps others. Does SVG
         // use stylesheets?

         String rootElementName = root.getName();

         // Not an html document, don't add anything.
         if (!rootElementName.equals("html"))
         {
             return;
         }

         Element head = findOrCreateElement(root, "head", true);

         // Create a temporary container element.
         Element container = createTemporaryContainer(head, "style", "link", "stylesheet-container");

         for (int i = 0; i < count; i++)
         {
             stylesheets.get(i).add(container);
         }

         container.pop();
     }

     public void addModuleConfigurationCallback(ModuleConfigurationCallback callback)
     {
         assert callback != null;
         moduleConfigurationCallbacks.add(callback);
     }

 }
	// Copyright 2007-2013 The Apache Software Foundation
	//
	// 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.internal.services;

	import org.apache.tapestry5.dom.Document;
	import org.apache.tapestry5.dom.Element;
	import org.apache.tapestry5.dom.Node;
	import org.apache.tapestry5.ioc.internal.util.CollectionFactory;
	import org.apache.tapestry5.json.JSONArray;
	import org.apache.tapestry5.services.javascript.InitializationPriority;
	import org.apache.tapestry5.services.javascript.ModuleConfigurationCallback;
	import org.apache.tapestry5.services.javascript.ModuleManager;
	import org.apache.tapestry5.services.javascript.StylesheetLink;

	import java.util.List;

	public class DocumentLinkerImpl implements DocumentLinker
	{
	private final List<String> coreLibraryURLs = CollectionFactory.newList();

	private final List<String> libraryURLs = CollectionFactory.newList();

	private final ModuleInitsManager initsManager = new ModuleInitsManager();

	private final List<ModuleConfigurationCallback> moduleConfigurationCallbacks = CollectionFactory.newList();

	private final List<StylesheetLink> includedStylesheets = CollectionFactory.newList();

	private final ModuleManager moduleManager;

	private final boolean omitGeneratorMetaTag;

	private final String tapestryBanner;

	// Initially false; set to true when a scriptURL or any kind of initialization is added.
	private boolean hasScriptsOrInitializations;

	/**
	* @param moduleManager
	* used to identify the root folder for dynamically loaded modules
	* @param omitGeneratorMetaTag
	* via symbol configuration
	* @param tapestryVersion
	* version of Tapestry framework (for meta tag)
	*/
	public DocumentLinkerImpl(ModuleManager moduleManager, boolean omitGeneratorMetaTag, String tapestryVersion)
	{
	this.moduleManager = moduleManager;
	this.omitGeneratorMetaTag = omitGeneratorMetaTag;

	tapestryBanner = String.format("Apache Tapestry Framework (version %s)", tapestryVersion);
	}

	public void addStylesheetLink(StylesheetLink sheet)
	{
	includedStylesheets.add(sheet);
	}


	public void addCoreLibrary(String libraryURL)
	{
	coreLibraryURLs.add(libraryURL);

	hasScriptsOrInitializations = true;
	}

	public void addLibrary(String libraryURL)
	{
	libraryURLs.add(libraryURL);

	hasScriptsOrInitializations = true;
	}

	public void addScript(InitializationPriority priority, String script)
	{
	addInitialization(priority, "t5/core/pageinit", "evalJavaScript", new JSONArray().put(script));
	}

	public void addInitialization(InitializationPriority priority, String moduleName, String functionName, JSONArray arguments)
	{
	initsManager.addInitialization(priority, moduleName, functionName, arguments);

	hasScriptsOrInitializations = true;
	}

	/**
	* Updates the supplied Document, possibly adding <head> or <body> elements.
	*
	* @param document
	* to be updated
	*/
	public void updateDocument(Document document)
	{
	Element root = document.getRootElement();

	// If the document failed to render at all, that's a different problem and is reported elsewhere.

	if (root == null)
	{
	return;
	}

	addStylesheetsToHead(root, includedStylesheets);

	// only add the generator meta only to html documents

	boolean isHtmlRoot = root.getName().equals("html");

	if (!omitGeneratorMetaTag && isHtmlRoot)
	{
	Element head = findOrCreateElement(root, "head", true);

	Element existingMeta = head.find("meta");

	addElementBefore(head, existingMeta, "meta", "name", "generator", "content", tapestryBanner);
	}

	addScriptElements(root);
	}

	private static Element addElementBefore(Element container, Element insertionPoint, String name, String... namesAndValues)
	{
	if (insertionPoint == null)
	{
	return container.element(name, namesAndValues);
	}

	return insertionPoint.elementBefore(name, namesAndValues);
	}


	private void addScriptElements(Element root)
	{
	String rootElementName = root.getName();

	Element body = rootElementName.equals("html") ? findOrCreateElement(root, "body", false) : null;

	// Write the data-page-initialized attribute in for all pages; it will be "true" when the page has no
	// initializations (which is somewhat rare in Tapestry). When the page has initializations, it will be set to
	// "true" once those initializations all run.
	if (body != null)
	{
	body.attribute("data-page-initialized", Boolean.toString(!hasScriptsOrInitializations));
	}

	if (!hasScriptsOrInitializations)
	{
	return;
	}

	// This only applies when the document is an HTML document. This may need to change in the
	// future, perhaps configurable, to allow for html and xhtml and perhaps others. Does SVG
	// use stylesheets?

	if (!rootElementName.equals("html"))
	{
	throw new RuntimeException(String.format("The root element of the rendered document was <%s>, not <html>. A root element of <html> is needed when linking JavaScript and stylesheet resources.", rootElementName));
	}

	// TAPESTRY-2364

	addScriptsToEndOfBody(body);
	}

	/**
	* Finds an element by name, or creates it. Returns the element (if found), or creates a new element
	* with the given name, and returns it. The new element will be positioned at the top or bottom of the root element.
	*
	* @param root
	* element to search
	* @param childElement
	* element name of child
	* @param atTop
	* if not found, create new element at top of root, or at bottom
	* @return the located element, or null
	*/
	private Element findOrCreateElement(Element root, String childElement, boolean atTop)
	{
	Element container = root.find(childElement);

	// Create the element is it is missing.

	if (container == null)
	{
	container = atTop ? root.elementAt(0, childElement) : root.element(childElement);
	}

	return container;
	}


	/**
	* Adds {@code <script>} elements for the RequireJS library, then any statically includes JavaScript libraries
	* (including JavaScript stack virtual assets), then the initialization script block.
	*
	* @param body
	* element to add the dynamic scripting to
	*/
	protected void addScriptsToEndOfBody(Element body)
	{
	moduleManager.writeConfiguration(body, moduleConfigurationCallbacks);

	// Write the core libraries, which includes RequireJS:

	for (String url : coreLibraryURLs)
	{
	body.element("script",
	"type", "text/javascript",
	"src", url);
	}

	// Write the initialization at this point.

	moduleManager.writeInitialization(body, libraryURLs, initsManager.getSortedInits());
	}

	private static Element createTemporaryContainer(Element headElement, String existingElementName, String otherExistingElement, String newElementName)
	{
	Element existingElement = headElement.find(existingElementName);
	Element otherElement = headElement.find(otherExistingElement);
	Element element = null;

	if (existingElement != null && otherElement != null) {

	// figure out what comes first.
	for (Node node : headElement.getChildren()) {
	if (existingElement == node) {
	element = existingElement;
	break;
	}
	else if (otherElement == node) {
	element = otherElement;
	break;
	}
	}

	}
	else if (existingElement != null) {
	element = existingElement;
	}
	else {
	element = otherElement;
	}

	// Create temporary container for the new <script> elements
	return addElementBefore(headElement, element, newElementName);

	}

	/**
	* Locates the head element under the root ("html") element, creating it if necessary, and adds the stylesheets to
	* it.
	*
	* @param root
	* element of document
	* @param stylesheets
	* to add to the document
	*/
	protected void addStylesheetsToHead(Element root, List<StylesheetLink> stylesheets)
	{
	int count = stylesheets.size();

	if (count == 0)
	{
	return;
	}

	// This only applies when the document is an HTML document. This may need to change in the
	// future, perhaps configurable, to allow for html and xhtml and perhaps others. Does SVG
	// use stylesheets?

	String rootElementName = root.getName();

	// Not an html document, don't add anything.
	if (!rootElementName.equals("html"))
	{
	return;
	}

	Element head = findOrCreateElement(root, "head", true);

	// Create a temporary container element.
	Element container = createTemporaryContainer(head, "style", "link", "stylesheet-container");

	for (int i = 0; i < count; i++)
	{
	stylesheets.get(i).add(container);
	}

	container.pop();
	}

	public void addModuleConfigurationCallback(ModuleConfigurationCallback callback)
	{
	assert callback != null;
	moduleConfigurationCallbacks.add(callback);
	}

	}