001// Copyright 2007-2013 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.services;
016
017import org.apache.tapestry5.json.JSONArray;
018import org.apache.tapestry5.services.javascript.InitializationPriority;
019import org.apache.tapestry5.services.javascript.ModuleConfigurationCallback;
020import org.apache.tapestry5.services.javascript.StylesheetLink;
021
022/**
023 * Responsible for injecting script and style links into the <head> and <body> element of the rendered HTML
024 * document.
025 *
026 * @see org.apache.tapestry5.services.javascript.ModuleManager#writeInitialization(org.apache.tapestry5.dom.Element, java.util.List, java.util.List)
027 * @since 5.4
028 */
029public interface DocumentLinker
030{
031
032    /**
033     * Adds a link to load a non-core JavaScript library. These libraries are loaded, sequentially, only once
034     * the core libraries have loaded and initialized. Thus difference between core libraries and other libraries
035     * is new in 5.4, and represents a conflict between asynchronous loading of modules (introduced in 5.4) and
036     * sequential loading of libraries (in 5.3 and earlier).
037     */
038    void addLibrary(String libraryURL);
039
040    /**
041     * A special case used only for the libraries that are part of the core stack, which itself contains RequireJS
042     * and is used to bootstrap up to adding non-core libraries.
043     *
044     * @since 5.4
045     */
046    void addCoreLibrary(String libraryURL);
047
048    /**
049     * Adds a link to load a CSS stylesheet.
050     */
051    void addStylesheetLink(StylesheetLink stylesheet);
052    
053    /**
054     * Adds a module configuration callback for this request.
055     * 
056     * @param callback a {@link ModuleConfigurationCallback}. It cannot be null.
057     * @since 5.4
058     */
059    void addModuleConfigurationCallback(ModuleConfigurationCallback callback);
060
061    /**
062     * Adds JavaScript code. The code is collected into a single block that is injected just before the close body tag
063     * of the page (in a full page render) and collected as the "script" property of the partial page render response.
064     * The JavaScript is executed after the page loads (or in an Ajax update, after external JavaScript libraries are
065     * loaded and the DOM is updated).
066     * <p/>
067     * This method may be called multiple times for the same priority and the script will be accumulated.
068     *
069     * @param priority
070     *         when to execute the provided script
071     * @param script
072     *         statement to add to the block (a newline will be appended as well)
073     */
074    void addScript(InitializationPriority priority, String script);
075
076    /**
077     * Adds initialization, based on invoking functions exported by JavaScript modules.
078     *
079     * @param priority
080     *         priority at which to perform initialization
081     * @param moduleName
082     *         name of module; the module exports a single function, or a map of functions
083     * @param functionName
084     *         name of function exported by module, or null (if the module exports a single function)
085     * @param arguments
086     *         arguments to pass to the function, or null if no arguments
087     * @since 5.4
088     */
089    void addInitialization(InitializationPriority priority,
090                           String moduleName,
091                           String functionName,
092                           JSONArray arguments);
093}