001// Copyright 2008, 2009, 2010, 2011 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.services.javascript;
016
017import org.apache.tapestry5.Asset;
018import org.apache.tapestry5.dom.Document;
019import org.apache.tapestry5.dom.Element;
020import org.apache.tapestry5.internal.TapestryInternalUtils;
021import org.apache.tapestry5.internal.services.DocumentLinker;
022import org.apache.tapestry5.ioc.internal.util.InternalUtils;
023
024/**
025 * Captures the information needed to create a stylesheet link in the final {@link Document}, or
026 * as part of a JSON partial page render response.
027 *
028 * @see DocumentLinker
029 * @see JavaScriptStack
030 * @since 5.2.0
031 */
032public final class StylesheetLink
033{
034    private final Asset asset;
035
036    private final String url;
037
038    private final StylesheetOptions options;
039
040    private static final StylesheetOptions BLANK_OPTIONS = new StylesheetOptions(null);
041
042    public StylesheetLink(Asset asset)
043    {
044        this(asset, null, null);
045    }
046
047    public StylesheetLink(Asset asset, StylesheetOptions options)
048    {
049        this(asset, null, options);
050    }
051
052    public StylesheetLink(String url)
053    {
054        this(null, url, null);
055    }
056
057    public StylesheetLink(String url, StylesheetOptions options)
058    {
059        this(null, url, options);
060    }
061
062    private StylesheetLink(Asset asset, String url, StylesheetOptions options)
063    {
064        assert asset != null || InternalUtils.isNonBlank(url);
065
066        this.asset = asset;
067        this.url = url;
068        this.options = options != null ? options : BLANK_OPTIONS;
069    }
070
071    public String getURL()
072    {
073        // Only one of asset or url will be non-null.
074        // Starting in 5.4, we keep the asset around and ask it for its clientURL; this is because
075        // clientURLs can change if the content of the underlying Resource changes.
076        return asset != null ? asset.toClientURL() : url;
077    }
078
079    /**
080     * Returns an instance of {@link StylesheetOptions}. Never returns null (a blank options
081     * object is returned if null is passed to the constructor).
082     */
083    public StylesheetOptions getOptions()
084    {
085        return options;
086    }
087
088    /**
089     * Invoked to add the stylesheet link to a container element.
090     *
091     * @param container
092     *         to add the new element to
093     */
094    public void add(Element container)
095    {
096        boolean hasCondition = InternalUtils.isNonBlank(options.condition);
097
098        if (hasCondition)
099        {
100            container.raw(String.format("\n<!--[if %s]>\n", options.condition));
101        }
102
103        String rel = options.ajaxInsertionPoint ? "stylesheet t-ajax-insertion-point" : "stylesheet";
104
105        container.element("link",
106                "href", getURL(),
107                "rel", rel,
108                "type", "text/css",
109                "media", options.media);
110
111        if (hasCondition)
112        {
113            container.raw("\n<![endif]-->\n");
114        }
115    }
116
117    @Override
118    public String toString()
119    {
120        return String.format("StylesheetLink[%s %s]", url, options);
121    }
122
123    @Override
124    public boolean equals(Object obj)
125    {
126        if (obj == this)
127            return true;
128
129        if (obj == null || !(obj instanceof StylesheetLink))
130            return false;
131
132        StylesheetLink ssl = (StylesheetLink) obj;
133
134        return TapestryInternalUtils.isEqual(getURL(), ssl.getURL()) && TapestryInternalUtils.isEqual(options, ssl.options);
135    }
136
137}