org.apache.shindig.gadgets.spec.ApplicationManifest.java Source code

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Here is the source code for org.apache.shindig.gadgets.spec.ApplicationManifest.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.shindig.gadgets.spec;

import org.apache.shindig.common.uri.Uri;

import com.google.common.collect.ImmutableMap;

import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * Represents an opensocial application manifest.
 */
public class ApplicationManifest {
    public static final String NAMESPACE = "http://ns.opensocial.org/2008/application";

    private final Map<String, String> versions;
    private final Map<String, Uri> gadgets;
    private final Uri uri;

    public ApplicationManifest(Uri uri, Element xml) throws SpecParserException {
        ImmutableMap.Builder<String, String> versions = ImmutableMap.builder();
        ImmutableMap.Builder<String, Uri> gadgets = ImmutableMap.builder();

        NodeList nodes = xml.getElementsByTagName("gadget");
        for (int i = 0, j = nodes.getLength(); i < j; ++i) {
            Element gadget = (Element) nodes.item(i);
            String version = getVersionString(gadget);
            Uri spec = getSpecUri(uri, gadget);
            gadgets.put(version, spec);
            for (String label : getLabels(gadget)) {
                versions.put(label, version);
            }
        }

        this.uri = uri;
        this.versions = versions.build();
        this.gadgets = gadgets.build();
    }

    private static Uri getSpecUri(Uri baseUri, Element gadget) throws SpecParserException {
        NodeList specs = gadget.getElementsByTagName("spec");

        if (specs.getLength() > 1) {
            throw new SpecParserException("Only one spec per gadget block may be specified.");
        } else if (specs.getLength() == 0) {
            throw new SpecParserException("No spec specified.");
        }

        try {
            String relative = specs.item(0).getTextContent();
            Uri specUri = baseUri.resolve(Uri.parse(relative));
            if (specUri.equals(baseUri)) {
                throw new SpecParserException("Manifest is self-referencing.");
            }
            return specUri;
        } catch (IllegalArgumentException e) {
            throw new SpecParserException("Invalid spec URI.");
        }
    }

    private static String getVersionString(Element gadget) throws SpecParserException {
        NodeList versions = gadget.getElementsByTagName("version");

        if (versions.getLength() > 1) {
            throw new SpecParserException("Only one version per gadget block may be specified.");
        } else if (versions.getLength() == 0) {
            throw new SpecParserException("No version specified.");
        }

        return versions.item(0).getTextContent();
    }

    private static List<String> getLabels(Element gadget) {
        NodeList labels = gadget.getElementsByTagName("label");
        List<String> list = new ArrayList<String>(labels.getLength());

        for (int i = 0, j = labels.getLength(); i < j; ++i) {
            list.add(labels.item(i).getTextContent());
        }

        return list;
    }

    /**
     * @return The URI of this manifest.
     */
    public Uri getUri() {
        return uri;
    }

    /**
     * @return The gadget specified for the version string, or null if the version doesn't exist.
     */
    public Uri getGadget(String version) {
        return gadgets.get(version);
    }

    /**
     * @return The version of the gadget for the given label, or null if the label is unsupported.
     */
    public String getVersion(String label) {
        return versions.get(label);
    }
}