com.google.gdata.wireformats.GeneratorUtils.java Source code

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Here is the source code for com.google.gdata.wireformats.GeneratorUtils.java

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/**
 * Mule Google Api Commons
 *
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 *
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */

package com.google.gdata.wireformats;

import com.google.common.collect.Maps;
import com.google.gdata.util.common.xml.XmlNamespace;
import com.google.gdata.model.Attribute;
import com.google.gdata.model.AttributeKey;
import com.google.gdata.model.AttributeMetadata;
import com.google.gdata.model.Element;
import com.google.gdata.model.ElementMetadata;
import com.google.gdata.model.QName;

import java.util.Iterator;
import java.util.Map;

/**
 * Utility functions shared across generators.
 *
 * 
 */
public class GeneratorUtils {

    /**
     * Calculate the set of namespaces on an element.  This will find all
     * namespaces declared on the element or child elements, ordered in
     * depth-first order.
     */
    public static Map<String, XmlNamespace> calculateNamespaces(Element root, ElementMetadata<?, ?> metadata) {
        Map<String, XmlNamespace> namespaceMap = Maps.newHashMap();
        calculateNamespaces(namespaceMap, root, metadata);
        return namespaceMap;
    }

    /**
     * Calculate the namespaces on an element using the given visitor to store
     * the namespaces.  We cheat by using an attribute visitor for even visiting
     * the element names, because all we're doing with the visitor is adding a
     * QName.
     */
    private static void calculateNamespaces(Map<String, XmlNamespace> namespaces, Element e,
            ElementMetadata<?, ?> metadata) {
        QName name = (metadata == null) ? e.getElementId() : metadata.getName();
        addNamespace(namespaces, name);

        Iterator<Attribute> attIter = e.getAttributeIterator(metadata);
        while (attIter.hasNext()) {
            Attribute att = attIter.next();
            AttributeKey<?> attKey = att.getAttributeKey();
            AttributeMetadata<?> attMeta = (metadata == null) ? null : metadata.bindAttribute(attKey);
            name = (attMeta == null) ? attKey.getId() : attMeta.getName();
            addNamespace(namespaces, name);
        }

        Iterator<Element> childIter = e.getElementIterator(metadata);
        while (childIter.hasNext()) {
            Element child = childIter.next();
            ElementMetadata<?, ?> childMeta = (metadata == null) ? null
                    : metadata.bindElement(child.getElementKey());
            calculateNamespaces(namespaces, child, childMeta);
        }
    }

    /**
     * Add a qualified name to the map by URI.  Only the first namespace with a
     * given URI is added to the map.
     */
    private static void addNamespace(Map<String, XmlNamespace> namespaces, QName name) {
        if (name == null) {
            return;
        }
        XmlNamespace ns = name.getNs();
        if (ns == null) {
            return;
        }
        String alias = ns.getAlias();
        if (alias == null) {
            return;
        }
        String uri = ns.getUri();
        if (namespaces.containsKey(uri)) {
            return;
        }
        namespaces.put(uri, ns);
    }
}