Groovy example source code file (Attributes.java)

This example Groovy source code file (Attributes.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

attributes, gpathresult, gpathresult, io, iterator, iterator, list, map, nodechild, object, object, string, string, stringbuffer, util, writer

The Groovy Attributes.java source code

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * 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 groovy.util.slurpersupport;

import groovy.lang.Closure;
import groovy.lang.GroovyObject;
import groovy.lang.GroovyRuntimeException;

import java.io.IOException;
import java.io.Writer;
import java.util.Map;
import java.util.Iterator;
import java.util.List;
import java.util.ArrayList;

/**
 * Lazy evaluated representation of a node's attributes.
 *
 * @author John Wilson
 */
class Attributes extends NodeChildren {
    final String attributeName;

    /**
     * @param parent the GPathResult prior to the application of the expression creating this GPathResult
     * @param name if the GPathResult corresponds to something with a name, e.g. a node
     * @param namespacePrefix the namespace prefix if any
     * @param namespaceTagHints the known tag to namespace mappings
     */
    public Attributes(final GPathResult parent, final String name, final String namespacePrefix, final Map<String, String> namespaceTagHints) {
        super(parent, name, namespacePrefix, namespaceTagHints);
        this.attributeName = this.name.substring(1);
    }

    /**
     * @param parent the GPathResult prior to the application of the expression creating this GPathResult
     * @param name if the GPathResult corresponds to something with a name, e.g. a node
     * @param namespaceTagHints the known tag to namespace mappings
     */
    public Attributes(final GPathResult parent, final String name, final Map<String, String> namespaceTagHints) {
        this(parent, name, "*", namespaceTagHints);
    }

    public String name() {
        // this name contains @name we need to return name
        return this.name.substring(1);
    }

    public Iterator childNodes() {
        throw new GroovyRuntimeException("Can't get the child nodes on a GPath expression selecting attributes: ...." + this.parent.name() + "." + name() + ".childNodes()");
    }

    public Iterator iterator() {
        return new NodeIterator(nodeIterator()) {
            protected Object getNextNode(final Iterator iter) {
                while (iter.hasNext()) {
                    final Object next = iter.next();
                    if (next instanceof Attribute) {
                        return next;
                    } else {
                        final String value = (String) ((Node) next).attributes().get(Attributes.this.attributeName);
                        if (value != null) {
                            return new Attribute(Attributes.this.name,
                                    value,
                                    new NodeChild((Node) next, Attributes.this.parent.parent, "", Attributes.this.namespaceTagHints),
                                    "",
                                    Attributes.this.namespaceTagHints);
                        }
                    }
                }
                return null;
            }
        };
    }

    public Iterator nodeIterator() {
        return this.parent.nodeIterator();
    }

    public GPathResult parents() {
        return super.parents();
    }

    public String text() {
        final StringBuffer buf = new StringBuffer();
        final Iterator iter = iterator();
        while (iter.hasNext()) {
            buf.append(iter.next());
        }
        return buf.toString();
    }

    public List list() {
        final Iterator iter = iterator();
        final List result = new ArrayList();
        while (iter.hasNext()) {
            result.add(iter.next());
        }
        return result;
    }

    public GPathResult findAll(final Closure closure) {
        return new FilteredAttributes(this, closure, this.namespaceTagHints);
    }

    public Writer writeTo(final Writer out) throws IOException {
        out.write(text());
        return out;
    }

    public void build(final GroovyObject builder) {
        builder.getProperty("mkp");
        builder.invokeMethod("yield", new Object[]{text()});
    }
}