Groovy example source code file (NoChildren.java)

This example Groovy source code file (NoChildren.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

closure, closure, gpathresult, gpathresult, groovyobject, groovyruntimeexception, io, ioexception, iterator, iterator, nochildren, object, object, string, util, writer

The Groovy NoChildren.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.Iterator;
import java.util.Map;

/**
 * Lazy evaluated representation of a GPath expression returning no children.
 *
 * @author John Wilson
 */
public class NoChildren extends GPathResult {
    /**
     * @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 NoChildren(final GPathResult parent, final String name, final Map<String, String> namespaceTagHints) {
        super(parent, name, "*", namespaceTagHints);
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#size()
    */
    public int size() {
        return 0;
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#text()
    */
    public String text() {
        return "";
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#parents()
    */
    public GPathResult parents() {
        // TODO Auto-generated method stub
        throw new GroovyRuntimeException("parents() not implemented yet");
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#childNodes()
    */
    public Iterator childNodes() {
        return iterator();
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#iterator()
    */
    public Iterator iterator() {
        return new Iterator() {
            public boolean hasNext() {
                return false;
            }

            public Object next() {
                return null;
            }

            public void remove() {
                throw new UnsupportedOperationException();
            }
        };
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#find(groovy.lang.Closure)
    */
    public GPathResult find(final Closure closure) {
        return this;
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#findAll(groovy.lang.Closure)
    */
    public GPathResult findAll(final Closure closure) {
        return this;
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.util.slurpersupport.GPathResult#nodeIterator()
    */
    public Iterator nodeIterator() {
        return iterator();
    }

    /* (non-Javadoc)
    * @see groovy.lang.Writable#writeTo(java.io.Writer)
    */
    public Writer writeTo(final Writer out) throws IOException {
        return out;
    }

    /* (non-Javadoc)
    * @see org.codehaus.groovy.sandbox.markup.Buildable#build(groovy.lang.GroovyObject)
    */
    public void build(final GroovyObject builder) {
    }

    protected void replaceNode(final Closure newValue) {
        // No elements match GPath expression - do nothing
    }

    protected void replaceBody(final Object newValue) {
        // No elements match GPath expression - do nothing
    }

    protected void appendNode(final Object newValue) {
        // TODO consider creating an element for this
    }

    public boolean asBoolean() {
        return false;
    }
}