fmpp.models.JSONObjectNode Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of fmpp Show documentation
General-purpose text file preprocessor tool that uses FreeMarker templates.
There is a newer version: 0.9.16
package fmpp.models;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
import freemarker.template.TemplateNodeModel;
import freemarker.template.TemplateSequenceModel;

/**
 * JSON "object" value; see http://www.json.org/.
 * This class is NOT thread safe.
 */
public class JSONObjectNode extends JSONNode implements TemplateHashModelEx {

    private static final long serialVersionUID = 1L;
    
    public static final String NODE_TYPE = "object"; 
    public static final String DEFAULT_NODE_NAME = nodeTypeToDefaultNodeName(NODE_TYPE);
    
    private final Map/**/ map;

    /**
     * @param map The JSON name-value pairs. The keys must be {@link String}-s, and values must be of a type that
     *          {@link JSONNode#wrap(Object)} can wrap. 
     */
    public JSONObjectNode(JSONNode parentNode, String nodeName, Map/**/ map) {
        super(parentNode, nodeName);
        this.map = map;
    }

    public String getNodeType() throws TemplateModelException {
        return NODE_TYPE;
    }

    /**
     * Returns the {@link JSONNode} for the given key from this JSON object, using a Java {@code null} for JSON
     * {@code null}-s. Note that {@link #getChildNodes()} treats JSON {@code null}-s differently.
     */
    public TemplateModel get(String key) throws TemplateModelException {
        return wrap(map.get(key), this, key, false);
    }

    public boolean isEmpty() throws TemplateModelException {
        return map.isEmpty();
    }

    public int size() throws TemplateModelException {
        return map.size();
    }
    
    public TemplateSequenceModel getChildNodes() throws TemplateModelException {
        return new JSONChildNodeSequence(map.entrySet());
    }
    
    public TemplateCollectionModel keys() throws TemplateModelException {
        return new JSONKeyCollection(map.keySet());
    }

    /**
     * Returns the values from the key-value pairs of this JSON object, returning Java {@code null} for JSON
     * {@code null}-s. Note that {@link #getChildNodes()} treats JSON {@code null}-s differently.
     */
    public TemplateCollectionModel values() throws TemplateModelException {
        return new JSONValueCollection(map.entrySet());
    }

    private class JSONChildNodeSequence implements TemplateSequenceModel, TemplateCollectionModel {

        private final Collection/*>*/ entries;
        
        private TemplateNodeModel[] wrappedValues;
        
        private JSONChildNodeSequence(Collection/*>*/ entries) {
            this.entries = entries; 
        }

        public TemplateModelIterator iterator() throws TemplateModelException {
            if (this.wrappedValues == null) {
                initializeWrappedValues();
            }
            return new TemplateModelIterator() {
                
                private int nextIdx;

                public boolean hasNext() throws TemplateModelException {
                    return nextIdx < wrappedValues.length;
                }

                public TemplateModel next() throws TemplateModelException {
                    return wrappedValues[nextIdx++];
                }
                
            };
        }

        public TemplateModel get(int idx) throws TemplateModelException {
            TemplateNodeModel[] wrappedValues = this.wrappedValues;
            if (wrappedValues == null) {
                wrappedValues = initializeWrappedValues();
            }
            
            if (idx < 0 || idx >= wrappedValues.length) {
                throw new TemplateModelException("JSON object child node index out of bounds: " + idx
                        + " is outside 0.." + (wrappedValues.length - 1));
            }
            return wrappedValues[idx];
        }

        protected TemplateNodeModel[] initializeWrappedValues() throws TemplateModelException {
            TemplateNodeModel[] wrappedValues;
            wrappedValues = new TemplateNodeModel[size()];
            int dstIdx = 0;
            for (Iterator it = entries.iterator(); it.hasNext();) {
                final Map.Entry/**/ entry = (Entry) it.next();
                wrappedValues[dstIdx++] = wrap(entry.getValue(), JSONObjectNode.this, (String) entry.getKey(), true);
            }
            return this.wrappedValues = wrappedValues;
        }

        public int size() throws TemplateModelException {
            return entries.size();
        }
        
    }
    
    private class JSONKeyCollection implements TemplateCollectionModel {

        private final Collection/**/ values;
        
        private JSONKeyCollection(Collection/**/ values) {
            this.values = values; 
        }

        public TemplateModelIterator iterator() throws TemplateModelException {
            return new TemplateModelIterator() {
                
                Iterator it = values.iterator();

                public boolean hasNext() throws TemplateModelException {
                    return it.hasNext();
                }

                public TemplateModel next() throws TemplateModelException {
                    return wrap(it.next(), JSONObjectNode.this, null, false);
                }
                
            };
        }
        
    }

    private class JSONValueCollection implements TemplateCollectionModel {

        private final Collection/*>*/ values;
        
        private JSONValueCollection(Collection/*>*/ values) {
            this.values = values; 
        }

        public TemplateModelIterator iterator() throws TemplateModelException {
            return new TemplateModelIterator() {
                
                Iterator it = values.iterator();

                public boolean hasNext() throws TemplateModelException {
                    return it.hasNext();
                }

                public TemplateModel next() throws TemplateModelException {
                    final Map.Entry/**/ entry = (Entry) it.next();
                    return wrap(entry.getValue(), JSONObjectNode.this, (String) entry.getKey(), false);
                }
                
            };
        }
        
    }
    
    protected String getDefaultNodeName() {
        return DEFAULT_NODE_NAME;
    }
    
}