001package ca.uhn.hl7v2.model;
002
003import java.io.Serializable;
004import java.util.ArrayList;
005import java.util.List;
006
007/**
008 * A set of "extra" components (sub-components) that are not a standard part 
009 * of a field (component) but have been added at runtime.  The purpose is to allow 
010 * processing of locally-defined extensions to datatypes without the need for a 
011 * custom message definition.  
012 * Extra components are not treated uniformly with standard components (e.g. 
013 * they are not accessible through methods like Primitive.getValue() and 
014 * Composite.getComponent()).  To do so would blur the distinction between 
015 * primitive and composite types (i.e. leaf and non-leaf nodes), which seems 
016 * nice and polymorphic for a moment but actually isn't helpful.  
017 * Furthermore, the auto-generated classes do not define accessors to extra 
018 * components, because they are meant to encourage and enforce use of the standard 
019 * message structure -- stepping outside the standard structure must be 
020 * deliberate. 
021 * Note that a uniformity of access to standard and extra components is provided
022 * by Terser.   
023 * @author Bryan Tripp
024 */
025public class ExtraComponents implements Serializable {
026    
027
028        private static final long serialVersionUID = -2614683870975956395L;
029    
030    private List<Varies> comps;
031    private Message message;
032    
033    /** Creates a new instance of ExtraComponents */
034    public ExtraComponents(Message message) {
035        this.comps = new ArrayList<Varies>();
036        this.message = message; 
037    }
038    
039    /** Returns the number of existing extra components */
040    public int numComponents() {
041        return comps.size();
042    }
043    
044    /** Returns the number of existing reps of a given extra component */
045    /*public int numReps(int comp) {
046        return ((ArrayList) this.comps.get(comp)).size();
047    }*/
048    
049    /** 
050     * Returns the component at the given location, creating it 
051     * and all preceeding components if necessary.  
052     * @param comp the extra component number starting at 0 (i.e. 0 is the first 
053     *      extra component)
054     */
055    public Varies getComponent(int comp) {
056        ensureComponentAndPredecessorsExist(comp);
057        return this.comps.get(comp);
058    }
059    
060    /**
061     * Checks that the component at the given location exists, and that 
062     * all preceding components exist, creating any missing ones.  
063     */
064    private void ensureComponentAndPredecessorsExist(int comp) {
065        for (int i = this.comps.size(); i <= comp; i++) {
066            this.comps.add(new Varies(message));
067        }
068        /*ArrayList reps = (ArrayList) this.comps.get(comp);
069        for (int j = reps.size(); j <= rep; j++) {
070            addRep(comp, j);
071        }*/
072    }
073
074
075        /**
076         * Clears all extra components
077         */
078        void clear() {
079                comps.clear();
080        }
081
082    /**
083     * {@inheritDoc}
084         */
085        @Override
086        public String toString() {
087                return "ExtraComponents" + comps;
088        }
089        
090
091    /*private void addComp(int comp) {
092    }*/
093    
094    /*private void addRep(int comp, int rep) {
095        ArrayList l = (ArrayList) this.comps.get(comp);
096        l.add(rep, new Varies());
097    }*/
098}