Parameter.java

package com.rapidminer.tools.parameter;

import com.rapidminer.parameter.ParameterType;

/**
 * Value and Definition of a Parameter. Two types of parameters can be defined:
 * Implicit ones and Defined ones. The defined one have a type definition, while the implicit
 * ones only have a key and value. Only defined parameters can be edited using the GUI and will be
 * saved in the config files.
 * 
 * @author Sebastian Land
 */
public class Parameter {
    ParameterType type = null;
    String group;
    String value;
    private ParameterScope scope = new ParameterScope();

    /**
     * This creates a new implicit Parameter.
     */
    public Parameter(String value) {

    }

    /**
     * This creates a new defined Parameter with a default scope and an undefined value.
     * 
     * The group of the Parameter is set automatically by the second segment of the dot separated
     * key. For setting the group explicitly, please use {@link #Parameter(ParameterType, String)}.
     * 
     * @param type
     */
    public Parameter(ParameterType type) {
        this.type = type;
        this.value = type.getDefaultValueAsString();
        if (value == null)
            value = "";

        String[] parts = type.getKey().split("\\.");
        if ("rapidminer".equals(parts[0])) {
            this.group = parts[1];
        } else {
            this.group = "system";
        }
    }

    public Parameter(ParameterType type, String group) {
        this.type = type;
        this.group = group;
        this.value = type.getDefaultValueAsString();
        if (value == null)
            value = "";

    }

    /**
     * Sets the value of this parameter. If the given value is null,
     * it is automatically converted to an empty String.
     */
    public void setValue(String value) {
        if (value == null)
            throw new NullPointerException();
        else
            this.value = value;
    }

    /**
     * This method returns whether this parameter is a defined type. With a
     * description, valid value range and name.
     * Only defined types can be edited in the GUI, all others can only be set
     * directly using system properties.
     */
    public boolean isDefined() {
        return type != null;
    }

    /**
     * This returns the scope of this parameter if it is a defined parameter.
     */
    public ParameterScope getScope() {
        return scope;
    }

    /**
     * Returns the actual value or an empty String if no values has been set.
     */
    public String getValue() {
        return value;
    }

    /**
     * This returns the group of this parameter.
     */
    public String getGroup() {
        return group;
    }

    /**
     * Returns the type of this parameter.
     */
    public ParameterType getType() {
        return type;
    }

    /**
     * This converts this parameter from an implicit Parameter into a defined one.
     */
    public void setType(ParameterType type) {
        this.type = type;
        String[] parts = type.getKey().split("\\.");
        if ("rapidminer".equals(parts[0])) {
            this.group = parts[1];
        } else {
            this.group = "system";
        }
    }

    /**
     * This sets the scope to the given one.
     */
    public void setScope(ParameterScope scope) {
        this.scope = scope;
    }

    /**
     * This method allows to set the group explicitly.
     */
    public void setGroup(String group) {
        this.group = group;
    }
}