Bug 121709 [Commands] parameters: Add types
I'm going to attach a patch that adds support for typed command parameters. This addresses several issues: - parameter values are strings, but handlers may want to work on objects - multiple handlers of a command should have a consistent way of converting string parameter values to objects - tooling to construct parameterized commands that starts with object parameter values needs a way of producing string parameter values that will work when the command is executed - there should be a way to classify commands by their object parameter types so, given an object, a set of commands that may work with it can be suggested To address these issues, the patch allows parameter types to be declared in the extension-point XML. The example below defines a command for negating integers and a parameter type that works with it. <extension point="org.eclipse.ui.commands"> <command id="org.example.commands.negateInteger" defaultHandler="org.example.commands.NegateIntegerHandler" name="Negate an Integer"> <commandParameter id="param" name="the param" optional="false" typeId="org.example.commands.Integer"/> </command> <commandParameterType id="org.example.commands.Integer" converter="org.example.commands.IntegerConverter" type="java.lang.Integer"/> </extension> In addition to extending the schema for org.eclipse.ui.commands, code has been added to a number of plugins (primarily org.eclipse.core.commands) to support the notion of typed parameters.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/CommandManager.java
public final Set getDefinedCommandIds() {
		return getDefinedHandleObjectIds();
	}
	/**
	 * Returns the those commands that are defined.
	 * 
	 * @return The defined commands; this value may be empty, but it is never
	 *         <code>null</code>.
	 * @since 3.2
	 */
	public final Command[] getDefinedCommands() {
		return (Command[]) definedHandleObjects
				.toArray(new Command[definedHandleObjects.size()]);
	}
	/**
	 * Returns an array of parameterizations for the provided command by
	 * deriving the parameter ids and values from the provided
	 * <code>serializedParameters</code> string.
	 * 
	 * @param serializedParameters
	 *            a String encoding parameter ids and values; must not be
	 *            <code>null</code>.
	 * @param parameters
	 *            array of parameters of the command being deserialized; may be
	 *            <code>null</code>.
	 * @return an array of parameterizations; may be <code>null</code>.
	 * @throws NotDefinedException
	 *             if the command is not defined
	 * @throws SerializationException
	 *             if there is an error deserializing the parameters