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/ParameterizedCommand.java
* parameter is <code>null</code>.
	 * </p>
	 * <p>
	 * For example, the string shown below represents a serialized parameterized
	 * command that can be used to show the Resource perspective:
	 * </p>
	 * <p>
	 * <code>org.eclipse.ui.perspectives.showPerspective(org.eclipse.ui.perspectives.showPerspective.perspectiveId=org.eclipse.ui.resourcePerspective)</code>
	 * </p>
	 * <p>
	 * This example shows the more general form with multiple parameters,
	 * <code>null</code> value parameters, and escaped <code>=</code> in the
	 * third parameter value.
	 * </p>
	 * <p>
	 * <code>command.id(param1.id=value1,param2.id,param3.id=esc%=val3)</code>
	 * </p>
	 * 
	 * @return A string containing the escaped command id, parameter ids and
	 *         parameter values; never <code>null</code>.
	 * @see CommandManager#deserialize(String)
	 * @since 3.2
	 */
	public final String serialize() {
		final String escapedId = escape(getId());
		if ((parameterizations == null) || (parameterizations.length == 0)) {
			return escapedId;
		}
		final StringBuffer buffer = new StringBuffer(escapedId);
		buffer.append(CommandManager.PARAMETER_START_CHAR);