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/ExecutionEvent.java
}
		this.parameters = parameters;
		this.trigger = trigger;
		this.applicationContext = applicationContext;
	}
	/**
	 * Returns the state of the application at the time the execution was
	 * triggered.
	 * 
	 * @return The application context; may be <code>null</code>.
	 */
	public final Object getApplicationContext() {
		return applicationContext;
	}
	/**
	 * Returns the value of the parameter with the given id.
	 * 
	 * @param parameterId
	 *            The id of the parameter to retrieve; may be <code>null</code>.
	 * @return The parameter value; <code>null</code> if the parameter cannot
	 *         be found.
	 */
	public final String getParameter(final String parameterId) {
		return (String) parameters.get(parameterId);
	}
	/**
	 * Returns all of the parameters.
	 * 
	 * @return The parameters; never <code>null</code>, but may be empty.
	 */