parameters - gtosto/struts2-arianna-plugin GitHub Wiki

Interceptor's parameters

Parameter	Type	Description	Default
`trail.maxCrumbs`	number	The maximum number of crumbs to keep stored.	`6`
`trail.rewindMode`	String	The default rewind mode. Valid values are `NEVER` and `AUTO`	`AUTO`
`trail.comparator`	String	The fully qualified class name of the default comparator to use when checking for crumb equality.	`xyz.timedrain.arianna.plugin.NameComparator`

Rewind mode

The rewindMode parameter deals with duplicated crumbs. What duplicated means depends by the comparator actually used (see below).

When the rewind mode is NEVER the plugin will never rewind the bread crumbs and it will allow the bread crumbs trail to have duplicated crumbs.

When the rewind mode is AUTO duplicated crumbs are not allowed. If you invoke an action that would create a crumb that yields an already existing crumb, the plugin will rewind the crumbs trail to that crumb replacing the old crumb with the newest one.

For example if the current bread crumb is

Action1 > Action2 > Action3 > Action4

and the next invoked action creates a crumb that is equals to the Action2 the trail will be rewound to

Action1 > Action2

<a href='Hidden comment: NOTE When the rewind mode is NEVER you could expext that a new Crumb is ALWAYS added to the trail. This is not true. If last crumb is equals to the current one it will replace the oldest with the newest. Without regards the rewind mode.

Even if rewind mode is NEVER but the current Crumb is equals to the last one the plugin '>

Crumb Comparator

The plugin will (create and) use an instance of the class specified by this parameter to compare crumbs for equality.

The arianna-plugin provides 3 ready-to-use comparators

xyz.timedrain.arianna.plugin.NameComparator That compares crumbs only checking its names.
xyz.timedrain.arianna.plugin.ActionComparator This comparator will compare the namespace, action and method properties of two crumbs.
xyz.timedrain.arianna.plugin.RequestComparator This comparator will compare the action identity like the ActionComparator does, but besides will also check request parameter (name and values) for equalities.

User Defined Comparators

if none of the built-in comparator meets your needs, you can also write your own custom comparator. Just implement the java.util.Comparator<Crumb> interface and write the desired logic. For example

public class MyComparator implements Comparator<Crumb>
{
    public int compare(Crumb c1, Crumb c2) {
      // my custom comparing logic
    }
}