Breadcrumb - gtosto/struts2-arianna-plugin GitHub Wiki

The Arianna Plugin use @BreadCrumb annotations to detect actions and/or methods that needs to be stored in a breadcrumb trail.

The @BreadCrumb annotation can be used both at class or method level, and it can have the following attributes:

To declare an action as one to track, by the plugin, you annotate the class as follows

@BreadCrumb("My Crumb Name")
public class MyAction {

  public String execute() {
    // action's code
    ...
  }

or you can annotate the method that struts will call (by default the execute method)

public class MyAction {

  @BreadCrumb("My Crumb Name")
  public String execute() {
    // action's code
    ...
  }

when struts² invokes MyAction a crumb with name "My Crumb Name" is created and appended to the application's breadcrumb bar.

If your actions are mapped to different methods of the same class they can also be individually marked with different annotations

public class ActionClass {

  public String notTrackedMethod() {
    ...
  }

  @BreadCrumb("Action A")
  public String methodA() {
    ...
  }
        
  @BreadCrumb("Action B")
  public String methodB() {
    ...
  }

when the actions mapped to methodA or methodB are called a crumb with name "Action A" or "Action B" (respectively) will be added to the breadcrumb.

Bread crumbs names can also be OGNL expressions, just use the %{ ... } syntax to denote expressions.

@BreadCrumb("%{crumbName}")
public class MyAction {

  public String getCrumbName() {
    return "Hello";
  }

  public String execute() {
    ...
  }

the plugin will then evaluate the OGNL expression against the action's value stack to get the actual crumb name (i.e a crumb named Hello will be added to the application's breadcrumb).

Sometimes you would give a name that is know only after the action execution, in this case setting the afterAction atribute to true defer the expression evaluation to the end of the action execution (but before the view rendering).

@BreadCrumb(value="%{deferredName}", afterAction=true)
public class MyAction {

  private String deferredName;

  public String getDeferredName() {
    return deferredName;
  }

  public String execute() {
    // action logic
    ...
    // set/update dynamic name
    deferredName = "a name depending from the action logic"
  }

If not specified otherwise, each tracked action will use the rewind mode (and comparator class) defined by the breadcrumb interceptor, however both rewind mode and comparator can be overrided by any single annotation. To force an action to have a particular behavior you can use the rewind and comparator attributes.

@BreadCrumb(value="Rewind to my last call", rewind=RewindMode.AUTO, comparator=ActionComparator.class)
public class MyAction {

  public String execute() {
     ...
  }