[CAUSEWAY-1740] New Feature: Where am I

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.0.0-M1
• Component/s: Core
• Assignee: Andi Huber
• Reporter: Andi Huber
• Created: 27/Sep/17 07:19
• Updated: 16/Feb/18 13:33
• Resolved: 16/Feb/18 13:33

Description

Its common practice to display a navigation hint somewhere at top of an application's page or below the main menu, indicating where the user currently has navigated to. (Typically within a navigable tree-structure.)

Let's call this the WhereAmI hint. We could integrate such a feature into ISIS.

Examples
Clipboard01.png
Clipboard02.png
Clipboard03.png

Note: we could optionally include the DomainObject's icons

Proposal

For any DomainObject/View currently displayed ISIS would need to know its corresponding
navigable tree-structure. Let's call this the DomainObject's WhereAmI tree.

All the framework needs to known to build the relevant sub-tree, is to know the parent node of any DomainObject/View that 'takes part' in the tree.

We could provide this 'who is your parent' meta information similar to the existing 'what is your title' mechanism:

// Who is your parent? if null there is none
public AnyDomainObjectOrView parent()
{
    return foo;
}

or

// Who is your parent? if null there is none
@Parent
public AnyDomainObjectOrView anyMethodName()
{
    return foo;
}

The typical layout.xml could look like this:

<bs3:grid >
    <bs3:row>
        <bs3:col span="12" unreferencedActions="true">
            <cpt:whereAmI />
            <cpt:domainObject />
            ...
        </bs3:col>
    </bs3:row>
     ...
</bs3:grid >

Implementation Notes

1. The framework needs to ensure that the chain of parent references starting at the current DomainObject/View is finite. (No circular or self references.) If it detects a circle, be nice and just stop the 'tree-up' traversal there.
2. For standalone Collection Views we could display a WhereAmI hint that allows back navigation to the DomainObject/View that had produced the collection.

Issue Links

• depends upon: CAUSEWAY-1762 Java 8+ Miscellaneous Utilities
• relates to: CAUSEWAY-842 Rework the bookmark/breadcrumbs views.

Sub-Tasks

• Specify framework's behavior if multiple @Parent annotations or parent() methods are resolved in the object's hierarchy: Closed
• Documentation (guide) of where-am-i feature: Closed