SLG Router - hpi-swa-teaching/SqueakLanguageLearning GitHub Wiki

SLGRouter is the class which handles navigation within our app. The instance of this class manages all the pages in the app by putting them into an dictionary with a string as key and page as value. Everything this Router does is showing and hiding pages.

Route String	Page Instance
/home	SLGHomePageView instance
/home/Data Types	SLGTopicPageView instance with "Data Types" data
...	...

• We show only one page at the time
• The Route string can be an arbitrary string of any format

Route to a specific page:

navigateTo: '/home'

Navigate back

There is also a method called navigateBack which returns to the previous page. This is implemented as a stack. Each time we navigate, we add a page to the stack. This means the page which is visible is always on top of the stack. This means navigating back means popping the stack.

Updating a page on navigateTo

When we navigate to a page we potentially want it to update some of it's UI components. The router tries to call a method named refresh in case the page has this method implemented. A refresh method is optionally.

All pages have access to the navigateTo: ... and navigateBack method. The router is passed as part of SLGMainController to all the pages.

Example Code

| router |
router := SLGRouter new.

" Register routes "
router addRouteWithPath: '/home' withPage: Morph new.
router addRouteWithPath: '/home/subpage1' withPage: Morph new.

" Shows homepage "
router navigateTo: '/home'. 

" Hides homepage and  shows subpage "
router navigateTo: '/home/subpage1'.

" Hides subpage and shows homepage "
router navigateBack.