The moving value: context_fragment
Each page in my scheme (remember, this whole thing is certainly not the only way), receives a value for context_fragment. This value will remain constant for the entire code of the page. It represents the value of context_fragment applicable to the PREVIOUS page.
To get this value, your page must state in the ad_page_contract, that it wants to receive it. I do that like this:
ad_page_contract {
this is where the docs and purpose for the page are stated
} -query {
contect_fragment
} -properties {
:
:
}
The page will now complain if the variable context_fragment is not passed.
The first thing we will do with it, is copy it into two variables, one called context and the other called new_cntxt_frag, like this:
set context $context_fragment
set new_cntxt_frag $context_fragment
and set the page title:
set title "Title for this Page"
adjust the value of context to have the title as its last list element, making it ready to present to the master template:
lappend context $title
add a new var containing a url to the current page (remember, this url must pass a value for context_fragment):
set self_url \
[export_vars \
-base this-page \
{context_fragment}]
and adjust new_cntxt_frag with a new two-element {url title} list, the value of which will be passed to "newer" pages, represents the context_fragment value for THIS page (not the previous page), and the navigation bar will be seen to have a new link when the page is rendered:
lappend new_cntxt_frag [list $self_url $title]
and, except for the first page, that's it. Each page does basically the same thing, and the navigation bar is just handled.
Next section: the first page
