<args:get/>Description
<args:get>. An extremely powerful tag that takes a named
table and can create properties by key/value in all of its child
nodes [not recursively - this is deliberate], or it can create
substitution nodes where any child node with the same key name
will be replaced with the value [which does work recursively].
<args:get> also has a mode where each key/value pair
in a named table can be used to create a new two-entry
table with each key and value as its only two entries, which
are then actioned on each of the child nodes.
Examples
Closest conceptual equivalent
it's basically looking up records in a database, and then
turning each individual record into its own mini-database,
where the record is just the key/value pair.
TODO
[instead of using apache tables as the means to store the
args data, use an in-memory XML document.]
<args:set/>Description
The reverse of <args:set/>.
<auth:login/><auth:login/> checks the user's password, hands them a
cookie, which gives the site just enough state information to
not have to ask them their password on every single page page.
Has been abstracted / divorced from the rest of the code to make it possible to replace login/ with, say, Unix or Apache-specific User Authorisation methods.
<cert:check/>Description
<cert:check>. Checks that a user has a Certification
of a specific type above a specific level. The cached results
are read and used: the <cert:check> does not do the
[potentially expensive] calculations on-demand. To generate
a certification calculation, use <tm:calc/>.
Examples
Closest conceptual equivalent
Evaluation of an Access Control Entry (ACE, from which ACLs -
Access Control Lists - are constructed).
<expr:eval/>Description
<expr:eval>. I was getting fed up of the number of
hard-coded expression evaluations, so added a tag that returns
either "true" or empty string [nothing]. has type="or", "and",
"not" and "equal" properties which act as hopefully expected!.
Examples
Closest conceptual equivalent
sh shell-script expression evaluations. Assumed to be used
in conjunction with the <expr:if/> tag, although if you
use <expr:eval/> on its own, it is assumed that you
do not mind the word "true" occasionally appearing in your
output stream.
TODO
planned: type="lessthan" and type="greater", which will convert
their string contents to numbers and compare them.
<expr:if/>Description
<expr:if/>. Surprise, surprise. works in combination
with immediate-child-nodes. all children up to a <then/>
or <else/> are evaluated until one of them returns a
string with actual characters in it [i.e. not white space].
After that, all other child nodes are skipped until [or if] a
<then/> or <else/> child node is found. if there
was at least one non-white-space node up to that point, the
child nodes of <then/> are evaluated [if it exists].
otherwise, the child nodes of <else/> are evaluated
[if it exists].
Even with no <else/> or <then/> nodes,
<expr:if/> has enough logic to be useful. to somebody.
Examples
TODO
[consider replacing <else/> with <expr:else/> and
likewise for then. MCSE XML (must consult some experts in XML)].
<tm:calc/>Description
<tm:calc>. The entire reason this project was
started: Trust Metric Calculation. This will go walkabout
all over the site database, reading in Certifications from
profiles, performing a number of Maximum Flow Graph Evaluations
and then outputting the results to an XML results-cache file.
To be used in conjunction with various [to a lesser or greater
extent, hard-coded] tags such as <cert:check/>.
Examples
Closest conceptual equivalent
Closest conceptual equivalent: Hierarchical Access Control Lists
(ACLs). Aka HACLs or HACs. (only kidding).
TODO
A future modification to this tag will include loading of remote
profiles from other sites. Additionally, Digital Signatures
will be validated on user's Certifications.