Re: [binarycloud-dev] Modules by tag

[alex b. <en...@tu...>]

Right, the "unique name" thing.

The problem with doing it this way (even though it works :) - is that it
relies on the user to setup module names in the page defs, instead of
providing a global, standard way of having modules communicate (and check
for communication). That adds an (as far as I am concerned) unnecessarily
complex "page setup" step which requires an developer integrating your
modules to look up Module names, put them in his/her page defs, etc. I can
see that getting unweildy very quickly.

I far prefer a MessageManager class which is capable of managing that
communication than an extension to page which allows us to name tag modules.

Any other opinions on this issue?

> I did a quick hack to Page to give me the ability to know
> what module to talk to by giving a module a "tag", and
> gaining access by using this "tag".
>
> I am only presenting it if someone wants to keep on
> writing modules and wishes to communicate between modules.
> This hack is, BY NO MEANS, some sort of suggestion for
> imcorporation.
>
> The steps are:
>
> 1.  Put in index.php a global array called Modules_by_tag, thus:
>
> $Modules_by_tag = array();
> // ripped from /path/to/binarycloud/user/htdocs/index.xml
> $bc_page = array(
> ...
>
> 2.  Add code in Page.php _IncludeModules($_group) thus:
> ...code...
>                 foreach ($modules[$_group]['load'] as $pos=>$mod) {
>                         import("user.mod.$mod[package].$mod[name]");
>                         $this->modules[$_group][$pos] = new
> $mod['name']($mod['options']);
> #== added by jef ==
> $tag    = $modules[$_group]['load'][$pos]['tag'];
> if (!empty($tag)) {
>         global $Modules_by_tag;
>         $Modules_by_tag[$tag] =& $this->modules[$_group][$pos];
> }
> #=================
>
> 4.  Add 'tag' as sppropriate in index.php for a module stanza, thus:
>     array(
>             'name'          => "Blank",
>             'package'       => "lib",
>             'load_order'    => "300",
>             'options'       => "appears 3rd",
>             'tag'           => "DataDictionary",
>     ),
>
> 5.  Access the tagged module properties/methods ANYWHERE thus:
> global $Modules_by_tag;
> $Modules_by_tag['DataDictionary']->whoami();
>
> It works...

If you were going to do this, I would suggest using an internal Page
variable, like

$Page->mod_tags['DataDictionary']->whoami();

It would not require any modification to the page def (except your addition,
which is clean) - and would not pollute the global var space.

I'm not averse to incorporating a modified version of this, simply becuase
it is effectively zero overhead, and it is nice to be able to reference a
module by name just for the hell of it.

I'll run a couple tests and see.

_alex