Recursive nesting of defined tags

[Jens Stimpfle]

Hi,

I've spent some time on the docs, but I fail to see how I would do the
following nicely in Mako: Define a menu structure with tags, and have it
construct HTML menus given (preferably exchangeable) tag definitions.

The input should look something like

<%submenu path="pflanzen">
<%menuitem path="index.html">
<%submenu path="moose">
<%submenu path="lebermoose">
<%menuitem path="brunnenlebermoos.html"/>
</%submenu>
<%submenu path="laubmoose">
<%menuitem path="torfmoos.html"/>
</%submenu>
<%submenu path="hornmoose">
<%menuitem path="glattes_hornmoos.html"/>
</%submenu>
</%submenu>

<%submenu path="Gef��fplanzen">
<%menuitem path="gemeine_kiefer.html"/>
</%submenu>
</%submenu>

Now I'd like to define %submenu and %menuitem so that they can access
their parents' environments. In particular, each tag should construct
its own path, e.g. pflanzen/moose/lebermoose/brunnenlebermoos.html.
But that's exactly what I fail at.

The only workaround I see is to define the tags so they create global
python values (something like self.attr.menustructure,
self.attr.currentdir), but I'd rather have them directly translate into
HTML.

Thanks in advance for your input.

Have a nice day
Jens Stimpfle

[Michael Bayer]

On Jan 11, 2013, at 9:56 AM, Jens Stimpfle wrote:

> Hi,
>
> I've spent some time on the docs, but I fail to see how I would do the
> following nicely in Mako: Define a menu structure with tags, and have it
> construct HTML menus given (preferably exchangeable) tag definitions.
>
> The input should look something like
>
> <%submenu path="pflanzen">
> <%menuitem path="index.html">
> <%submenu path="moose">
> <%submenu path="lebermoose">
> <%menuitem path="brunnenlebermoos.html"/>
> </%submenu>
> <%submenu path="laubmoose">
> <%menuitem path="torfmoos.html"/>
> </%submenu>
> <%submenu path="hornmoose">
> <%menuitem path="glattes_hornmoos.html"/>
> </%submenu>
> </%submenu>
>

> <%submenu path="Gefäßfplanzen">

> <%menuitem path="gemeine_kiefer.html"/>
> </%submenu>
> </%submenu>
>
> Now I'd like to define %submenu and %menuitem so that they can access
> their parents' environments. In particular, each tag should construct
> its own path, e.g. pflanzen/moose/lebermoose/brunnenlebermoos.html.
> But that's exactly what I fail at.

>
> The only workaround I see is to define the tags so they create global
> python values (something like self.attr.menustructure,
> self.attr.currentdir), but I'd rather have them directly translate into
> HTML.

there's an explicit way to do it, but you probably won't want to use it in this context since it is too verbose - the tags accept an argument called "args" that's used to pass data into the body callable, you can re-send this to the enclosing tag:

<%def name="submenu(path, parent=None)">
<submenu path="${parent or ''}/${path}">
${caller.body(path=path)}
</submenu>
</%def>

<%def name="menuitem(path, parent=None)">
<menu path="${parent or ''}/${path}">${caller.body(path=path)}</menu>
</%def>


<%self:submenu path="pflanzen" args="path">
<%self:menuitem path="index.html" parent="${path}" args="path"/>
</%self:submenu>


the other way is to just establish a nesting context somewhere as you are doing. When I do form libraries I typically hang some attributes like this off of the Pylons' "c." object, or some analogue. It is just a stack after all so it's safe to set up/tear down as your tags render. I hadn't thought of using self.attr, actually, but that object is local to current run of that template so should be OK.