Opened 8 years ago

Closed 8 years ago

#8951 closed (invalid)

Better support for writing more complex template tags

Reported by: simon Owned by: nobody
Component: Template system Version: 1.0
Severity: Keywords: djangocon
Cc: Triage Stage: Unreviewed
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: UI/UX:


Adrian and Jacob on stage at DjangoCon.

Change History (3)

comment:1 Changed 8 years ago by Eric Holscher

Needs documentation: unset
Needs tests: unset
Patch needs improvement: unset

bits[] needs to go away. Badly. Perhaps this and namespaces could be part of a ttag refactor? (and other ponies as well? :)

comment:2 Changed 8 years ago by bertrandnouvel

Component: UncategorizedTemplate system

Exemple o required fixups on tags and filters :

I try to write something a list of objects that are complex to render, and for which I will assign some specific "credentials" in a database while enumerating.
I would be happy to use a tag to simplify the rendering of these complex objects. However, things are not happenning like I expect. At first try, I did :

{%for o in listobject%}
 o1={{}}, o2={%tag arg%}

We coded (code included later) the tag using "oid=template.Variable(tok[1])" or Parser.compile_filter in the template tag, "oid.resolve(context)" in the render function.
Samething that simple_tag would have done.
However, the id of the first object of listobjects for o2, while o1 is correctly moving... This should be qualified as a bug since it is not the expected behaviour in a for loop...
I guess this is due to the fact that "for" and "endfor" are themselves tags.

The one would think about writing a filter, and to do {{|filter:arg}}, the problem of this approach is that in tags, I could access "context" to retrieve objects in the context,
the filter syntax does not provide access to context and supports only one argument, that is generally a string. If I want to access the my user profile (as I actually want)
I am stucked...

I believe generally that "request", "session", "context" objects should be easily accessible from tags and filters
Currently this is not the case.

I hope explanations of this kind of need can help make the next tag system better.

Code of the buggy tag :

def buggytag(parser,token):   
    class Node(template.Node):
        def __init__(self,oid,param):
        def render(self, context):
            if (type(self.oid)!=int) and (type(self.oid)!=long):
            return ('('+str(oid)+')'<span id="'+self.param+'"></span>'
    return Node(oid,param)

comment:3 Changed 8 years ago by Jacob

Resolution: invalid
Status: newclosed

Without a specific suggestion it's hard to know what to do here. Closing in favor of some of the other tickets 'round these parts that have specific suggestions/patches.

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