what is an ajax callback and how do i use it? what is it for?
On Thursday, 17 January 2013 03:16:38 UTC, rochacbruno wrote:
>
> models/foo.py
>
> # the thing table
> db.define_table("thing", Field("name"))
>
> # you may want to store likes on another table so you never allow a user
> to like the same thing twice
> db.define_table("thing_likes",
> Field("user", "reference auth_user", notnull=True),
> Field("thing", "reference thing", notnull=True),
> Field("unikey", unique=True, notnull=True)
> )
>
> # this ensure that user cannot like a thing twice
> db.thing_likes.unikey.compute = lambda row: "%(user)s-%(thing)s" % row
>
>
> controllers/default.py
>
> def show_thing():
> thing_id = request.args(0)
> thing = db.thing[thing_id]
> thing_likes = db(db.thing_likes.id == thing.id).count()
> return dict(thing=thing. thing_likes=thing_likes)
>
> def like_thing():
> thing_id = request.args(0)
> user_id = auth.user_id
> try:
> db.thing_likes.validate_and_insert(
> thing=int(thing_id),
> user=int(user_id)
> )
> redirect(URL('show_thing', args=thing_id))
> except:
> return "thing cannot be liked twice"
>
>
> views/default/show_thing.html
>
> <h1>{{=thing.name}}</h1>
> <a href="{{=URL('like_thing', args=thing.id)}}"> Like this thing </a>
>
>
> ========================
>
> To a better implementation you should use an ajax callback to the "like"
> button, and also you should check if user already likes to show a different
> button, maybe unlike.
>
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