I have 3 datatables as follows:
db.define_table('songs',
Field('songname'),
format='%(songname)s')
db.define_table('likes',
Field('username', 'reference auth_user'),
Field('songname', 'reference songs'))
with the 3rd table being db.auth_user
I would like to implement a "like" button, where clicking it adds an entry
to the intermediate table 'likes'. For example, if User1 likes Song1, it
would perform the following:
db.likes.insert(username=auth.user.id, songname=1)
Right now I have the like button as the following in the view:
{{=A('like me', callback=URL('add_like'))}}
and the function as:
def add_like():
db.likes.insert(username=auth.user.id, songname=1)
The problem I'm having is that a user should only be allowed to 'like' a
song once; if the user has already liked the song, clicking on 'like' again
should remove that like. Basically a toggle functionality for the 'like'
button.
I'm not sure how to implement the last part, as it seems checking the
entire database for the existence of that record on every 'like' click is
overkill. Is there an eloquent way (minimal database calls) to go about
implementing this toggle functionality for a 'like' button?
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