I'm working through this same example, and I'm having trouble understanding
how the following resolves:
value = (mode=='plus') and +1 or -1
Can anyone explain to me what is happening with this line of code?
On Monday, March 26, 2012 10:28:27 AM UTC-4, Omi Chiba wrote:
>
> OK it worked !
>
> The indent for last three line was wrong on book and it was fixed on the
> downloaded code.
>
>
>
> On Friday, March 23, 2012 6:18:36 PM UTC-5, Omi Chiba wrote:
>>
>> Alan,
>>
>> Thanks. Good idea. I will try the support files.
>>
>>
>> Sent from my Verizon Wireless BlackBerry
>>
>> -----Original Message-----
>> From: Alan Etkin <spame...@gmail.com>
>> Sender: web2py@googlegroups.com
>> Date: Fri, 23 Mar 2012 15:22:25
>> To: web2py-users<web2py@googlegroups.com <web2py@googlegroups.com>>
>> Reply-To: web2py@googlegroups.com
>> Subject: [web2py] Re: Cookbook Chapter 2 - Reddit clone Ajax problem
>>
>> I tested the example app with the book support files and it worked
>> (with Firefox 10 and web2py trunk). Maybe there is a bug fixed in the
>> app code that was not updated in the book's text.
>>
>> On 23 mar, 18:11, Omi Chiba <ochib...@gmail.com> wrote:
>> > I was following cookbook and having a problem for the ajax part. I can
>> > click plus or minus to change the value for the first time, but it
>> doesn't
>> > update the value next time it's clicked. Also, I don't get any flash
>> > message like 'you voted already' or 'vote recorded'.
>> >
>> > What am I missing ?
>> >
>> > Controller
>> > -----------------------------------------------
>> > def news_comments():
>> > news = db.news(request.args(0)) or redirect(URL('categories'))
>> > if auth.user:
>> > db.comment.news.default = news.id
>> > db.comment.posted_on.default = request.now
>> > db.comment.posted_by.default = auth.user.id
>> > form = crud.create(db.comment)
>> > comments =
>> > db(db.comment.news==news.id).select(orderby=db.comment.posted_on)
>> > return locals()
>> >
>> > @auth.requires_login()
>> > def vote():
>> > if not request.env.request_method=='POST': raise HTTP(400)
>> > news_id, mode = request.args(0), request.args(1)
>> > news = db.news(id=news_id)
>> > vote = db.vote(posted_by=auth.user.id, news=news_id)
>> > votes = news.votes
>> > value = (mode=='plus') and +1 or -1
>> > if vote and value*vote.value==1:
>> > message = 'you voted already'
>> > else:
>> > if vote:
>> > votes += value - vote.value
>> > vote.update_record(value=value)
>> > else:
>> > votes += value
>> > db.vote.insert(value=value, posted_by=auth.user.id,
>> > posted_on=request.now, news=news.id)
>> > news.update_record(votes=votes)
>> > message ='vote recorded'
>> > return "jQuery('#votes').html('%s');jQuery('.flash').\
>> > html('%s').slideDown();" % (votes, message)
>> >
>> > View - news_comment.html
>> > ---------------------------------
>> > {{extend 'layout.html'}}
>> > <h5>{{=A(news.title, _href=news.link)}}</h5>
>> > {{if auth.user:}}
>> > <span id="votes">{{=news.votes}}</span>
>> > <button id="plus" onclick="ajax('{{=URL('vote', args=(news.id,
>> 'plus'))}}',
>> > [], ':eval')">plus</button>
>> > <button id="minus" onclick="ajax('{{=URL('vote', args=(news.id,
>> > 'minus'))}}', [], ':eval')">minus</button>
>> > {{=form}}
>> > {{pass}}
>> > <table>
>> > {{for comment in comments:}}
>> > <tr>
>> > <td>{{=comment.posted_on}}</td>
>> > <td>{{=comment.posted_by.first_name}}: </td>
>> > <td>{{=MARKMIN(comment.body)}}</td>
>> > </tr>
>> > {{pass}}
>> > </table>
>
>
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