But why not this which seems much more readble?
value = +1 if mode == 'plus' else -1
On Tuesday, July 24, 2012 10:20:51 PM UTC+1, pjryan126 wrote:
>
> 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>
>>
>>
On Tuesday, July 24, 2012 10:20:51 PM UTC+1, pjryan126 wrote:
>
> 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>
>>
>>
--
