How can I make a calculation in the view?

[greenpoise]

I have seen examples on how to calculate on DAL level using lambda. Could someone post an example (or point me to) of calculating values in the view? after an sql retrieval? or sql in the view? 

Thanks

[黄祥]

just do like usual in controller

e.g.

controllers/default.py

def report_investor():

choose_investor = request.args(0)

# query

query_account = (db.account.investor == choose_investor)

# row

rows_account = db(query_account).select(orderby = ~db.account.id)

return dict(rows_account = rows_account)

views/default/report_investor.html

<table class = 'detail'>

<tbody>

<th class = 'border'>

{{=SPAN(T('P/L') ) }}

<br />

{{=SPAN(T('P/L (%)') ) }}

</th>

<th class = 'border'>

{{=SPAN(T('Net P/L') ) }}

<br />

{{=SPAN(T('Net P/L (%)') ) }}

</th>

</tr>

{{for row_account in rows_account:}}

<tr>

{{

profit_loss_value = row_account.balance - row_account.subscription_amount

profit_loss_percentage = (profit_loss_value / row_account.subscription_amount) * 100 if row_account.subscription_amount > 0 else 0

}}

<td class="text-right border">

{{=SPAN('%s %s' % (row_account.product.currency.symbol, locale.format("%.2f", profit_loss_value, grouping = True) ), _class = 'red' if profit_loss_value <= 0 else 'green') }}

<br />

{{=SPAN('%s %%' % (locale.format("%.2f", profit_loss_percentage, grouping = True) ), _class = 'red' if profit_loss_percentage <= 0 else 'green') }}

</td>

{{

net_subscription = row_account.subscription_amount + row_account.subscription_fee + row_account.redemption_fee

net_profit_loss_value = row_account.balance - net_subscription

net_profit_loss_percentage = (net_profit_loss_value / net_subscription) * 100 if net_subscription > 0 else 0

}}

<td class="text-right border">

{{=SPAN('%s %s' % (row_account.product.currency.symbol, locale.format("%.2f", net_profit_loss_value, grouping = True) ), _class = 'red' if net_profit_loss_value <= 0 else 'green') }}

<br />

{{=SPAN('%s %%' % (locale.format("%.2f", net_profit_loss_percentage, grouping = True) ), _class = 'red' if net_profit_loss_percentage <= 0 else 'green') }}

</td>

</tr>

{{pass}}

</tbody>

</table>

best regards,

stifan

[Anthony]

Though generally it is good to minimize the logic in views, as they are more difficult to read, test, and debug. So, prefer moving such calculations to the controller, or at least to a function that is simply called from the view.

Anthony

[greenpoise]

Thanks a million.

[greenpoise]

I see. Thanks Anthony