Setting the selected option of a SELECT element

From the mailing list ...

On 11/2/05, Jaime Wyant <programmer.py@gmail.com> wrote:

<!--
     I want to `set' the selection based on the character.ascended expression.
    This just seems clunky.
-->
<select py:if="$character.ascended" name="ascended">
    <option  value="True" selected="selected">True</option>
    <option value="False">False</option>
</select>

<select py:if="not $character.ascended" name="ascended">
    <option  value="True">True</option>
    <option value="False" selected="selected">False</option>
</select>

Yes, that would be painful to have to do that everywhere... There was another thread on this recently, which shows that we need to add some documentation about this.

<select name="ascended">
   <option value="True" py:attrs="selected=std.selector(character.ascended)">True</option>
   <option value="False" py:attrs="selected=std.selector(not character.ascended)">False</option>
</select>

Dynamic select boxes

This can be easily extended to dynamic select boxes, for example:

from model import YourDataType

class YourController:
    @turbogears.expose(html='yourtemplate')
    def index(self):
        items = YourDataType.select()
        # item_id is used to added the "selected" attribute
        #  to the correct <option>
        # Below is just for example: in reality, this value would be pulled from
        #  another SQLObject (or other source)
        item_id = 3
        return dict(items = items, item_id = item_id)

Then in the template:

<select name="the_item">
   <option py:for="i in items" value="${i.id}"
       py:attrs="selected=std.selector(i.id == item_id)">
       ${i.name}</option>
</select>