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SelectTimeWidget

Author:
bradmontgomery
Posted:
November 18, 2008
Language:
Python
Version:
1.0
Score:
4 (after 4 ratings)

This snippet defines a Widget that is very similar to the SelectDateWidget located in django.forms.extras.widgets. The main difference however is that it works with Times instead of Dates.

The SelectTimeWidget supports both 24-hr and 12-hr formats, and flexible time increments for hours, minutes and seconds. Sample usage is illustrated below:

# Specify a basic 24-hr time Widget (the default)
t = forms.TimeField(widget=SelectTimeWidget())

# Force minutes and seconds to be displayed in increments of 10
t = forms.TimeField(widget=SelectTimeWidget(minute_step=10, second_step=10))

# Use a 12-hr time format, which will display a 4th select 
# element containing a.m. and p.m. options)
t = forms.TimeField(widget=SelectTimeWidget(twelve_hr=True))
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import re
from django.forms.extras.widgets import SelectDateWidget
from django.forms.widgets import Widget, Select, MultiWidget
from django.utils.safestring import mark_safe

__all__ = ('SelectTimeWidget', 'SplitSelectDateTimeWidget')

# Attempt to match many time formats:
# Example: "12:34:56 P.M."  matches:
# ('12', '34', ':56', '56', 'P.M.', 'P', '.', 'M', '.')
# ('12', '34', ':56', '56', 'P.M.')
# Note that the colon ":" before seconds is optional, but only if seconds are omitted
time_pattern = r'(\d\d?):(\d\d)(:(\d\d))? *([aApP]\.?[mM]\.?)?$'

RE_TIME = re.compile(time_pattern)
# The following are just more readable ways to access re.matched groups:
HOURS = 0
MINUTES = 1
SECONDS = 3
MERIDIEM = 4

class SelectTimeWidget(Widget):
    """
    A Widget that splits time input into <select> elements.
    Allows form to show as 24hr: <hour>:<minute>:<second>, (default)
    or as 12hr: <hour>:<minute>:<second> <am|pm> 
    
    Also allows user-defined increments for minutes/seconds
    """
    hour_field = '%s_hour'
    minute_field = '%s_minute'
    second_field = '%s_second' 
    meridiem_field = '%s_meridiem'
    twelve_hr = False # Default to 24hr.
    
    def __init__(self, attrs=None, hour_step=None, minute_step=None, second_step=None, twelve_hr=False):
        """
        hour_step, minute_step, second_step are optional step values for
        for the range of values for the associated select element
        twelve_hr: If True, forces the output to be in 12-hr format (rather than 24-hr)
        """
        self.attrs = attrs or {}
        
        if twelve_hr:
            self.twelve_hr = True # Do 12hr (rather than 24hr)
            self.meridiem_val = 'a.m.' # Default to Morning (A.M.)
        
        if hour_step and twelve_hr:
            self.hours = range(1,13,hour_step) 
        elif hour_step: # 24hr, with stepping.
            self.hours = range(0,24,hour_step)
        elif twelve_hr: # 12hr, no stepping
            self.hours = range(1,13)
        else: # 24hr, no stepping
            self.hours = range(0,24) 

        if minute_step:
            self.minutes = range(0,60,minute_step)
        else:
            self.minutes = range(0,60)

        if second_step:
            self.seconds = range(0,60,second_step)
        else:
            self.seconds = range(0,60)

    def render(self, name, value, attrs=None):
        try: # try to get time values from a datetime.time object (value)
            hour_val, minute_val, second_val = value.hour, value.minute, value.second
            if self.twelve_hr:
                if hour_val >= 12:
                    self.meridiem_val = 'p.m.'
                else:
                    self.meridiem_val = 'a.m.'
        except AttributeError:
            hour_val = minute_val = second_val = 0
            if isinstance(value, basestring):
                match = RE_TIME.match(value)
                if match:
                    time_groups = match.groups();
                    hour_val = int(time_groups[HOURS]) % 24 # force to range(0-24)
                    minute_val = int(time_groups[MINUTES]) 
                    if time_groups[SECONDS] is None:
                        second_val = 0
                    else:
                        second_val = int(time_groups[SECONDS])
                    
                    # check to see if meridiem was passed in
                    if time_groups[MERIDIEM] is not None:
                        self.meridiem_val = time_groups[MERIDIEM]
                    else: # otherwise, set the meridiem based on the time
                        if self.twelve_hr:
                            if hour_val >= 12:
                                self.meridiem_val = 'p.m.'
                            else:
                                self.meridiem_val = 'a.m.'
                        else:
                            self.meridiem_val = None
                    

        # If we're doing a 12-hr clock, there will be a meridiem value, so make sure the
        # hours get printed correctly
        if self.twelve_hr and self.meridiem_val:
            if self.meridiem_val.lower().startswith('p') and hour_val > 12 and hour_val < 24:
                hour_val = hour_val % 12
        elif hour_val == 0:
            hour_val = 12
            
        output = []
        if 'id' in self.attrs:
            id_ = self.attrs['id']
        else:
            id_ = 'id_%s' % name

        # For times to get displayed correctly, the values MUST be converted to unicode
        # When Select builds a list of options, it checks against Unicode values
        hour_val = u"%.2d" % hour_val
        minute_val = u"%.2d" % minute_val
        second_val = u"%.2d" % second_val

        hour_choices = [("%.2d"%i, "%.2d"%i) for i in self.hours]
        local_attrs = self.build_attrs(id=self.hour_field % id_)
        select_html = Select(choices=hour_choices).render(self.hour_field % name, hour_val, local_attrs)
        output.append(select_html)

        minute_choices = [("%.2d"%i, "%.2d"%i) for i in self.minutes]
        local_attrs['id'] = self.minute_field % id_
        select_html = Select(choices=minute_choices).render(self.minute_field % name, minute_val, local_attrs)
        output.append(select_html)

        second_choices = [("%.2d"%i, "%.2d"%i) for i in self.seconds]
        local_attrs['id'] = self.second_field % id_
        select_html = Select(choices=second_choices).render(self.second_field % name, second_val, local_attrs)
        output.append(select_html)
    
        if self.twelve_hr:
            #  If we were given an initial value, make sure the correct meridiem gets selected.
            if self.meridiem_val is not None and  self.meridiem_val.startswith('p'):
                    meridiem_choices = [('p.m.','p.m.'), ('a.m.','a.m.')]
            else:
                meridiem_choices = [('a.m.','a.m.'), ('p.m.','p.m.')]

            local_attrs['id'] = local_attrs['id'] = self.meridiem_field % id_
            select_html = Select(choices=meridiem_choices).render(self.meridiem_field % name, self.meridiem_val, local_attrs)
            output.append(select_html)

        return mark_safe(u'\n'.join(output))

    def id_for_label(self, id_):
        return '%s_hour' % id_
    id_for_label = classmethod(id_for_label)

    def value_from_datadict(self, data, files, name):
        # if there's not h:m:s data, assume zero:
        h = data.get(self.hour_field % name, 0) # hour
        m = data.get(self.minute_field % name, 0) # minute 
        s = data.get(self.second_field % name, 0) # second

        meridiem = data.get(self.meridiem_field % name, None)

        #NOTE: if meridiem is None, assume 24-hr
        if meridiem is not None:
            if meridiem.lower().startswith('p') and int(h) != 12:
                h = (int(h)+12)%24 
            elif meridiem.lower().startswith('a') and int(h) == 12:
                h = 0
        
        if (int(h) == 0 or h) and m and s:
            return '%s:%s:%s' % (h, m, s)

        return data.get(name, None)

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Comments

mhulse (on June 13, 2011):

I am personally using the code found on Github; there are other forks out there too, just search Google for "SelectDateWidget Django".

Being relatively new to Django, it took me a few to figure out how to get this applied to my model and working right in the admin. For those of you that are in the same boat, here's how I got it working:

Put the widget on your system (I put mine in a widgets folder because I had other widget files) and then create (or add to) forms.py:

from django import forms
from dee.widgets.select_time_widget import * # See __all__.
from app.models import Foo

class FooForm(forms.ModelForm):

class Meta:
    model = Foo

time = forms.TimeField(widget=SelectTimeWidget(twelve_hr=True, use_seconds=False, required=False), required=False, label=u'Time')

And in my admin.py:

from django.contrib import admin
from django.db import models
from app.forms import FooForm
from app.models import Foo

class FooAdmin(admin.ModelAdmin):
    form = FooForm
    # ...

admin.site.register(Foo, FooAdmin)

If you have any inlines, don't forget to add form = GameForm to those also.

I hope that helps someone. :)

BTW, it would be cool if this snippet had an option to change the default a.m./p.m. value (i.e. show p.m. by default would be nice).

#

Skrubly (on December 28, 2011):

Thanks for this widget! I'm using it in conjunction with your SplitSelectDateTimeWidget.

I did notice a bug - I am using 24 hour time and my initial values are for 00:00:00, but it kept rendering as 12:00:00. It seems that on line 106 it will change hour_val to 12 regardless of whether you are using the 12 hour clock. I changed it from:

elif hour_val == 0:

to

elif self.twelve_hr and hour_val == 0:

and that seems to have solved my problem.

I've been learning django for about two months - this snippet has been a great help!

#

dragonx (on March 1, 2012):

Ran into the same issue as Skrubly, I indented lines 106/107 one over to make it work.

#

siddharth91 (on December 11, 2015):

How can i make it to accept null values? My time field can be null , but by default it shows 12:00:00

#

Exceclsior7574 (on December 7, 2016):

I have the same question as siddharth91. I tried making the default value null but it keeps storing 12:00:00 and shows midnight on my app. Great snippet otherwise. I am incorporating it in my work project. Can anyone please help me out at the earliest? Thanks in advance!

#

Exceclsior7574 (on December 9, 2016):

Any suggestions?

#

Exceclsior7574 (on December 14, 2016):

For those of you having the same problem as me, please refer ramens mod version of the above timepicker on github. Please refer the following link: https://github.com/ramen/django-select-time-widget

Thank me later

#

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